Design, synthesis and structure-activity relationships of novel 15-membered macrolides: Quinolone/quinoline-containing sidechains tethered to the C-6 position of azithromycin acylides

Article abstract of DOI:10.1016/j.ejmech.2020.112222

In the search for novel hybrid molecules by fusing two biologically active scaffolds into one heteromeric chemotype, we found that hybrids of azithromycin and ciprofloxacin/gatifloxacin 26j and 26l can inhibit the supercoiling activity of E. coli gyrase by poisoning it in a way similar to fluoroquinolones. This may modestly contribute to their potencies, which are equal to ciprofloxacin against constitutively resistant Staphylococcus aureus, whose growth is not inhibited by the presence of macrolides. In contrast, introduction of quinolines (the 3-quinoline 26b and the 6-quinoline 26o) with an optimized rigid spacer at the 6-OH of azithromycin acylides did not exert significant potency against constitutively resistant S. aureus, despite the fact that the quinoline-containing compounds, exemplified by 26o, were as active as telithromycin against susceptible, inducibly- and efflux-resistant pathogens. The novel dual modes of action involving protein synthesis inhibition and poisoning DNA replication may pave the way for restoration of antibacterial activities of the current macrolides against constitutively resistant clinical isolates.

Full text of DOI:10.1016/j.ejmech.2020.112222

European Journal of Medicinal Chemistry 193 (2020) 112222
Contents lists available at ScienceDirect
European Journal of Medicinal Chemistry
journal homepage: http://www.elsevier.com/locate/ejmech
Research paper
Design, synthesis and structure-activity relationships of novel 15-
membered macrolides: Quinolone/quinoline-containing sidechains
tethered to the C-6 position of azithromycin acylides
a
b
c
d
e
Bing-Zhi Fan , Hiroshi Hiasa , Wei Lv , Scott Brody , Zhao-Yong Yang ,
d
c
a, d, *
Courtney Aldrich , Mark Cushman , Jian-Hua Liang
School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, 100081, China
a
b
c
Department of Pharmacology, University of Minnesota Medical School, Minneapolis, MN, 55455, United States
Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, West Lafayette, 47907, United States
Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, Minneapolis, MN, 55455, United States
NHC Key Laboratory of Biotechnology of Antibiotics, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences, Beijing, 100050, China
d
e
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 22 December 2019
Received in revised form
In the search for novel hybrid molecules by fusing two biologically active scaffolds into one heteromeric
chemotype, we found that hybrids of azithromycin and ciprofloxacin/gatifloxacin 26j and 26l can inhibit
the supercoiling activity of E. coli gyrase by poisoning it in a way similar to fluoroquinolones. This may
modestly contribute to their potencies, which are equal to ciprofloxacin against constitutively resistant
Staphylococcus aureus, whose growth is not inhibited by the presence of macrolides. In contrast, intro-
duction of quinolines (the 3-quinoline 26b and the 6-quinoline 26o) with an optimized rigid spacer at
the 6-OH of azithromycin acylides did not exert significant potency against constitutively resistant
S. aureus, despite the fact that the quinoline-containing compounds, exemplified by 26o, were as active
as telithromycin against susceptible, inducibly- and efflux-resistant pathogens. The novel dual modes of
action involving protein synthesis inhibition and poisoning DNA replication may pave the way for
restoration of antibacterial activities of the current macrolides against constitutively resistant clinical
isolates.
9
March 2020
Accepted 9 March 2020
Available online 14 March 2020
Keywords:
Macrolide
Quinolone
Hybrid
Dual modes of action
Ribosome
Topoisomerase
©
2020 Elsevier Masson SAS. All rights reserved.
1
. Introduction
extended antimicrobial spectrum. However, the use of azi-
thromycin has decreased due to globally emerging antibiotic
resistance. A recent international surveillance indicated that azi-
thromycin is only effective against 62.2% of Streptococcus pneumo-
niae and 58.7% of Staphylococcus aureus strains [2]. Therefore, the
search for an effective chemotype is becoming more urgent.
The underlying resistance mechanism is that azithromycin is an
inducer of expression of erm genes (erythromycin ribosomal
methylase), which in turn mono- or dimethylates the amino group
of A2058Ec (Escherichia coli numbering), a vital binding site that is
located in bacterial nascent peptide exit tunnel (NPET). The
methylation results in dramatically decreased affinity of azi-
thromycin to bacterial ribosomes. Alternative inducible resistance
is mediated by mef-encoding efflux proteins, which facilitate the
efflux of drug molecules outside the cell and reduce antibiotics’
concentration below the effective level when encountering the
target [3e5]. The ability to induce resistance should be eradicated,
because it is responsible for the recent increases in clinical
The ribosome is the most important target for antibiotics
because it is the target of over half of the antibiotics approved for
clinical use. Among them, azithromycin is a long-acting macrolide
antimicrobial agent (Fig. 1), which is widely prescribed for curing
upper and lower respiratory tract infections. It is characterized by
an uncommon aza-15-membered scaffold, which is synthesized by
Beckmann rearrangement of erythromycin oxime followed by hy-
drogenation and methylation [1]. Compared to erythromycin
(Fig. 1), azithromycin possesses not only improved pharmacoki-
netic properties (for example, enhanced acid-stability in the
stomach and high tissue distribution in the lung) but also an
*
Corresponding author. School of Chemistry and Chemical Engineering, Beijing
Institute of Technology, Beijing, 100081, China.
E-mail address: ljhbit@bit.edu.cn (J.-H. Liang).
https://doi.org/10.1016/j.ejmech.2020.112222
0223-5234/© 2020 Elsevier Masson SAS. All rights reserved.

2
B.-Z. Fan et al. / European Journal of Medicinal Chemistry 193 (2020) 112222
Fig. 1. Structures of the erythromycin, azithromycin, and telithromycin.
resistance and treatment failure. It was found that cladinose,
attached to C-3 of the macrolide, plays an important role in in-
duction of the two types of resistance [6,7]. For this reason, the 4"-
position of cladinose was structurally modified to circumvent the
induction [1,8,9]. However, a more attractive strategy is the
replacement of cladinose by means of MIC-guided structural opti-
mization, and the resulting non-inducers are known as ketolides
Despite strenuous efforts on the SARs of macrolides [1,8,9], there
are reasons that support continued study. First, constitutive resis-
tance is at a much higher level in comparison with inducible and
efflux-mediated resistance. Furthermore, it was reported that
mutational frequency in clinical isolates with constitutive resis-
tance is > 57-fold and >3333-fold higher than the inducibly resis-
tant and erythromycin-susceptible strains, respectively [27]. Thus,
novel ribosome binding sites or novel modes of action that are
different from those of telithromycin need to be identified in order
to fight against the constitutively resistant bacteria. Second, none of
the macrolides show high activities against constitutively resistant
S. aureus. An improvement was disclosed by Pavlovic regarding
hybrids of quinolones and 8a-azahomoerythromycin ketolides
(Fig. 2) [28]. Although these hybrids were 16e64 fold weaker than
ciprofloxacin, the results suggest that promising candidates against
constitutively resistant S. aureus may emerge from 15-membered
macrolides. Third, SARs of macrolones and their modes of action
are not fully explored yet. Except for some C-6 modified (homo)
erythromycin ketolides [28,29], the SAR is unclear regarding azi-
thromycin acylides having quinolones tethered to C-6 position
[30,31]. Previously, we found that SARs of acylides are distinct from
those of ketolides, probably due to the easily twisted profiles of the
flexible macrolides [32,33].
(
3-keto) or acylides (3-O-acyl) [10e12]. Since the natural 3-keto
macrolide picromycin, which was discovered in 1950s, is inactive,
the discovery of the synthetic ketolides and acylides disproved the
long-held notion that cladinose is necessary to maintain the ac-
tivities of the macrolides [4,8].
The expression of A2058 methylase can be inducible or consti-
tutive. In the latter case, the binding site A2058 would be consti-
tutively methylated by methylase in absence of the inducers,
leading to high-level resistance. Unfortunately, conversion of the
cladinose to keto or acyl groups does not restore the activities of the
non-inducers against constitutively resistant bacteria [11,12].
Constitutively resistant bacteria, unlike inducible ones, are cor-
esistant to chemically unrelated macrolides, lincosamides, and
B
streptogramin B (MLS ), which have overlapping binding sites in
the bacterial NPET. Thus, non-inducers’ inability to restore the ac-
tivity against constitutively resistant bacteria required the search
for an additional high-affinity binding site. This led to telithromycin
To broaden the SAR of macrolones and their modes of action, we
have investigated novel acylide-type macrolones obtained by direct
acrylation at the C-6 position of azithromycin followed by facile
diversification via Michael addition. As reported herein, the
(Fig. 1), a 14-membered ketolide, which is the first and thus far only
marketed erythromycin derivative with the restored activity
against erythromycin-resistant pathogens. It has a sidechain at the
11-N carbamate cyclized to the 12-OH, which supplies a key
structural element for binding to the base pair A752/U2609 [13,14].
Telithromycin possesses improved activities against constitutively
resistant S. pneumoniae and Streptococcus pyogenes, but not against
constitutively resistant S. aureus. In addition to telithromycin, at
least five 14-membered ketolides are in clinical trials. Although 15-
membered azithromycin possesses better PK and safety profiles,
none of the azithromycin analogs have entered clinical trials.
To search for novel chemicals with new modes of action, quin-
olones were tethered to the 4"-position of the cladinose of azi-
thromycin or 6-O-methylerythromycin (clarithromycin), and the
hybrids were named macrolones [15e23]. 3-Carboxy-4-quinolones
are the key pharmacophores that target bacterial DNA gyrase or
topoisomerase IV [24,25]. However, extensive studies indicated
that the macrolones retained their activities as strong protein
synthesis inhibitors and proved to be devoid of DNA gyrase and
topoisomerase IV inhibitory activity [22,26]. The lack of the dual
mode was corroborated by the full potency of the macrolones
against quinolone-resistant S. aureus strains [26]. Therefore, the
researchers concluded that the macrolones did not exhibit their
antibacterial activities through a quinolone mode of action [26].
Fig. 2. Structure of the 8a-aza-8a homoerythromycin A ketolide with improved ac-
tivity against constitutively resistant S. aureus (2e8
floxacin vs > 64 g/mL of telithromycin).
mg/mL vs 0.125 mg/mL of cipro-
m

B.-Z. Fan et al. / European Journal of Medicinal Chemistry 193 (2020) 112222
3
products had enhanced activities against inducibly resistant, efflux-
resistant and constitutively resistant pathogens.
intermediates 8a and 9a were prepared by Heck coupling, followed
by treatment with hydrazine hydrate to afford the amines 12a and
13a. The amines 14a and 15a were obtained by reduction of 8a and
9a and subsequent reaction with hydrazine hydrate. Since basic
2
. Results and discussion
hydrolysis of 11i resulted in unidentified products, another pro-
cedure for 11j was sought by hydrazinolysis of 3, Boc-protection,
Sonogashira coupling and deprotection (Scheme 2). The ciproflox-
acin derivative 20 was prepared in three steps: Boc-protection of
ciprofloxacin (18), conversion of 19 to the corresponding amide,
and subsequent deprotection (Scheme 3).
2.1. Chemistry
The synthetic routes leading to the amines 10a, 11a-11j, 12a, 13a,
14a, 15a and 20 are outlined in Schemes 1e3. Commercially avail-
able phthalimide (1) was reacted with different reagents (propargyl
bromide, but-3-yn-1-ol, allyl bromide or 4-bromobut-1-ene) under
different conditions to provide the alkynes and alkenes (2, 3, 4 and
The preparations of the target compounds 26 series, 29 series
and 31 series are shown in Schemes 4 and 5 and Chart 1. First, 3-O-
cladinose was selectively removed from azithromycin (21) with 1 M
0
5
). Compounds 6a and 7a-7j were synthesized by Sonogashira
HCl in the presence of EtOH. Next, the 2 -OH was protected by
coupling, followed by treatment with hydrazine hydrate to yield
acetylation to give 22 with unprotected hydroxyls at the 3-, 6-, 11-,
the amines 10a and 11a-11i. However,11j was not obtained because
and 12-positions. It was reported that acrylation occurred easily at
7
j did not react in the hydrazinolysis reaction. In a similar way,
ꢀ
Scheme 1. Synthesis of compounds 10a, 11a-11i, 12a, 13a, 14a and 15a. Reagents and conditions: (a) 3-butyn-1-ol, PPh
3
, DIAD, toluene, 0 C for 10 min, then rt for 1 h; or propargyl
bromide or allyl bromide or 4-bromo-1-butene, KOH, EtOH, rt for 2 h, then reflux in DMF for 72 h; (b) ArX, CuI, bis(triphenylphosphine)palladium(II) dichloride, triethylamine,
ꢀ
ꢀ
ꢀ
acetonitrile, 80 C, 4 h; (c) ArX, Pd(OAc) , tri-o-tolylphosphine, triethylamine, acetonitrile, 60 C for 1 h, then 90 C for 24 h; (d) 80% hydrazine hydrate, EtOH, reflux; (e) ammonium
2
ꢀ
formate, HCOOH, 10% Pd/C, MeOH, 65 C, 24 h.

4
B.-Z. Fan et al. / European Journal of Medicinal Chemistry 193 (2020) 112222
ꢀ
Scheme 2. Synthesis of compound 11j. Reagents and conditions: (a) 80% hydrazine hydrate, EtOH, reflux; then HCl; (b) di-tert-butyl dicarbonate, triethylamine, THF, 0 C for 10 min,
ꢀ
ꢀ
then rt for 24 h; (c) ArX, CuI, bis(triphenylphosphine)palladium(II) dichloride, triethylamine, acetonitrile, 50 C, 24 h; (d) HCl, EtOAc, 0 C for 10 min, then rt for 3 h.
ꢀ
ꢀ
Scheme 3. Synthesis of compound 20. Reagents and conditions: (a) di-tert-butyl dicarbonate, triethylamine, THF, 0 C for 10 min, then rt for 8 h; (b) CDI, DMF, 65 C for 2 h, then
ꢀ
3 2
NH $H O, rt for 2 h; (c) HCl, EtOAc, 0 C for 10 min, then rt for 3 h.
ꢀ
Scheme 4. Synthesis of compounds 26a-26u and 26w. Reagents and conditions: (a) 1 M HCl, EtOH, 40 C, 1 h; (b) Ac
2
O, CH
2
Cl
2
, rt, 1 h; (c) 3-chloropropionyl chloride, triethylamine,
ꢀ
ꢀ
acetonitrile, 80 C; (d) 3-chloropropionyl chloride, triethylamine, toluene, rt; (e) 2-pyridylacetic acid hydrochloride, DCC, pyridine, DMAP, CH
2
Cl
2
, 0 C; (f) MeOH, reflux, 2 h; (g)
ꢀ
amines (a-u, w; Chart 1), N,N-diisopropylethylamine, MeOH, 65 C, 8 h.
the secondary 4"-OH of the cladinose [34]. Although the tertiary 6-
OH is highly sterically hindered, treatment 22 with 3-
chloropropionyl chloride in toluene at room temperature regiose-
lectively yielded the acrylation derivative at 6-OH (24). We found
that diacrylation would occur at both 6-OH and 3-OH (23) in
acetonitrile at elevated temperature. The structures of the acylated
DEPT and 13C NMR spectral data. Then, esterification of the 3-OH
produced the acylide 25 by treatment of 24 with 2-pyridineacetic
acid hydrochloride in the presence of DCC, pyridine and DMAP.
The downshift of H-3 in 24’s NMR spectrum proved that 3-OH of 24
was successfully acylated to yield 25. The target compounds 26a-
0
26w were obtained by Michael addition to 2 -O-deacetyl-25 with a
variety of amines in the presence of an excess of N,N-
1
products 23 and 24 were determined by analyzing their H, COSY,

B.-Z. Fan et al. / European Journal of Medicinal Chemistry 193 (2020) 112222
5
, -10 C ~ ꢁ5 ꢀC for 4 h, then rt for
ꢀ
Scheme 5. Synthesis of compounds 29j, 29k, 29r, 29w, 31r and 31w. Reagents and conditions: (a) bis(trichloromethyl)carbonate, pyridine, CH
2
Cl
2
ꢀ
2
h; (b) 2-pyridylacetic acid hydrochloride or 3-pyridylacetic acid hydrochloride, DCC, pyridine, DMAP, CH
2
Cl
2
, 0 C; (c) MeOH, reflux, 2 h; (d) amines (j, k, r, w; Chart 1), N,N-
ꢀ
diisopropylethylamine, MeOH, 65 C, 8 h.
0
diisopropylethylamine after methanolysis of the 2 -O-acetate
Scheme 4). No addition reaction was found to yield 26v in the
are listed in Table 1. The strains include Gram-positive bacteria such
as S. aureus, S. pneumoniae and S. pyogenes, and Gram-negative
(
presence of 11i. Cyclic carbonation at 11-OH and 12-OH (27) and
acylation at the 3-OH (28 and 30) further corroborate the structural
correctness of 24. Finally, the target compounds 29 (29j, 29k, 29r
and 29w) and 31 (31r and 31w) were obtained in a way that is
similar to the synthesis of 26 (Scheme 5).
pathogens such as H. influenzae. The constitutive MLS
B
pheno-
types were differentiated from inducible MLS
types according to a triple-disk test [35].
B
and efflux pheno-
All of the compounds listed in Table 2 showed enhanced activ-
ities against resistant strains compared to parent azithromycin.
Among the hybrids of macrolides and quinolones bridged by linkers
of various length (26g, 26h, 26i and 26j), 26h possessing a linear
propanediamine sidechain was the most active. However, 26h was
inactive against S. aureus 15B196 containing a constitutive erm
gene. Against constitutively resistant S. pneumoniae 07P390, 26g
and 26h (6-quinolones) were 4- to 8-fold more potent than 26i and
26j (7-quinolones), which indicated that the attachment positions
2
2
.2. Structure-activity relationships of azithromycin acylides
.2.1. Variation of the linker lengths and configuration at the 6-OH
of azithromycin
The phenotypes (inducible, constitutive and efflux) and geno-
types (mef and erm) of the resistant bacteria were determined and
Table 1
Selected organisms and their resistant phenotypes and genotypes.
Strain
Phenotype
Genotype
Streptococcus pneumoniae
Streptococcus pneumoniae
Streptococcus pneumoniae
Streptococcus pyogenes
Staphylococcus aureus
Staphylococcus aureus
Haemophilus influenzae
ATCC 49619
PU 09
07P390
12e206
PU 32
15B196
Erythromycin-susceptible
Efflux, PSSP
none
mef
a
MLS
MLS
MLS
MLS
B
B
B
B
-resistantb (constitutive)
-resistant (constitutive)
-resistant (inducible), MRSA , Ciprofloxacin-resistant
ermB
ermA
ermA
c
d
-resistant (constitutive), MRSA
NT
ATCC 49247
Azithromycin-susceptible
none
a
PSSP: penicillin-susceptible Streptococcus pneumoniae.
MLS : macrolide-lincosamide-streptogramin B.
B
MRSA: methicillin-resistant Staphylococcus aureus.
NT: not tested.
b
c
d

6
B.-Z. Fan et al. / European Journal of Medicinal Chemistry 193 (2020) 112222
Table 2
Antibacterial activity of 26a-26j against erythromycin-susceptible and -resistant pathogens.
Compound
MIC and MBC (mg/mL)
S. pneumoniae ATCC 49619
S. pneumoniae PU 09 efflux
S. pneumoniae 07P390 constitutive
a
MLS
MIC
256
B
MIC
MBC
MBC/MIC
MIC
MBC
MBC/MIC
MBC
MBC/MIC
AZMb
0.062
0.25
4
1
8
0.25
16
0.5
2
2
>256
e
c
TEL
ꢂ0.008
ꢂ0.008
0.016
>0.125
>8
26 series
2
6a
6b
0.125
0.062
0.125
0.125
1
2
2
1
2
1
1
1
1
>8
>4
>8
>8
2
0.5
2
2
6c
0.125
0.125
0.25
2
1
2
1
2
1
1
1
1
4
>8
>8
>8
6d
0.125
>32
2
6e
6f
0.062
0.25
0.062
0.5
1
2
2
4
4
4
2
1
2
8
16
32
8
4
2
2
2
2
2
6g
6h
6i
0.25
0.25
0.125
0.5
1
1
2
2
4
1
4
2
4
1
4
4
1
1
1
2
1
1
8
4
>8
>8
>64
32
>8
>8
>8
8
0.125
0.25
6j
0.125
0.25
Compound
MIC and MBC (mg/mL)
d
S. aureus PU 32 MRSA , inducible
S. aureus 15B196 MRSA,
constitutive MLS
H. influenzae ATCC 49247
MLS
B
B
MIC
MBC
MBC/MIC
MIC
MBC
MBC/MIC
MIC
MBC
MBC/MIC
AZM
CFXe
32
64
32
>256
1
>4
>256
0.5
>256
0.5
e
2
8
4
2
1
0.004
0.008
26 series

B.-Z. Fan et al. / European Journal of Medicinal Chemistry 193 (2020) 112222
7
Table 2 (continued )
Compound
MIC and MBC (
mg/mL)
d
S. aureus PU 32 MRSA , inducible
S. aureus 15B196 MRSA,
constitutive MLS
H. influenzae ATCC 49247
MLS
MIC
2
B
B
MBC
8
MBC/MIC
4
MIC
128
MBC
MBC/MIC
MIC
4
MBC
4
MBC/MIC
1
2
6a
6b
>256
>256
e
2
1
>8
>8
128
e
2
4
2
2
2
6c
2
2
>16
>8
>256
e
e
8
8
16
16
2
2
6d
8
4
64
>256
>4
2
2
6e
6f
4
4
32
16
8
4
>256
e
e
e
16
16
16
32
1
2
256
>256
2
2
2
2
6g
6h
6i
8
>64
>8
>8
>8
>8
>256
>256
>256
16
e
e
e
e
8
16
16
4
32
64
8
2
4
2
1
8
>64
e
16
16
>128
>128
e
6j
128
0.25
0.25
a
b
c
B
MLS : macrolide-lincosamide-streptogramin B.
AZM: azithromycin.
TEL: telithromycin.
MRSA: methicillin-resistant Staphylococcus aureus.
CFX: ciprofloxacin.
d
e
of the linkers at C-6 and C-7 of the quinolones are important.
Compound 26j, with a cyclic piperazine ring that differentiates it
from the other macrolones 26g, 26h and 26i, showed improved
presented in Table 3, 26b is much more active than 26h, regardless
of the bacterial phenotypes and genotypes, although both share the
same sidechain length. However, the antibacterial spectra of the
hybrids are basically similar to those of conventional macrolides.
activity with an MIC of 16 mg/mL against constitutively resistant
S. aureus 15B196, and 26j was 8-fold more active than azithromycin
against H. influenzae ATCC49247.
2
.2.3. Variation of aryl groups at the end of the linkers at the 6-OH
To understand the impact of sidechain rigidity on activity, we
examined the MIC values of 26a - 26f (Ar ¼ quinoline) and found
of azithromycin
Taking advantage of the data in Tables 2 and 3, we fixed the
sidechain as in 26b, and further uncovered the effects of aryl groups
2
6b, with a butynyl sidechain, showed better potency in compari-
son with the corresponding olefin 26d and the flexible alkane 26f.
Compound 26b also compared favorably with the one-atom shorter
homologs (26a, 26c and 26e).
(see Chart 1) on activities. Among the analogs of 26b (the pyridine
2
2
6q, the quinoline 26o and quinolones 26p, 26r, 26s, 26t, 26u,
6w), 26o with a 6-quinolyl group was the most active (Table 4). It
was as active as telithromycin against susceptible S. pneumoniae
ATCC49619, efflux-mediated S. pneumoniae PU 09, inducibly resis-
tant erm-encoded S. aureus PU 32 and H. influenzae ATCC49247, but
8-fold less potent than telithromycin against constitutively resis-
tant S. pyogenes 12e206 and 128-fold less active against
S. pneumoniae 07P390. Unfortunately, azithromycin, telithromycin
and 26o are inactive against constitutively resistant S. aureus
2
.2.2. Extended antibacterial spectrum test on 26b and 26h
Because 26b and 26h showed excellent activities in the first
round of screening, we assayed their extended antibacterial profiles
against more nosocomial isolates, including ESKAPE (Enterococcus
faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter
baumannii, Pseudomonas aeruginosa and Enterobacter spp.). As

8
B.-Z. Fan et al. / European Journal of Medicinal Chemistry 193 (2020) 112222
Table 3
2.3. Bactericidal activities of azithromycin acylides
Extended antibacterial spectrum test on 26b and 26h.
Strain
Code
Phenotype
Compound, MIC
g/mL)
The bacteria that were cultured in the presence of 1 to 8-fold
MIC of the samples were transported to fresh culture medium
without adding antibacterial compounds. After incubation for the
required time, the lowest concentrations where the number of
colonies was reduced to > 3Log10 were read as MBCs (minimum
bactericidal concentrations). For details see Refs. [36]. The com-
pounds are viewed as bactericidal agents if the ratio of MBC and
MIC is less than 4. We found azithromycin acylides, exemplified by
highly potent 26j, 26l, 26b and 26o, were generally bactericidal
against S. pneumoniae and H. influenzae, but were bacteriostatic
against S. aureus and S. pyogenes (Tables 2 and 4).
(
m
LEVa
26b 26h
b
Staphylococcus epidermidis ATCC 12228
Staphylococcus epidermidis 16e5
Staphylococcus aureus
Staphylococcus aureus
Escherichia coli
MSSE
0.12
8
0.25
>64 >64
4
MRSEc
d
ATCC 29213
16e30
16e7
16e1
ATCC 2469
MSSA
0.12
32
1
8
e
MRSA
>64 >64
f
ESBLs (ꢁ)
0.5
0.5
8
8
8
64
32
64
>64
64
8
Escherichia coli
Escherichia coli
ESBLs (þ)
g
NDM-1 (þ) 16
Klebsiella Pneumoniae
Klebsiella Pneumoniae
Enterococcus faecalis
Enterococcus faecium
Acinetobacter baumannii
Enterobacter cloacae
Enterobacter aerogenes
Shigella Castellani
ATCC BAA-2146 NDM-1 (þ) >128 32
16e14
ESBLs (þ)
0.5
0.5
32
16
1
h
ATCC 29212
ATCC 700221
ATCC 19606
ATCC 43560
ATCC 13048
ATCC 12022
ATCC 27853
VSE
i
VRE
>64 >64
>64 >64
2.4. Mode of action
0.25
ꢂ0.03 32
64
64
16
0.06
ꢂ0.03
2
32
8
A molecular docking study was performed to gain insight into
the binding mode of azithromycin acylides. The crystal structure of
the large (50S) ribosomal subunit of Haloarcula marismortui
G2099A mutant in complex with azithromycin was retrieved from
the PDB ID: 1YHQ [37]. According to the procedure published
previously [32], the cladinose was removed and a pyridyl acetyl
group was attached to the oxygen at the 3-position, and then the
sidechains at the 6-position of 26o and 26l were docked in the
receptor binding site through a covalent attachment to the oxygen
at the 6-position. Only residues within 30 Å of the azithromycin
moiety were kept to simplify the calculation. Each sidechain was
docked twenty times and the best docking solutions were chosen as
the proposed molecular models, which are depicted in Figs. 3 and 4.
Due to constitutive methylation on A2058, the resistant bacteria
decrease the binding affinity of macrolides, which are easily flushed
away when nascent peptides pass by. To compensate for the
decreased binding affinity, additional interactions, such as
Pseudomonas aeruginosa
>64 >64
a
LEV: levofloxacin.
b
MSSE: methicillin-susceptible Staphylococcus epidermidis.
MRSE: methicillin-resistant Staphylococcus epidermidis.
MSSA: methicillin-susceptible Staphylococcus aureus.
MRSA: methicillin-resistant Staphylococcus aureus.
ESBLs: extended spectrum
NDM-1: new Delhi-metallo-
c
d
e
f
b-lactamases.
g
h
i
b-lactamase-1.
VSE: vancomycin-susceptible Enterococcus faecalis.
VRE: vancomycin-resistant Enterococcus faecium.
1
2
5B196. Among the hybrids of macrolides and quinolones (26p, 26r,
6s, 26t, 26u, 26w), the favorable effects of the alkyl groups at N-1
of the quinolones on activities ranked as follows: Et > Me > cyclo-Pr
26r vs 26s vs In addition, we also intended to design the analogs of
6j, (i.e. 26k, 26l, 26m, 26n with a piperazine ring) due to its
enhanced activities against constitutively resistant S. aureus 15B196
and H. influenzae ATCC49247 (Table 4). Similar to 26j, 26l had an
MIC of 8
an MIC of 0.5
6l was just 4-fold less potent than ciprofloxacin, while the pre-
(
2
hydrogen bonding and p-p interactions, are expected to be formed
between bacterial ribosomal RNA and drug molecules [38]. It was
reported that the cladinose and 3-keto have no interaction with the
bases in the NPET [13,38] but the pyridine located at the end of the
sidechain at the 3-position interacted with the ribosomal base
G2540 (G2505Ec), as shown in Figs. 3 and 4. Similar interaction
modes were reported previously in 14-membered acylides [33,39].
In addition to this interaction, the quinoline located at the end of
the sidechain at the 6-position of 26o formed hydrogen bonds to
m
g/mL against constitutively resistant S. aureus 15B196 and
m
g/mL against H. influenzae ATCC49247. Significantly,
2
viously reported macrolone shown in Fig. 2 had 16 fold weaker
activities than ciprofloxacin against constitutively resistant
S. aureus [28]. But other hybrids of macrolides and quinolones such
as 26k, 26m and 26n were not endowed with activities as high as
G2540 (G2505Ec), and the quinoline ring also forms
interaction with U2645 (U2610Ec). The quinolone located at the
end of the sidechain at 6-position of 26l formed interactions
p-p stacking
2
6l, which suggested that conversion of the 3-carboxylic acid to an
amide or conversion of the cyclopropyl group at N-1 to an ethyl
group compromised the potencies against constitutively resistant
S. aureus and H. influenzae.
p-p
with U2621 (U2586Ec). These proposed additional interactions are
expected to increase the affinities of 26o and 26l to the ribosomes
of resistant bacteria, which in turn should improve their activities
against constitutively resistant S. pneumoniae and S. pyogenes
compared to the parent drug azithromycin. However, the MICs of
26o and 26l were still fairly high against some of the isolates
compared to telithromycin and ciprofloxacin.
2
.2.4. Variation of substitutions at the 3-, 11-/12- positions of
azithromycin
The activities were basically maintained when the 2-
Although both of the tested S. aureus strains are MRSA (Table 1),
pyridylacetyl group at the 3-OH was replaced with 3-pyridyl
acetyl group (29r vs 31r; 29w vs 31w), as shown in Table 4. Cyclic
carbonylation of 11,12-OH (26k vs 29k; 26r vs 29r; 26w vs 29w)
increased MIC values of the resulting compounds by 2 to 16-fold in
treatment of susceptible and efflux-mediated S. pneumoniae and
H. influenzae, but it conferred beneficial effects against constitu-
tively resistant S. pyogenes 12e206, S. pneumoniae 07P390, S. aureus
ciprofloxacin is potent against constitutively MLS
S. aureus 15B196 but inactive against inducibly MLS
S. aureus PU 32. The resistance of PU 32 to ciprofloxacin is probably
due to the presence of mutations of the ciprofloxacin target.
Coincidently, quinolone-containing 26l, contrary to quinoline-
B
-resistant
-resistant
B
containing 26o, had
a significantly lower MIC against the
quinolone-susceptible S. aureus 15B196 but a higher MIC against
the quinolone-resistant S. aureus PU 32 (Table 4), which is distinct
from the nature of the known macrolones [26]. Moreover, the same
trend was observed in quinolone-containing 26j vs quinoline-
containing 26b (Table 2). To clearly describe this trend, we
1
5B196 and S. aureus PU 32. Conversion of the 3-carboxylic acid to a
-carboxamide in the quinolones is unfavorable for the antibacte-
rial activities of the macrolones with uncyclized 11,12-OH (26r vs
6w; 26k vs 26j), but the unfavorable effects could be counteracted
by cyclic carbonylation at 11,12-OH (31r vs 31w; 29r vs 29w).
3
2
compared antibacterial activity (in the units of mM) of quinoline-

B.-Z. Fan et al. / European Journal of Medicinal Chemistry 193 (2020) 112222
9
Table 4
Antibacterial activity of 26k - 26u, 26w, 29j, 29k, 29r, 29w, 31r and 31w against erythromycin-susceptible and -resistant pathogens.
Compound
MIC and MBC (
mg/mL)
S. pneumoniae ATCC 49619
S. pneumoniae PU 09 efflux
S. pneumoniae 07P390 constitutive
a
MLS
B
MIC
MBC
MBC/MIC
MIC
MBC
MBC/MIC
MIC
MBC
MBC/MIC
CAMb
e
e
e
e
e
e
e
8
0.5
2
e
e
e
e
e
e
>256
0.25
2
e
e
e
e
e
e
c
TEL
0.03
2
d
CFX
26 series
2
2
2
2
6k
0.25
0.5
0.5
1
2
2
2
2
4
2
4
2
4
8
8
4
1
4
2
2
128
8
128
8
1
1
2
2
6l
6m
6n
0.5
1
64
64
128
128
0.5
1
2
2
6o
6p
0.03
0.25
0.03
0.25
1
1
0.5
2
1
4
2
2
32
64
2
256
>256
e
2
2
6q
6r
0.25
0.5
0.25
0.5
1
1
2
4
4
4
2
1
128
256
>256
>256
e
e
26s
0.12
0.5
4
2
2
1
256
>256
e
2
2
6t
0.25
0.5
0.5
1
2
2
2
4
4
8
2
2
256
256
>256
e
e
6u
256
(
continued on next page)

10
B.-Z. Fan et al. / European Journal of Medicinal Chemistry 193 (2020) 112222
Table 4 (continued )
Compound
MIC and MBC (mg/mL)
S. pneumoniae ATCC 49619
S. pneumoniae PU 09 efflux
S. pneumoniae 07P390 constitutive
a
MLS
MIC
64
B
MIC
0.25
MBC
0.5
MBC/MIC
2
MIC
2
MBC
4
MBC/MIC
2
MBC
256
MBC/MIC
4
2
2
6w
9 series
2
2
2
9j
4
16
8
4
2
2
4
8
4
16
16
8
4
2
2
>256
32
>256
32
e
1
9k
9r
4
0.5
1
64
128
2
2
3
9w
1
1
1
4
8
2
64
64
1
1 series
3
3
1r
1
2
2
8
2
4
4
4
8
2
4
64
64
128
128
2
2
1w
16
Compound
MIC and MBC (mg/mL)
S. aureus PU 32 MRSAe,
inducible MLS
S. aureus 15B196 MRSA,
constitutive MLS
H. influenzae ATCC 49247
S. pyogenes 12e206
constitutive MLS
B
B
B
MIC
MBC
MBC/MIC
MIC
MBC
MBC/MIC
MIC
MBC
MBC/MIC
MIC
MBC
MBC/MIC
CAM
TEL
CFX
64
2
256
e
e
e
e
e
e
>256
>256
2
e
e
e
e
e
e
16
4
0.004
e
e
e
e
e
e
>256
0.25
0.5
e
e
e
e
e
e

B.-Z. Fan et al. / European Journal of Medicinal Chemistry 193 (2020) 112222
11
Table 4 (continued )
Compound
MIC and MBC (
mg/mL)
S. aureus PU 32 MRSAe,
S. aureus 15B196 MRSA,
constitutive MLS
H. influenzae ATCC 49247
S. pyogenes 12e206
constitutive MLS
inducible MLS
B
B
B
MIC
MBC
MBC/MIC
MIC
MBC
MBC/MIC
MIC
MBC
MBC/MIC
MIC
MBC
MBC/MIC
26 series
2
2
2
2
6k
128
128
128
32
>256
>256
>256
>256
e
>256
>256
e
1
64
0.5
4
128
0.5
4
2
1
1
1
16
8
128
8
6l
e
8
8
>64
128
>8
8
6m
6n
e
128
256
128
>256
e
e
16
16
>8
8
8
>128
>8
2
2
6o
6p
4
>32
>8
>8
>256
>256
>256
>256
e
e
4
8
2
2
2
2
>16
>16
>8
>8
16
>128
64
128
2
2
6q
6r
16
>128
>256
>8
>256
>256
>256
>256
e
e
64
64
128
64
2
1
4
>32
>8
128
e
32
128
4
26s
32
>256
>8
>256
>256
e
16
16
1
8
>64
>8
2
2
6t
16
>128
>256
>8
>256
>256
>256
>256
e
e
32
64
64
2
2
8
>64
>8
6u
>256
e
128
32
128
4
26w
128
>256
e
>256
>256
e
32
64
2
16
128
8
(
continued on next page)

12
B.-Z. Fan et al. / European Journal of Medicinal Chemistry 193 (2020) 112222
Table 4 (continued )
Compound
MIC and MBC (mg/mL)
S. aureus PU 32 MRSAe,
S. aureus 15B196 MRSA,
constitutive MLS
H. influenzae ATCC 49247
S. pyogenes 12e206
constitutive MLS
inducible MLS
B
B
B
MIC
MBC
MBC/MIC
MIC
MBC
MBC/MIC
MIC
MBC
MBC/MIC
MIC
MBC
MBC/MIC
29 series
2
2
2
9j
>256
32
>256
>256
>256
e
>256
32
>256
>256
>256
e
8
16
2
64
16
16
>256
16
>8
1
9k
9r
>8
>4
>8
e
>256
64
>256
128
e
2
64
128
64
4
29w
64
>256
>4
>256
>256
e
64
128
2
32
64
2
31 series
3
3
1r
64
>256
>256
>4
>256
>256
>256
e
e
64
32
64
64
1
2
32
64
64
64
2
1
1w
128
e
256
a
b
c
B
MLS : macrolide-lincosamide-streptogramin B.
CAM: clarithromycin.
TEL: telithromycin.
CFX: ciprofloxacin.
d
e
MRSA: methicillin-resistant Staphylococcus aureus.
and quinolone-containing compounds vs ciprofloxacin (Table 5).
Quinolone-containing azithromycin derivatives (26j and 26l)
showed higher activity than quinoline-containing azithromycin
derivatives (26b and 26o) against ciprofloxacin-susceptible strains.
However, quinolone-containing azithromycin derivatives (26j and
moiety, for example, conversion of either the featuring 3-carboxylic
acid to an amide (26j vs 26k) or the favorable cyclopropyl group at
N-1 to an ethyl group (26j, 26l vs 26m, 26n), significantly decreased
B
the potencies against constitutively MLS -resistant but quinolone-
susceptible S. aureus. Therefore, the whole cell-based SAR strongly
suggest that the hybrids of quinolone and macrolide reported
herein may possess an additional quinolone-associated antibacte-
rial mechanism, which is often referred to as topoisomerase
poisoning. In other words, the formation of a topoisomerase-drug-
DNA ternary complex would lead to inhibition of DNA replication,
2
6l) showed weaker activity than quinoline-containing azi-
thromycin derivatives (26b and 26o) against ciprofloxacin-resistant
strains. Among them, 26l showed the minimum variation against
the strains of S. aureus listed in Table 5. Further SAR studies also
revealed that alteration of the fluoroquinolones’ pharmacophore

B.-Z. Fan et al. / European Journal of Medicinal Chemistry 193 (2020) 112222
13
Chart 1. Substructures of the amines for the target compounds 26, 29 and 31.
generation of double-strand breaks and subsequent cell death [40].
For this reason, we decided to examine whether 26j and 26l are
quinolone-like DNA gyrase-targeting agents (Fig. 5). The DNA
negative supercoiling assay with E. coli gyrase indicated IC50 values
quinolones were documented [9,15e23,34], a systematic study
clearly indicated none of the hybrids possess the quinolones’ mode
of action [22,26]. Therefore, the macrolones presented here are
different from previous macrolones and possess a novel mode of
action.
of macrolones 26j and 26l, in contrast to 0.44
mM of ciprofloxacin
[
41], are 44.1 ± 3.2 M and 9.6 ± 0.2 M, respectively (Table 6).
m
m
Gyrase poisoning involves formation of a stable DNA-gyrase-drug
complex containing a double-stranded DNA break. This could be
proven by a DNA cleavage gel assay. The assay showed that 26l
generated linear DNA at lower concentration than 26j, as illustrated
in Fig. 5. Thus, 26l appeared to be more effective in poisoning DNA
gyrase than 26j (Table 6), which is consistent with the order of their
bactericidal effects (Tables 2 and 4). In any case, these results
demonstrated that both 26j and 26l could in fact target and poison
DNA gyrase. Since the hybrids are weaker inhibitors than cipro-
floxacin, the gyrase poisoning probably contribute only modestly to
the overall activity of the hybrids. The MIC data of ciprofloxacin, 26j
and 26l against E coli whole cells (E coli BW25113, JW5503-1 and
JW5503-KanS) are consistent with IC50 values and poisoning effects
against E coli DNA gyrase (Table 6). Molecules containing typical
acid (carboxylic) and good base (pyridine, piperazine, secondary
amine of the linker etc.) together within the scaffold of azi-
thromycin can vary in the form of zwitterions in solution. According
to the logP and pKa values calculated by using ChemDraw, com-
pounds 26j and 26l probably existed in the cation form at pH ¼ 7.4
and would be more hydrophilic because of their lower logD values
than parent compounds azithromycin and ciprofloxacin (Table 6).
Despite the fact that a number of hybrids of macrolides and
3
. Conclusion
We designed and synthesized twenty-eight new quinolone/
quinoline-containing azithromycin acylides, and most of them
showed superior activities over parent azithromycin against clini-
cally isolated pathogens carrying a variety of resistant genotypes
and phenotypes.
The whole cell-based SAR studies centered on the 6-position of
azithromycin in addition to the 3- and 11-/12-positions. Molecular
docking suggested the aryl groups appended on the 3- and 6-
positions have interactions with bacterial ribosomal RNA bases.
Introduction of quinolines through an optimized rigid linker
attached to 6-OH azithromycin acylides resulted in compounds,
such as 26o, that exhibited comparable activities to the marketed
drug telithromycin against susceptible S. pneumoniae, efflux-
mediated S. pneumoniae, inducibly resistant erm-encoded
S. aureus and H. influenzae. Meanwhile, 26o showed reduced MICs
over the parent drug azithromycin against constitutively resistant
S. pneumoniae and S. pyogenes but not against constitutively resis-
tant S. aureus.
Thus far, hybrids of macrolides and quinolones did not inhibit
growth of pathogens in a way similar to fluoroquinolones. However,

14
B.-Z. Fan et al. / European Journal of Medicinal Chemistry 193 (2020) 112222
macrolides (MICs of telithromycin, azithromycin and clari-
thromycin, >256 g/mL). Considering the fact that the molecular
m
weight of 26l is 3-fold more than that of ciprofloxacin, the activity
of 26l actually reached that of an equimolar concentration of cip-
rofloxacin against constitutively resistant S. aureus (MICs: 7
mmol/L
of 26l vs 6 mol/L of ciprofloxacin). This novel mode of action shed
m
light on how to rationally design novel macrolides capable of
addressing constitutively resistant S. aureus in the future.
4. Experimental section
4.1. DNA supercoiling assay
E. coli DNA gyrase was purchased from New England Biolabs
(Ipswich, MA, USA). The activity of DNA gyrase was measured un-
der the reaction conditions described below and one unit was
defined as the amount of DNA gyrase required to completely su-
ꢀ
percoil 0.3
m
g of the relaxed DNA at 37 C in 15 min. The relaxed
DNA, used as the substrate in the supercoiling assay, was prepared
by incubating negatively supercoiled pBR322 DNA with E. coli
topoisomerase I.
The supercoiling and DNA cleavage assays were performed as
described previously [41,42]. Briefly, supercoiling reaction mixtures
ꢀ
(20
m
L) containing 50 mM Tris-HCl (pH 8.0 at 23 C), 10 mM MgCl
2
,
100 mM potassium glutamate, 10 mM dithiothreitol, 50
mg/mL
bovine serum albumin, 1 mM ATP, 0.3 g of the relaxed DNA, 1 unit
m
of E. coli gyrase, and the various concentrations of either 26j or 26l
ꢀ
were incubated at 37 C for 15 min. Ciprofloxacin was used as a
control gyrase inhibitor. Reactions were terminated by adding
ꢀ
EDTA to 25 mM and further incubating at 37 C for 5 min. The DNA
products were analyzed by electrophoresis through vertical 1.2%
agarose gels (14 x 10 ꢃ 0.3 cm) at 2 V/cm for 15 h in a running buffer
ꢀ
of 50 mM Tris-HCl (pH 7.9 at 23 C), 40 mM sodium acetate, and
1
mM EDTA (TAE buffer). Gels were stained with 0.5 mg/mL
ethidium bromide, and then photographed and quantified using a
MyECL Imager [Thermo Fisher Scientific (Waltham, MA, USA)].
4.2. DNA cleavage assay
The DNA negative supercoiling and DNA cleavage assays were
performed as described previously [41,42]. Briefly, DNA cleavage
reaction mixtures (20
m
L) containing 50 mM Tris-HCl (pH 8.0 at
g/mL bovine serum
g of the supercoiled pBR322
ꢀ
23 C), 10 mM MgCl
2
, 10 mM dithiothreitol, 50
g/mL tRNA, 0.3
m
albumin,1 mM ATP, 5
m
m
DNA, 10 units of E. coli gyrase, and the various concentrations of
ꢀ
either 26j or 26l were incubated at 37 C for 15 min. SDS was added
Fig. 3. Molecular model of compound 26o (green) based on the crystal structure of the
complex of azithromycin and G2099A mutant Haloarcula marismortui (PDB ID: 1YHQ).
a) The pyridine located at the end of the sidechain at the 3-position interacts with
G2540 (G2505Ec). b) The quinoline located at the end of the sidechain at the 6-position
to a concentration of 1%, and the reaction mixtures were further
incubated at 37 C for 5 min. EDTA and proteinase K were then
g/mL, respectively, and incubation was
continued for an additional 30 min at 37 C. The DNA products were
ꢀ
added to 25 mM and 100
m
hydrogen bonds to G2540 (G2505Ec), and the quinoline ring also forms
p-
p
stacking
ꢀ
interaction with U2645 (U2610Ec). (For interpretation of the references to colour in
this figure legend, the reader is referred to the Web version of this article.)
purified by extraction with phenol/chloroform/isoamyl alcohol
(
25:24:1, v/v) and then analyzed by electrophoresis through ver-
tical 1.2% agarose gels at 2 V/cm for 15 h in TAE buffer that con-
tained 0.5 g/mL ethidium bromide. After destaining in water, gels
were photographed and quantified using a MyECL Imager.
m
we found that macrolones with a spacer from the 6-position of
azithromycin to the 7-position of quinolones could possess a
quinolone-associated mode of action, which was corroborated by
the observation of their high MIC values against quinolone-
resistant strains. The DNA supercoiling assay and the DNA cleav-
age assay revealed that 26j and 26l could poison E. coli DNA gyrase,
although their IC50 values were higher than that of ciprofloxacin.
We assume that dual modes of action, namely inhibition of protein
synthesis plus poisoning of DNA gyrase and/or topoisomerase IV,
may contribute to the enhanced activities of 26j and 26l against
S. aureus that is constitutively resistant to all of the marketed
4.3. Synthetic procedures
All reagents and solvents were purchased from commercially
available sources and used without further purification. The prog-
ress of reactions was monitored by TLC (thin-layer chromatog-
raphy) through pre-coated silica gel HSGF254 plates (0.2 mm).
Visualization was performed by iodine staining and UV light. The
purification of compounds was carried out by column chromatog-
raphy with silica gel (100e200 or 200e300 mesh) with various

B.-Z. Fan et al. / European Journal of Medicinal Chemistry 193 (2020) 112222
15
Table 5
The ratio values of MIC (
m
mol/L) of quinoline-containing (26b and 26o) and quinolone-containing (26j and 26l) series vs ciprofloxacin, which was normalized to 1.
The fold numbers of antibacterial activity relative to ciprofloxacin
Compound
S. aureus PU 32
MRSA , inducible MLS
S. aureus 15B196
MRSA, constitutive MLS
H. influenzae ATCC 49247
Azithromycin-susceptible
a
b
B
B
Ciprofloxacin-resistant
Ciprofloxacin-susceptible
Ciprofloxacin-susceptible
Azithromycin
Clarithromycin
Telithromycin
0.22
0.11
>226
>57
>52
88
>44
9.7
221
1768
407
172
344
19
0.0032
0.0054
0.0054
0.076
0.14
2
2
2
2
6b
6o
6j
6l
1.2
36
a
MRSA: methicillin-resistant Staphylococcus aureus.
MLS : macrolide-lincosamide-streptogramin B.
B
b
1
eluent systems. Infrared spectra were recorded on KBr pellets using
Nicolet iS5 FT-IR spectrometer. H, C NMR and COSY spectra were
recorded on Bruker Ascend 400 MHz, ARX 500 MHz and Ascend
202.0869, calcd for C12
: 7.83 (d, J ¼ 3.0 Hz, 2 H, HeAr), 7.71 (d, J ¼ 3.3 Hz, 2 H, HeAr),
5.85e5.74 (m, 1 H, -CH¼CH ), 5.10e4.99 (m, 2 H, -CH¼CH ), 3.77
(td, J ¼ 2.0 Hz, 2 H, -N-CH -), 2.45 (q, J ¼ 7.3 Hz, 2 H, -N-
¼7.1 Hz, J
CH CH -).
2 3
H12NO 202.0863. H NMR (CDCl , 400 MHz)
1
13
d
2
2
7
00 MHz spectrometers using CDCl
vents, and TMS (tetramethylsilane) as internal standard. The HRMS
high resolution mass spectra) were recorded on Agilent Q-TOF
520 LC-MS. The melting points of the target compounds were
3
, DMSO‑d
6
or CD
3
OD as sol-
1
2
2
2
2
(
6
4
.3.5. General procedures for the preparation of intermediates 6a,
measured with a SGW X-4A melting point apparatus and are un-
corrected. The high purities of the target compounds were
confirmed by high-performance TLC analysis plus verification by
NMR spectrometry (see Supporting Information).
7a, 7b and 7d-7i
To a solution of compound 2 or 3 (1.2 eq) in acetonitrile in a high
pressure vessel, CuI (0.1 eq), bis(triphenylphosphine)palladium(II)
dichloride (0.05 eq), the corresponding halogenated aryl (1 eq) and
triethylamine (1.5 eq) were added. The reaction mixture was stirred
4.3.1. 2-(Prop-2-yn-1-yl)isoindolin-1,3-dione (2)
ꢀ
at 80 C for 4 h under Ar. Water was added and the resulting
Compound 1 (1.71 g, 11.6 mmol) was suspended in EtOH (20 mL)
mixture was extracted with EtOAc. The organic layer was washed
with water and brine, and concentrated by evaporation. The residue
was dissolved with EtOAc and treated with petroleum ether. The
product was precipitated and filtered to yield the compounds 6a,
and KOH (0.650 g, 11.6 mmol) was added. The mixture was stirred
at room temperature for 2 h, and evaporated to remove EtOH. The
residue was dissolved in anhydrous DMF (15 mL) and propargyl
bromide (1.10 mL, 12.8 mmol) was added. The mixture was stirred
at reflux for 72 h. The resulting solution was cooled, diluted with
7a, 7b and 7d-7i.
3
EtOAc and partitioned with saturated NaHCO . The organic phase
4
.3.5.1. 2-[3-(Quinolin-3-yl)prop-2-yn-1-yl]isoindolin-1,3-dione
was washed with water and brine. The solvent was removed by
rotary evaporation. The residue was treated with MeOH, and the
suspension was filtered to provide compound 2 (1.25 g, 6.75 mmol,
(6a). Compound 6a (0.660 g, 2.11 mmol, 62.2%) was prepared
starting from compound (0.630 g, 3.39 mmol) and 3-
bromoquinoline (0.920 mL, 6.78 mmol) according to the general
procedure.
2
5
8.1%) as a white solid.
4.3.2. 2-(But-3-yn-1-yl)isoindolin-1,3-dione (3)
To a suspension of compound 1 (5.00 g, 34.0 mmol) in toluene
4.3.5.2. 2-[4-(Quinolin-3-yl)but-3-yn-1-yl]isoindolin-1,3-dione (7a).
Compound 7a (0.500 g, 1.53 mmol, 56.8%) was prepared starting
from compound 3 (0.500 g, 2.70 mmol) and 3-bromoquinoline
(0.730 mL, 5.40 mmol) according to the general procedure.
(
3
60 mL), but-3-yn-1-ol (2.83 mL, 37.4 mmol), PPh
3
(9.81 g,
7.4 mmol), DIAD (8.03 mL, 40.8 mmol) were added. The reaction
ꢀ
mixture was stirred at 0 C for 10 min, and then at room temper-
ature for 1 h. After addition of MeOH (20 mL), the mixture was
stirred for another 30 min. The resulting suspension was filtered
and washed with MeOH. The filtrate was concentrated via rotary
evaporation and the residue was treated with MeOH. The precipi-
tate was collected by filtration to afford compound 3 (5.85 g, 86.4%)
as a white solid.
4.3.5.3. 2-[4-(Quinolin-6-yl)but-3-yn-1-yl]isoindolin-1,3-dione (7b).
Compound 7b (0.570 g, 1.75 mmol, 78.8%) was prepared starting
from compound 3 (0.440 g, 2.22 mmol) and 6-bromoquinoline
(0.300 mL, 2.22 mmol) according to the general procedure.
4
(
.3.5.4. 5-(4-(1,3-Dioxoisoindolin-2-yl)but-1-yn-1-yl)nicotinamide
7d). Compound 7d (0.481 g, 1.51 mmol, 75.5%) was prepared
starting from compound (0.440 g, 2.20 mmol) and 5-
bromonicotinamide (0.400 g, 2.00 mmol) according to the gen-
eral procedure.
4
.3.3. 2-Allylisoindolin-1,3-dione (4)
Compound 4 (1.81 g, 9.67 mmol, 83.7%) was prepared starting
3
from compound 1 (1.70 g, 11.6 mmol) and allyl bromide (1.10 mL,
2.7 mmol) according to the procedure used to prepare compound
1
2
.
4
.3.4. 2-(But-3-en-1-yl)isoindolin-1,3-dione (5)
Compound 5 (1.90 g, 9.44 mmol, 95.8%) was prepared starting
4.3.5.5. 1-Cyclopropyl-6-(4-(1,3-dioxoisoindolin-2-yl)but-1-yn-1-
yl)-4-oxo-1,4-dihydroquinoline-3-carboxamide (7e). Compound 7e
(0.540 g, 1.27 mmol, 63.5%) was prepared starting from compound
3 (0.600 g, 3.00 mmol) and 1-cyclopropyl-6-iodo-4-oxo-1,4-
dihydroquinoline-3-carboxamide (0.710 g, 2.00 mmol) according
to the general procedure.
from compound 1 (2.20 g, 14.9 mmol) and 4-bromo-1-butene
1.00 mL, 9.85 mmol) according to the procedure used to prepare
(
compound 2, and purified by silica gel column chromatography
(
petroleum ether/EtOAc ¼ 12:1). HRMS (ESI) (M þ H)þ m/z

16
B.-Z. Fan et al. / European Journal of Medicinal Chemistry 193 (2020) 112222
dihydroquinoline-3-carboxamide (0.500 g, 1.52 mmol) according
to the general procedure.
4
.3.5.8. 1-Cyclopropyl-6-(4-(1,3-dioxoisoindolin-2-yl)but-1-yn-1-
yl)-N-methyl-4-oxo-1,4-dihydroquinoline-3-carboxamide (7h).
Compound 7h (0.370 g, 0.840 mmol, 86.6%) was prepared starting
from compound 3 (0.190 g, 0.970 mmol) and 1-cyclopropyl-6-iodo-
N-methyl-4-oxo-1,4-dihydroquinoline-3-carboxamide (0.360 g,
0.970 mmol) according to the general procedure.
4
1
.3.5.9. Ethyl 1-cyclopropyl-6-(4-(1,3-dioxoisoindolin-2-yl)but-1-yn-
-yl)-4-oxo-1,4-dihydroquinoline-3-carboxylate (7i). Compound 7i
(
(
0.740 g,1.63 mmol, 81.5%) was prepared starting from compound 3
0.480 g, 2.40 mmol) and ethyl 1-cyclopropyl-6-iodo-4-oxo-1,4-
dihydroquinoline-3-carboxylate (0.770 g, 2.00 mmol) according
to the general procedure.
4
.3.6. General procedures for the preparation of intermediates 7c
and 7j
To a mixture of acetonitrile/trimethylamine (1: 1), CuI (0.1 eq)
and corresponding halogenated aryl (1 eq) were added. The
mixture was stirred 20 min at room temperature. Compound 3 (1.2
eq) and bis(triphenylphosphine)palladium(II) dichloride (0.05 eq)
were added to the reaction mixture. The reaction mixture was
ꢀ
stirred at 50 C for 24 h under Ar. The reaction was quenched with
water. The resulting mixture was extracted with EtOAc. The organic
layer was washed with water and brine, and evaporated to remove
the solvent. The residue was dissolved with EtOAc and treated with
petroleum ether. The product was precipitated and filtered to
provide compounds 7c and 7j.
4
.3.6.1. 2-(4-(4-Oxo-1,4-dihydroquinolin-6-yl)but-3-yn-1-yl)iso-
indoline-1,3-dione (7c). Compound 7c (0.510 g, 1.50 mmol, 90.7%)
was prepared starting from compound 3 (0.400 g, 1.99 mmol) and
6-iodoquinolin-4-ol (0.450 g, 1.66 mmol) according to the general
procedure.
4
.3.6.2. 1-Cyclopropyl-6-(4-(1,3-dioxoisoindolin-2-yl)but-1-yn-1-
yl)-4-oxo-1,4-dihydroquinoline-3-carboxylic acid (7j).
Compound 7j (0.290 g, 0.680 mmol, 48.2%) was prepared starting
from compound 3 (0.340 g, 1.70 mmol) and 1-cyclopropyl-6-iodo-
4-oxo-1,4-dihydroquinoline-3-carboxylic acid (0.500 g, 1.41 mmol)
according to the general procedure.
4
.3.7. General procedures for the preparation of intermediates 8a
and 9a
To a mixture of compound 4 or 5 (1 eq) and 3-bromoquinoline (2
eq) in acetonitrile, Pd(OAc) (0.3 eq), tri-o-tolylphosphine (0.6 eq)
and triethylamine (3 eq) were added. The vessel was recharged
Fig. 4. Molecular model of compound 26l (green) based on the crystal structure of the
complex of azithromycin and G2099A mutant Haloarcula marismortui (PDB ID: 1YHQ).
a) The pyridine located at the end of the sidechain at the 3-position interacts with
G2540 (G2505Ec). b) The quinolone located at the end of the sidechain at the 6-
2
ꢀ
ꢀ
with Ar. The mixture was stirred at 60 C for 1 h, and then at 90 C
for another 24 h. Water was added and the mixture was extracted
with EtOAc. The organic layer was washed with water and brine,
and evaporated to remove the solvent. The resulting mixture was
dissolved with EtOAc, treated with petroleum ether, and filtered to
collect the products 8a and 9a.
position
p-p interacts with U2621 (U2586Ec).
4
.3.5.6. 6-(4-(1,3-Dioxoisoindolin-2-yl)but-1-yn-1-yl)-1-ethyl-4-
oxo-1,4-dihydroquinoline-3-carboxamide (7f). Compound 7f
0.460 g, 1.11 mmol, 76.0%) was prepared starting from compound 3
0.350 g, 1.75 mmol) and 1-ethyl-6-iodo-4-oxo-1,4-
(
(
4.3.7.1. 2-(3-(Quinolin-3-yl)allyl)isoindoline-1,3-dione
(8a).
Compound 8a (1.05 g, 3.34 mmol, 58.7%) was prepared starting
dihydroquinoline-3-carboxamide (0.500 g, 1.46 mmol) according
to the general procedure.
from compound 4 (1.06 g, 5.69 mmol) according to the general
þ
procedure. HRMS (ESI) (M þ H) m/z 315.1123, calcd for C20
15 2 2
H N O
315.1128.
4
.3.5.7. 6-(4-(1,3-Dioxoisoindolin-2-yl)but-1-yn-1-yl)-1-methyl-4-
oxo-1,4-dihydroquinoline-3-carboxamide (7g). Compound 7g
0.450 g, 1.21 mmol, 79.6%) was prepared starting from compound
4.3.7.2. 2-[4-(Quinolin-3-yl)but-3-en-1-yl]isoindolin-1,3-dione (9a).
Compound 9a (0.370 g, 1.13 mmol, 45.6%) was prepared starting
from compound 5 (0.500 g, 2.48 mmol) according to the general
(
3
(0.360 g, 1.82 mmol) and 6-iodo-1-methyl-4-oxo-1,4-

B.-Z. Fan et al. / European Journal of Medicinal Chemistry 193 (2020) 112222
17
Fig. 5. Activities of 26j and 26l against E. coli DNA gyrase. Examples of the results of the DNA supercoiling assay (A) and DNA cleavage assays (B and C) are shown here. Ciprofloxacin
CFX) was used as a positive control.
(
Table 6
Activities of 26j and 26l against E. coli DNA gyrase and E. coli whole cells.
Catalytic inhibitiona
Poisoning effect
Maximumb
MIC (mg/mL)
clogD (pH ¼ 7.4)
e
Compound
Relativec
E. coli BW25113
E. coli JW5503-1d
E. coli JW5503-KanSd
Ciprofloxacin
0.44 ± 0.008f
44.1 ± 3.2
9.6 ± 0.2
e
1.2 ± 0.1
69.5 ± 6.8
18.2 ± 2.6
e
100
28
71
e
8
4
2
>16
ꢂ0.064
ꢂ0.064
ꢁ1.7
ꢁ6.3
ꢁ5.8
1.4
2
2
6j
6l
1
1
0.5
4
0.5
2
azithromycin
a
The IC50 values (the 50% inhibitory concentration, mM) against DNA gyrase were determined in the supercoiling assay. An example of the result of the supercoiling assay
are shown in Fig. 5A.
b
The concentrations (mM) required to generate the maximum level of linear DNA were determined in the DNA cleavage assay. An example of the result of the DNA cleavage
assay are shown in Fig. 5B.
c
The level of linear DNA generated by 10 mM 26j or 26l was normalized to the level of linear DNA generated by 1 mM ciprofloxacin (%). An example of the result of the DNA
cleavage assay are shown in Fig. 5C.
d
E. coli BW25113 DtolC (depletion of tolC efflux genes).
e
f
logD z logP þ (pH e pKa), where logP and pKa were calculated by using ChemDraw (Version 16.0.1.4).
Data from references [41].
procedure.
2 2
the solvent. The residue was dissolved with CH Cl , washed with
water and brine, concentrated to afford 2-(3-(quinolin-3-yl)propyl)
isoindoline-1,3-dione (or 2-(4-(quinolin-3-yl)butyl)isoindoline-
1,3-dione). The hydrogenolysis product was used directly for the
Gabriel reaction to yield primary amines without further
purification.
4
.3.8. General Gabriel reaction procedures for the preparation of
amines 10a, 11a-11i, 12a, 13a, 14a and 15a
Compound 8a (or 9a) (1 eq) was dissolved in MeOH. 10% Pd/C,
HCOOH (16 eq) and ammonium formate (8 eq) were added. The
mixture was stirred at room temperature overnight. The insoluble
material was filtered off, and the filtrate was evaporated to remove
The corresponding sidechains capped with phthalimide 6a (or
7a - 7j, 8a, 9a, hydrogenation products of 8a and 9a) (1 eq) was

18
B.-Z. Fan et al. / European Journal of Medicinal Chemistry 193 (2020) 112222
dissolved in EtOH and 80% hydrazine hydrate (2 eq) was added. The
mixture was stirred at reflux for 2 h. The resulting mixture was
cooled to room temperature, and an insoluble solid was observed.
The solid was filtered off and washed with EtOH. The filtrate was
evaporated to remove the solvent. The residue was dissolved with
procedure, and purified by silica gel column chromatography
(CH
2
Cl
2
/MeOH/NH
3
‧H
2
O ¼ 10:1:0.1). IR (KBr)
n
: 3440, 2973, 2844,
ꢁ1
þ
1593, 1364, 1055, 1033 cm . HRMS (ESI) (M þ H) m/z 190.0969,
1
calcd for C10
H
12
N
3
O 190.0975. H NMR (DMSO‑d
6
, 400 MHz)
d: 8.97
0
0
(d, J ¼ 2.1 Hz, 1 H, 6 -pyridyl), 8.76 (d, J ¼ 2.0 Hz, 1 H, 2 -pyridyl),
0
CH
dried over anhydrous MgSO
ration to afford compounds 10a, 11a-11i, 12a, 13a, 14a, 15a.
2
Cl
2
, and washed with water and brine. The organic layer was
8.30 (d, J ¼ 2.1 Hz,1 H, 4 -pyridyl), 8.24 (s,1 H, -CO-NH
2
), 7.68 (s,1 H,
4
, filtered and concentrated by evapo-
-CO-NH
NH eCH
DMSO‑d
78.7, 20.9.
2
), 5.94e4.84 (br, 2 H, -NH
-), 2.72 (t, J ¼ 6.8 Hz, 2 H, NH
, 100 MHz) : 166.1, 154.2, 148.0, 138.0, 129.7, 120.0, 92.2,
2
), 2.93 (t, J ¼ 6.9 Hz, 2 H,
13
2
2
2 2 2
eCH CH -). C NMR
(
6
d
4.3.8.1. 3-(Quinolin-3-yl)prop-2-yn-1-amine (10a). Compound 10a
was prepared starting from compound 6a according to the general
procedure, and used directly for the next step without further
4.3.8.6. 6-(4-Aminobut-1-yn-1-yl)-1-cyclopropyl-4-oxo-1,4-
dihydroquinoline-3-carboxamide (11e). Compound 11e (0.200 g,
0.680 mmol, 26.2%) was prepared starting from compound 7e
(1.10 g, 2.59 mmol) according to the general procedure, and purified
purification. IR (KBr)
n
: 3323, 2870, 2643, 2078, 1492, 1386, 913,
ꢁ
1
þ
7
C
88, 770 cm . HRMS (ESI) (M þ H) m/z 183.0904, calcd for
1
12
H
11
N
2
183.0917. H NMR (DMSO‑d
6
, 400 MHz)
d
: 9.02 (d,
0
0
J ¼ 2.2 Hz, 1 H, 2 -quinolyl), 8.71 (d, J ¼ 2.2 Hz, 1 H, 4 -quinolyl),
2 2 3
by silica gel column chromatography (CH Cl /EtOH/NH ‧
0
0
0
8
.18e8.11 (m, 2 H, 5 -quinolyl, 8 -quinolyl), 7.92 (ddd, J
1
¼ 8.6 Hz,
H
2
O ¼ 10:0.8:0.05). IR (KBr)
n
: 3452, 2975, 2359, 1651, 1592,
0
ꢁ1
þ
J
2
¼ 6.9 Hz, J
quinolyl), 6.43 (s, 2 H, -NH
DMSO‑d , 100 MHz) : 151.0, 145.1, 141.1, 132.2, 128.9, 128.7, 127.8,
3
¼ 1.5 Hz, 1 H, 6 -quinolyl), 7.74e7.72 (m, 1 H, 7 -
1052 cm . HRMS (ESI) (M þ H) m/z 296.1394, calcd for
1
3
1
0
2
), 4.09 (q, J ¼ 5.6 Hz, 2 H, -CH
2
-). C NMR
C
17
H
18
N
3
O
2
296.1394. H NMR (CD
3
OD, 400 MHz)
d
: 8.80 (s, 1 H, 2 -
0
(
6
d
quinolyl), 8.26 (d, J ¼ 2.0 Hz,1 H, 5 -quinolyl), 8.10 (d, J ¼ 8.8 Hz,1 H,
0
0
127.4, 116.0, 87.1, 82.9, 29.3.
8 -quinolyl), 7.78 (dd, J
tt, J
¼ 7.3 Hz, J
NH eCH
-), 2.65 (t, J ¼ 6.6 Hz, 2 H, NH
2 H, 2 H-cyclopropyl), 1.21e1.15 (m, 2 H, 2 H-cyclopropyl). C NMR
(DMSO‑d , 100 MHz) : 175.6, 165.7, 148.4, 141.2, 128.4, 128.0, 126.9,
1
¼ 8.8 Hz, J
2
¼ 2.1 Hz, 1 H, 7 -quinolyl), 3.69
(
1
2
¼ 4.0 Hz, 1 H, 1 H-cyclopropyl), 2.92 (s, 2 H,
4.3.8.2. 4-(Quinolin-3-yl)but-3-yn-1-amine (11a). Compound 11a
2
2
2 2 2
eCH CH -), 1.40e1.33 (m,
13
was prepared starting from compound 7a according to the general
procedure, and used directly for the next step without further
6
d
þ
purification. HRMS (ESI) (M þ H) m/z 197.1075, calcd for C13
H
13
N
2
126.4, 120.5, 111.9, 93.9, 81.1, 41.4, 35.4, 24.4, 8.0.
1
0
1
97.1073. H NMR (DMSO‑d
6
, 700 MHz)
d
: 9.19 (d, J ¼ 2.0 Hz, 1 H, 2 -
0
quinolyl), 8.87 (s, 1 H, 4 -quinolyl), 8.67e8.58 (m, 2 H, -NH
2
), 8.20
4. 3.8.7. 6-(4-Aminobut-1-yn-1-yl)-1-ethyl-4-oxo-1, 4-
dihydroquinoline-3-carboxamide (11f). Compound 11f (0.150 g,
0.530 mmol, 47.8%) was prepared starting from compound 7f
(0.460 g, 1.11 mmol) according to the general procedure, and pu-
0
0
(
d, J ¼ 8.5 Hz, 1 H, 5 -quinolyl), 8.11 (d, J ¼ 8.0 Hz, 1 H, 8 -quinolyl),
0
0
7
.93 (t, J ¼ 7.2 Hz, 1 H, 6 -quinolyl), 7.77 (t, J ¼ 7.5 Hz, 1 H, 7 -qui-
nolyl), 3.06 (q, J ¼ 6.7 Hz, 2 H, -CH
2
C≡C-), 2.96 (t, J ¼ 7.0 Hz, 2 H,
: 150.4, 142.6, 133.1,
13
NH
2
eCH
2
-). C NMR (DMSO‑d
6
, 175 MHz)
d
2 2 3
rified by silica gel column chromatography (CH Cl /EtOH/NH ‧
1
32.7, 129.1, 128.8, 127.8, 125.9, 117.4, 91.3, 79.1, 38.0, 18.2.
H
2
O ¼ 10:0.75:0.05). IR (KBr)
n
: 3410, 2973, 2866, 2359, 1658, 1597,
ꢁ
1
þ
1
C
490, 1366,1033 cm . HRMS (ESI) (M þ H) m/z 284.1393, calcd for
1
4
(
7
.3.8.3. 4-(Quinolin-6-yl)but-3-yn-1-amine (11b). Compound 11b
0.190 g, 1.45 mmol, 82.7%) was prepared starting from compound
b (0.570 g, 1.75 mmol) according to the general procedure, and
purified by silica gel column chromatography (CH Cl /EtOH/NH
16
H
18
N
3
O
2
284.1394. H NMR (DMSO‑d
6
, 400 MHz)
d: 9.21 (d,
0
J ¼ 4.6 Hz, 1 H, -CO-NH
2
), 8.87 (s, 1 H, 2 -quinolyl), 8.30 (d,
0
0
J ¼ 2.0 Hz, 1 H, 5 -quinolyl), 7.87 (d, J ¼ 8.9 Hz, 1 H, 7 -quinolyl), 7.81
0
2
2
3
‧
(dd, J
-CO-NH
NH eCH
3 H, -CH
1
¼ 8.9 Hz, J
2
¼ 2.1 Hz, 1 H, 8 -quinolyl), 7.52 (d, J ¼ 4.6 Hz, 1 H,
H
2
O ¼ 10:0.3:0.05). IR (KBr)
n
: 3447, 3025, 2949, 2363, 1654, 1569,
2
), 4.49 (q, J ¼ 7.1 Hz, 2 H, -CH
-), 2.56e2.52 (m, 2 H, NH eCH
, 100 MHz) d
2
CH
3
), 2.79 (t, J ¼ 6.7 Hz, 2 H,
CH
-), 1.38 (t, J ¼ 7.1 Hz,
: 175.2, 165.8, 148.7,
ꢁ1
þ
1
C
2
494, 1023, 842 cm . HRMS (ESI) (M þ H) m/z 197.1073, calcd for
2
2
2
2
2
1
13
13
H
13
N
2
197.1073. H NMR (CDCl
3
, 400 MHz)
d
: 8.91e8.82 (m, 1 H,
3
). C NMR (DMSO‑d
6
0
0
0
-quinolyl), 8.11e7.94 (m, 2 H, 5 -quinolyl, 4 -quinolyl), 7.90e7.84
138.5, 135.7, 129.4, 127.8, 120.2, 118.4, 112.3, 91.1, 80.6, 48.8, 41.6,
24.4, 14.9.
0
0
(
m, 1 H, 8 -quinolyl), 7.72e6.65 (m, 1 H, 7 -quinolyl), 7.41e7.35 (m,
0
1
H, 3 -quinolyl), 2.97 (t, J ¼ 6.4 Hz, 2 H, NH
2
eCH
2
-), 2.62 (t,
13
J ¼ 6.4 Hz, 2 H, NH
2
eCH
2
CH
2
-). C NMR (DMSO‑d , 175 MHz)
6
d
:
4.3.8.8. 6-(4-Aminobut-1-yn-1-yl)-1-methyl-4-oxo-1,4-
dihydroquinoline-3-carboxamide (11g). Compound 11g (0.0700 g,
0.260 mmol, 11.4%) was prepared starting from compound 7g
151.4, 146.8, 136.8, 132.7, 131.9, 129.2, 128.1, 122.7, 121.3, 87.9, 82.4,
3
8.2, 18.2.
(0.850g, 2.29 mmol) according to the general procedure, and pu-
4.3.8.4. 6-(4-Aminobut-1-yn-1-yl)quinolin-4(1H)-one
(11c).
rified by silica gel column chromatography (CH Cl /EtOH/NH ‧
2
2
3
Compound 11c (0.0960 g, 0.450 mmol, 28.1%) was prepared starting
from compound 7c (0.550 g, 1.60 mmol) according to the general
procedure, and purified by silica gel column chromatography
H
2
O ¼ 10:0.7:0.05). IR (KBr)
n
: 3426, 2973, 2360, 1659, 1597, 1496,
ꢁ1
þ
1033, 750 cm . HRMS (ESI) (M þ H) m/z 270.1232, calcd for
1
C
15
H
16
N
3
O
2
270.1237. H NMR (DMSO‑d
6
, 400 MHz)
d: 9.21 (d,
0
(
2
2
4
1
CH
2
Cl
2
/MeOH/NH
3
‧H
2
O ¼ 10:1:0.1). IR (KBr)
n
: 3680, 2973, 2866,
J ¼ 4.6 Hz, 1 H, -CO-NH
2
), 8.84 (s, 1 H, 2 -quinolyl), 8.30 (d,
ꢁ1
þ
0
0
363, 1587, 1483, 1332, 1033, 837 cm . HRMS (ESI) (M þ H) m/z
J ¼ 2.0 Hz, 1 H, 5 -quinolyl), 7.84 (dd, J
1
¼ 8.8 Hz, J
2
¼ 2.0 Hz, 1 H, 7 -
1
0
13.1021, calcd for C13
H
13
N
2
O 213.1022.
H
NMR (DMSO‑d
6
,
quinolyl), 7.78 (d, J ¼ 9.0 Hz,1 H, 8 -quinolyl), 7.50 (d, J ¼ 4.6 Hz, 1 H,
0
00 MHz)
H, 2 -quinolyl), 7.63 (dd, J
d: 8.07 (d, J ¼ 2.0 Hz, 1 H, 5 -quinolyl), 7.91 (d, J ¼ 7.5 Hz,
-CO-NH
NH eCH
(DMSO‑d
2
), 4.44 (br, 2 H, -CH
-), 2.65 (t, J ¼ 6.7 Hz, 2 H, NH
, 100 MHz) : 175.2, 165.9, 149.8, 139.7, 135.6, 129.1, 127.4,
2
-NH
2
), 3.99 (s, 3 H, -CH
3
), 2.89 (s, 2 H,
0
0
13
1
¼ 8.6 Hz, J
2
¼ 2.0 Hz, 1 H, 7 -quinolyl),
2
2
2
eCH CH -). C NMR
2
2
0
0
7
.51 (d, J ¼ 8.6 Hz, 1 H, 8 -quinolyl), 6.04 (d, J ¼ 7.4 Hz, 1 H, 3 -
6
d
quinolyl), 2.79 (t, J ¼ 6.8 Hz, 2 H, NH
2
eCH
, 100 MHz)
34.6, 128.4, 126.0, 119.3, 118.2, 109.5, 89.4, 81.4, 41.5, 24.0.
2
-), 2.55e2.51 (m, 2 H,
120.3, 118.6, 111.9, 90.8, 80.8, 41.6, 41.2, 23.8.
13
NH
2
eCH
2
CH
2
-). C NMR (DMSO‑d
6
d: 176.6, 140.1, 139.9,
1
4.3.8.9. 6-(4-Aminobut-1-yn-1-yl)-1-cyclopropyl-N-methyl-4-oxo-
1,4-dihydroquinoline-3-carboxamide (11h). Compound 11h (0.120 g,
4.3.8.5. 5-(4-Aminobut-1-yn-1-yl)nicotinamide
(11d).
0.390 mmol, 46.4%) was prepared starting from compound 7h
Compound 11d (0.110 g, 0.580 mmol, 26.2%) was prepared starting
from compound 7d (0.700 g, 2.21 mmol) according to the general
(0.370 g, 0.840 mmol) according to the general procedure, and
purified by silica gel column chromatography (CH Cl /EtOH/NH ‧
2 2 3

B.-Z. Fan et al. / European Journal of Medicinal Chemistry 193 (2020) 112222
19
H
2
O ¼ 10:0.3:0.05). IR (KBr)
n
: 3439, 2949, 2831, 2360, 1656, 1599,
EtOH, and 80% hydrazine hydrate (0.300 mL, 5.02 mmol) was
added. The mixture was stirred at reflux for 2 h. The resulting
mixture was cooled to room temperature. The insoluble solid was
filtered off. The filtrate was acidified with 2 M HCl and concentrate
to afford compound 16. The crude product was used directly in the
next step without further purification.
ꢁ
1
þ
1
C
486, 1364, 1033 cm . HRMS (ESI) (M þ H) m/z 310.1547, calcd for
1
18
H
20
N
3
O
2
310.1550. H NMR (DMSO‑d
6
, 400 MHz)
d: 9.63 (q,
0
J ¼ 4.8 Hz, 1 H, Ar-CO-NH-), 8.68 (s, 1 H, 2 -quinolyl), 8.27 (d,
0
0
J ¼ 2.0 Hz, 1 H, 5 -quinolyl), 8.12 (d, J ¼ 8.8 Hz, 1 H, 7 -quinolyl), 7.87
0
(
dd, J
1
¼8.9 Hz, J
2
¼ 2.1 Hz, 1 H, 8 -quinolyl), 3.85e3.61 (m, 3 H, 1 H-
cyclopropyl, -NH
J ¼ 6.8 Hz, 2 H, NH
.13e1.07 (m, 2 H, 2 H-cyclopropyl). C NMR (DMSO‑d
: 175.3, 164.7, 147.7, 140.3, 135.6, 129.0, 127.1, 120.4, 118.7, 111.7,
2
), 2.89e2.82 (m, 5 H, NH
2 2 3
eCH -, -CH ), 2.61 (t,
2
eCH CH -), 1.33e1.26 (m, 2 H, 2 H-cyclopropyl),
2
2
4.3.10. tert-Butyl but-3-yn-1-ylcarbamate (17)
13
1
d
6
, 100 MHz)
Di-tert-butyl dicarbonate (0.550 g, 2.51 mmol) was added to a
solution of compound 16 (0.260 g, 2.51 mmol) and trimethylamine
ꢀ
9
0.9, 80.7, 55.4, 41.3, 35.5, 26.0, 23.8, 8.0.
(1.05 mL, 7.53 mmol) in 8 mL of THF. The mixture was stirred at 0 C
for 10 min, and then at room temperature for 24 h. The THF was
removed by means of evaporation at reduced pressure. The residue
4
.3.8.10. Ethyl 6-(4-aminobut-1-yn-1-yl)-1-cyclopropyl-4-oxo-1,4-
dihydroquinoline-3-carboxylate (11i). Compound 11i (0.250 g,
.770 mmol, 52.0%) was prepared starting from compound 7i
0.670 g, 1.48 mmol) according to the general procedure, and pu-
2 2 3
was dissolved in CH Cl and washed with saturated NaHCO , water
0
(
and brine. The organic solvent was removed to afford compound 17.
The crude product was used directly for the next step without
further purification.
rified by silica gel column chromatography (CH
2
Cl
2
/EtOH/NH
3
‧
þ
H
2
O ¼ 10:0.3:0.05). HRMS (ESI) (M þ H) m/z 325.1549, calcd for
1
0
C
19
21
H N
2
O
3
325.1547. H NMR (CD
3
OD, 400 MHz)
d
: 8.54 (s, 1 H, 2 -
4.3.11. 6-(4-Aminobut-1-yn-1-yl)-1-cyclopropyl-4-oxo-1,4-
dihydroquinoline-3-carboxylic acid (11j)
0
quinolyl), 8.31 (d, J ¼ 2.0 Hz, 1 H, 5 -quinolyl), 8.18 (dd, J ¼ 8.9 Hz,
1
0
0
J
2
¼ 2.1 Hz, 1 H, 7 -quinolyl), 8.08 (d, J ¼ 8.9 Hz, 1 H, 8 -quinolyl),
.30 (q, J ¼ 7.1 Hz, 2 H, -CH CH ), 4.07e4.01 (m, 2 H, -NH ), 3.66 (tt,
¼ 7.3 Hz, J ¼ 4.0 Hz, 1 H, 1 H-cyclopropyl), 3.04e2.97 (m, 2 H,
NH eCH -), 2.15e2.06 (m, 2 H, NH eCH CH
-), 1.38 (t, J ¼ 7.1 Hz,
H, -CH ), 1.36e1.32 (m, 2 H, 2 H-cyclopropyl), 1.24e1.19 (m, 2 H,
To a mixture of 6 mL of acetonitrile and 6 mL of trimethylamine,
CuI (0.0380 g, 0.200 mmol) and 1-cyclopropyl-6-iodo-4-oxo-1,4-
dihydroquinoline-3-carboxylic acid (0.710 g, 2.00 mmol) were
added. The mixture was stirred for 20 min at room temperature.
Compound 17 (0.420 g, 2.51 mmol) and bis(triphenylphosphine)
palladium(II) dichloride (0.0700 g, 0.100 mmol) were added to the
4
2
3
2
J
1
2
2
2
2
2
2
3
2
3
H-cyclopropyl).
ꢀ
reaction vessel. The reaction mixture was stirred at 50 C for 24 h
4
.3.8.11. 3-(Quinolin-3-yl)prop-2-en-1-amine
(12a). Compound
under Ar. The reaction was quenched with water. The resulting
mixture was extracted with EtOAc. The organic layer was washed
with water and brine, and concentrated to afford intermediate Boc-
11j. The intermediate was purified by flash column chromatog-
12a was prepared starting from compound 8a according to the
general procedure, and used directly for the next step without
þ
further purification. HRMS (ESI) (M þ H) m/z 185.1062, calcd for
1
0
C
12
13
H N
2
185.1073. H NMR (DMSO‑d
6
, 700 MHz)
d
: 9.25 (s, 1 H, 2 -
raphy (CH
(0.630 g, 1.59 mmol, 63.4% in three step).
2
Cl
2
/MeOH/NH
3
‧H
2
O ¼ 10:2:0.5) to give pure Boc-11j
0
quinolyl), 8.82 (s, 1 H, 4 -quinolyl), 8.69e8.60 (m, 2 H, -NH
2
), 8.23
0
0
(
7
d, J ¼ 8.5 Hz, 1 H, 5 -quinolyl), 8.20 (d, J ¼ 8.3 Hz, 1 H, 8 -quinolyl),
Boc-11j (0.630 g, 1.59 mmol) was suspended in 32 mL of EtOAc
with stirring, and 15.8 mL of concentrated hydrochloric acid was
0
0
.93 (t, J ¼ 7.7 Hz, 1 H, 6 -quinolyl), 7.78 (t, J ¼ 7.6 Hz, 1 H, 7 -qui-
ꢀ
nolyl), 7.02 (d, J ¼ 16.1 Hz, 1 H, Ar-CH¼CH-), 6.74 (dt, J
1
¼ 16.2 Hz,
-).
added dropwise at 0 C. The mixture was stirred for 3 h, and then
J
2
¼ 6.4 Hz, 1 H, Ar-CH¼CH-), 3.69 (t, J ¼ 6.0 Hz, 2 H, -CH
2
treated with EtOAc. The precipitate was filtered and washed with
EtOAc to provide compound 11j (0.360 g, 1.21 mmol, 76.1%) as a
4
.3.8.12. 4-(Quinolin-3-yl)but-3-en-1-amine (13a). Compound 13a
yellow solid. IR (KBr)
n
: 3415, 2969, 2361, 1721, 1606, 1477, 1332,
ꢁ1
þ
was prepared starting from compound 9a according to the general
procedure, and used directly for the next step without further
purification.
1238, 952, 811 cm . HRMS (ESI) (M þ H) m/z 297.1233, calcd for
1
C
17
H
17
N
2
O
3
297.1234. H NMR (DMSO‑d
6
, 400 MHz)
d
: 14.87 (s, 1 H,
0
0
-COOH), 8.75 (s, 1 H, 2 -quinolyl), 8.42 (d, J ¼ 2.0 Hz, 1 H, 5 -qui-
0
nolyl), 8.28 (d, J ¼ 8.9 Hz, 1 H, 8 -quinolyl), 8.04 (dd, J
1
¼ 8.9 Hz,
0
4
.3.8.13. 3-(Quinolin-3-yl)propan-1-amine (14a). Compound 14a
was prepared starting from 2-(3-(quinolin-3-yl)propyl)isoindoline-
,3-dione according to the general procedure, and used directly for
J
2
¼ 2.0 Hz,1 H, 7 -quinolyl), 3.85 (tt, J
1
¼7.3 Hz, J
eCH
2
-), 1.36e1.28 (m, 2 H, 2 H-cyclopropyl), 1.23e1.16
2
¼ 4.0 Hz,1 H, 1 H-
cyclopropyl), 3.08 (q, J ¼ 6.3 Hz, 2 H, NH
2 H, NH eCH CH
(m, 2 H, 2 H-cyclopropyl). C NMR (DMSO‑d
2
2
-), 2.88 (t, J ¼ 6.9 Hz,
1
2
2
13
the next step without further purification. IR (KBr)
2
n
: 3426, 2966,
6
, 100 MHz) : 177.8,
d
ꢁ
1
1
þ
736, 2360, 1568, 1389, 1033, 771 cm . HRMS (ESI) (M þ H) m/z
166.0, 149.4, 141.0, 136.9, 129.0, 125.5, 121.1, 119.6, 108.2, 88.7, 81.4,
38.1, 36.4, 18.2, 8.1.
187.1220, calcd for C12
H
15
N
2
187.1230. H NMR (DMSO‑d
6
, 700 MHz)
0
0
d
: 9.32 (d, J ¼ 2.2 Hz, 1 H, 2 -quinolyl), 9.08 (d, J ¼ 2.0 Hz, 1 H, 4 -
0
quinolyl), 8.42 (d, J ¼ 8.6 Hz, 1 H, 5 -quinolyl), 8.40 (s, 2 H, -NH
2
),
4.3.12. 7-(4-(tert-Butoxycarbonyl)piperazin-1-yl)-1-cyclopropyl-6-
fluoro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid (19)
0
8
.27 (dd, J
¼ 8.5 Hz, J
¼ 8.1 Hz, J
1
¼ 8.3 Hz, J
¼ 6.9 Hz, J
¼ 6.8 Hz, J
2
¼ 1.2 Hz, 1 H, 8 -quinolyl), 8.07 (ddd,
0
J
J
1
2
3
¼ 1.5 Hz, 1 H, 6 -quinolyl), 7.90 (ddd,
Ciprofloxacin (0.500 g, 1.50 mmol) was suspended in 25 mL of
THF, and then trimethylamine (0.210 mL, 1.50 mmol) and di-tert-
butyl dicarbonate (0.340 g, 1.50 mmol) were added. The mixture
0
1
2
3
¼ 1.0 Hz, 1 H, 7 -quinolyl), 3.07 (t,
J ¼ 7.5 Hz, 2 H, -CH
2
-Ar), 2.87e2.80 (m, 2 H, -CH
2
-NH
2
), 2.09 (q,
: 146.4,
1
3
ꢀ
J ¼ 7.4 Hz, 2 H, -CH
2
CH
2
-Ar). C NMR (DMSO‑d
6
, 175 MHz)
d
was stirred at 0 C for 10 min, and then at room temperature for 8 h.
144.4, 137.5, 135.8, 133.8, 129.9, 129.0, 128.8, 121.5, 38.1, 29.0, 28.2.
The resulting mixture was concentrated and treated with petro-
leum ether. The precipitate was isolated by filtration and dried to
yield compound 19 (0.630 g, 1.46 mmol, 97.3%).
4
.3.8.14. 4-(Quinolin-3-yl)butan-1-amine (15a). Compound 15a
was prepared starting from 2-(4-(quinolin-3-yl)butyl)isoindoline-
,3-dione according to the general procedure, and used directly for
the next step without further purification.
1
4.3.13. 1-Cyclopropyl-6-fluoro-4-oxo-7-(piperazin-1-yl)-1,4-
dihydroquinoline-3-carboxamide (20)
Compound 19 (0.630 g, 1.46 mmol) was dissolved in 3 mL of
4
.3.9. But-3-yn-1-amine hydrochloride (16)
Compound 3 (0.500 g, 2.51 mmol) was suspended in 10 mL of
DMF. Then CDI (0.490 g, 3.00 mmol) was added. The mixture was
ꢀ
stirred at 65 C for 2 h, and then 20 mL of NH
3
‧H
2
O was added. The

20
B.-Z. Fan et al. / European Journal of Medicinal Chemistry 193 (2020) 112222
mixture was stirred at room temperature for another 2 h. The
20.8, 16.1, 11.0, 9.0, 8.3.
precipitate was filtered off to afford the intermediate Boc-20
0
(
0.610 g, 1.42 mmol, 97.3%) as a yellow solid.
4.3.16. 2 -O-Acetyl-3-O-descladinosyl-6-acryloylazithromycin (24)
Boc-20 (0.610 g, 1.42 mmol) was suspended in 30 mL of EtOAc,
To a mixture of compound 22 (5.00 g, 7.90 mmol) and trie-
thylamine (1.65 mL, 11.8 mmol) in toluene (30 mL), a solution of 3-
chloropropionyl chloride (1.00 ml, 10.3 mmol) in toluene (20 mL)
was slowly added dropwise at room temperature. After completion
of the reaction, the mixture was quenched with water. Toluene was
removed by rotary evaporation, 40 mL of water was added, and pH
and 15 mL of concentrated hydrochloric acid was added dropwise
ꢀ
at 0 C. The mixture was stirred for 3 h. The resulting mixture was
3 2
evaporated to remove the EtOAc and treated with NH ‧H O. The
insoluble solid was filtered off and washed with ether to obtain
compound 20 (0.430 g, 1.42 mmol, 97.2%) as a white solid. IR (KBr)
ꢁ1
n
: 3440, 2981, 2360, 1660, 1597, 1483, 1261, 1033 cm . HRMS (ESI)
3 2
was adjusted to 10 using NH ‧H O. The resulting mixture was
þ
1
(
(
1
2
3
M þ H) m/z 331.1560, calcd for C17
H
20FN
4
O
2
331.1565. H NMR
extracted twice with CH Cl . The organic layer was washed with
2
2
DMSO‑d
6
, 400 MHz)
d
: 9.22 (d, J ¼ 4.7 Hz, 1 H, -CO-NH
2
), 8.62 (s,
water and brine, and concentrated to yield compound 24. The crude
product was used in the next step without further purification.
0
0
H, 2 -quinolyl), 7.84 (d, J ¼ 13.6 Hz, 1 H, 5 -quinolyl), 7.51e7.44 (m,
0
þ
H, 8 -quinolyl, -CO-NH
.26e3.18 (m, 4 H, 4 H-piperazinyl), 2.96 (t, J ¼ 4.7 Hz, 4 H, 4 H-
¼ 7.5 Hz, J ¼ 5.5 Hz, 2 H, 2 H-cyclopropyl),
.13e1.06 (m, 2 H, 2 H-cyclopropyl). C NMR (DMSO‑d
: 174.7, 165.9, 153.8, 152.4, 147.4, 145.0, 139.0, 121.2, 111.8, 111.6,
10.9, 106.4, 50.6, 45.4, 35.4, 8.0.
2
), 3.77e3.69 (m, 1 H, 1 H-cyclopropyl),
HRMS (ESI) (M þ H) m/z 687.4410, calcd for C35
H
63
N
2
O
11 687.4426.
1
H NMR (CDCl
6-O-CO-CH¼CH
CH¼CH ), 5.77 (dd, J
4.79 (dd, J
3
, 500 MHz)
), 6.10 (dd, J
¼ 10.3 Hz, J
d
: 6.36 (dd, J
1
¼ 17.3 Hz, J
2
¼ 1.6 Hz, 1 H,
piperazinyl), 1.28 (dd, J
1
2
2
1
¼ 17.3 Hz, J
2
¼ 10.3 Hz, 1 H, 6-O-CO-
13
1
d
1
6
, 175 MHz)
2
1
2
¼ 1.6 Hz, 1 H, 6-O-CO-CH¼CH
2
),
0
0
1
¼10.4 Hz, J
2
¼ 7.6 Hz, 1 H, H-2 ), 4.68e4.60 (m, 3 H, H-1 ,
0
H-5, H-13), 3.55 (s, 1 H, H-11), 3.52e3.42 (m, 2 H, H-5 , H-3),
0
3
.36e3.24 (m, 1 H, 12-OH), 2.77e2.67 (m, 2 H, H-10, H-3 ), 2.63 (dq,
0
4
.3.14. 2 -O-Acetyl-3-O-descladinosylazithromycin (22)
J
1
¼10.0, J
2
¼ 6.8, 1 H, H-2), 2.56e2.46 (m, 2 H, H-9a, 11-OH), 2.38 (s,
1
M HCl (106 mL) was added dropwise to a stirred mixture of
3 H, -N-CH
3 H, 2 -O-CO-CH
3
), 2.26 (s, 6 H, -N(CH ), 2.14e2.08 (m, 1 H, H-4), 2.07 (s,
3 2
)
ꢀ
0
azithromycin (20.0 g, 26.7 mmol) in EtOH (35 mL) at 40 C for 1 h.
3
), 2.03e1.95 (m, 1 H, H-9b), 1.95e1.87 (m, 2 H, H-
0
The reaction mixture was quenched with NH
3
2
‧H O and extracted
14eq, H-7a), 1.76e1.67 (m, 2 H, H-4 a, H-8), 1.65 (s, 3 H, 6-CH
1.59e1.51 (m, 1 H, H-14ax), 1.39e1.29 (m, 2 H, H-7b, H-4 b),
1.27e1.22 (m, 6 H, 5 -CH
CH
3
),
0
twice with CH Cl at pH 10. The organic layer was washed with
2
2
0
water and brine, and dried to obtain 3-O-descladinosylazi-
thromycin as a white solid.
3
, 2-CH
3
), 1.10e1.05 (m, 6 H, 12-CH
), 0.91e0.85 (m, 6 H, 8-CH
: 177.5, 170.0, 166.3, 130.1,
3
, 10-
3
), 0.93 (d, J ¼ 7.3 Hz, 3 H, 4-CH
3
3
,
1
3
To a stirring solution of 3-O-descladinosylazithromycin (16.1 g,
15-CH
3
). C NMR (CDCl
3
, 100 MHz)
d
2
5
7.2 mmol) in CH
4.5 mmol). The reaction mixture was stirred at room temperature
. The
, water and
brine, and concentrated to yield compound 22 (16.4 g, 25.9 mmol,
2
Cl
2
(150 mL) was added Ac
2
O (5.15 mL,
129.9, 100.3, 87.6, 78.6, 78.2, 77.2, 75.9, 74.6, 71.6, 68.9, 63.4, 61.3,
44.5, 40.6, 40.2, 38.6, 37.2, 30.8, 21.5, 21.3, 21.1, 21.0, 20.7, 16.2, 11.0,
8.0.
for 1 h and quenched by the addition of saturated NaHCO
mixture was washed five times with saturated NaHCO
3
3
0
4.3.17. 2 -O-Acetyl-3-O-descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-
9
5.1%) as a white solid.
O-acryloylazithromycin (25)
2 2
To a solution of compound 24 (9.61 g, 14.0 mmol) in CH Cl
0
4
.3.15. 2 -O-Acetyl-3-O-descladinosyl-3-O-acryloyl-6-O-
(60 mL) under argon, 2-pyridylacetic acid hydrochloride (4.86 g,
28.0 mmol), DCC (5.77 g, 28.0 mmol), pyridine (4.00 mL,
acryloylazithromycin (23)
To a mixture of compound 22 (0.100 g, 0.160 mmol) and trie-
thylamine (0.220 mL,1.58 mmol) in acetonitrile (6 mL), a solution of
ꢀ
49.0 mmol) and DMAP (0.170 g, 1.40 mmol) were added at 0 C and
0
the mixture was stirred for 1 h. The N,N -dicyclohexylurea was
3
-chloropropionyl chloride (0.0430 mL, 0.440 mmol) in acetonitrile
filtered off, and the filtrate was successively washed with saturated
ꢀ
(
4 mL) was added dropwise at 80 C. The reaction mixture was
NH
trated by rotary evaporation. The residue was purified by silica gel
column chromatography (CH Cl /EtOH/NH ‧H
4 3
Cl, saturated NaHCO , water and saturated brine, and concen-
quenched with water. Acetonitrile was removed by rotary evapo-
ration. The resulting mixture was diluted with CH Cl , washed
twice with water and brine, and concentrated to yield compound
2
2
2
2
3
2
O ¼ 10:0.1:0.05) to
afford pure compound 25 (3.98 g, 4.94 mmol, 35.3%) as a yellow
þ
þ
2
3. HRMS (ESI) (M þ H) m/z 741.4542, calcd for C38
H
65
N
2
O
12
solid. HRMS (ESI) (M þ H) m/z 806.4792, calcd for C42
68 3 12
H N O
¼ 4.9 Hz,
1
1
7
-
41.4532. H NMR (CDCl
CH¼CH ), 6.46 (d, J ¼ 16.8 Hz, 1 H, -CH¼CH
¼ 10.4 Hz, 1 H, -CH¼CH ), 6.18 (dd, J ¼ 17.3 Hz, J
), 5.96 (dd, J ¼ 1.4 Hz, 1 H, -CH¼CH
¼ 10.4 Hz, J
¼ 1.7 Hz, 1 H, -CH¼CH ), 5.11 (d, J ¼ 10.6 Hz, 1 H,
¼ 10.5 Hz, J ¼ 7.5 Hz, 1 H, H-2 ), 4.67 (d,
3
, 700 MHz)
d
: 6.56 (d, J ¼ 17.3 Hz, 1 H,
), 6.24 (dd, J
¼17.3 Hz,
¼ 10.3 Hz, 1 H,
), 5.79
806.4798. H NMR (CDCl
3
, 700 MHz)
¼ 0.9 Hz, 1 H, H-pyridyl), 7.70 (td, J
d
: 8.55 (dd, J
¼ 1.8 Hz, 1 H, H-
¼ 7.5 Hz,
¼ 17.3 Hz,
¼ 10.3 Hz,
¼ 1.7 Hz, 1 H, 6-O-
1
2
2
1
J
2
1
¼ 7.7 Hz, J
2
J
2
2
1
2
pyridyl), 7.45 (d, J ¼ 7.8 Hz, 1 H, H-pyridyl), 7.23 (ddd, J
1
-
CH¼CH
¼10.3 Hz, J
H-3), 4.77 (dd, J
2
1
2
2
J
J
2
¼ 4.8 Hz, J
¼ 1.7 Hz, 1 H, 6-O-CO-CH¼CH
), 5.77 (dd, J
3
¼ 1.1 Hz, 1 H, H-pyridyl), 6.43 (dd, J
1
(
dd, J
1
2
1
2
2
2
), 6.16 (dd, J
1
¼17.3 Hz, J
2
0
2
1 H, 6-O-CO-CH¼CH
2
1
¼ 10.3 Hz, J
2
J ¼ 10.8 Hz, 1 H, H-13), 4.38 (s, 1 H, H-5), 4.20 (d, J ¼ 7.5 Hz, 1 H, H-
CO-CH¼CH
2
), 5.06 (d, J ¼ 10.5 Hz, 1 H, H-3), 4.80 (dd, J
1
¼ 10.5 Hz,
0
0
0
1
), 3.61 (s, 1 H, H-11), 3.35e3.28 (m, 1 H, H-5 ), 3.27e3.21 (m, 1 H,
J
2
¼ 7.4 Hz, 1 H, H-2 ), 4.64 (d, J ¼ 10.5 Hz, 1 H, H-13), 4.41 (s, 1 H, H-
0
12-OH), 2.88 (dd, J
1
¼ 10.8 Hz, J
2
¼ 6.7 Hz, 1 H, H-2), 2.73 (d,
5), 4.35 (d, J ¼ 7.4 Hz, 1 H, H-1 ), 3.99e3.94 (m, 2 H, 3-O-CO-CH
2
-),
0
0
J ¼ 7.2 Hz, 1 H, H-10), 2.66e2.53 (m, 2 H, H-3 , 11-OH), 2.50e2.43
3.58 (s, 1 H, H-11), 3.45e3.40 (m, 1 H, H-5 ), 3.24 (s, 1 H, 12-OH),
0
(
m, 1 H, H-9a), 2.38 (s, 3 H, -N-CH
3
), 2.36e2.32 (m, 1 H, H-4), 2.28 (s,
2.89e2.79 (m, 2 H, H-3 , H-2), 2.74e2.69 (m, 1 H, H-10), 2.55 (s, 1 H,
0
6
9
H, -N(CH
3
)
2
), 2.10 (s, 1 H, 2 -O-CO-CH
b), 1.97e1.91 (m, 1 H, H-14eq), 1.87e1.77 (m, 2 H, H-7a, H-8),
3
), 2.04 (t, J ¼ 11.5 Hz, 1 H, H-
11-OH), 2.49e2.43 (m, 1 H, H-9a), 2.37 (s, 3 H, -N-CH
3
), 2.30 (s, 6 H,
0
-N(CH
3
)
2
), 2.29e2.26 (m, 1 H, H-4), 2.10 (s, 3 H, 2 -O-CO-CH
3
),
0
1.72e1.68 (m, 1 H, H-4 a), 1.62 (s, 3 H, 6-CH
3
), 1.59e1.53 (m, 1 H, H-
2.06e1.98 (m, 1 H, H-9b), 1.97e1.89 (m, 1 H, H-14eq), 1.87e1.82 (m,
0
0
14ax), 1.35e1.27 (m, 1 H, H-4 b), 1.24e1.20 (m, 1 H, H-7b), 1.19 (d,
1 H, H-7a), 1.81e1.76 (m, 1 H, H-8), 1.74e1.68 (m, 1 H, H-4 a), 1.64 (s,
0
0
J ¼ 6.1 Hz, 3 H, 5 -CH
3
), 1.11 (d, J ¼ 6.8 Hz, 3 H, 2-CH
), 1.04 (d, J ¼ 7.4 Hz, 3 H, 4-CH ), 0.93e0.85 (m,
: 176.2,169.9,165.6,
3
), 1.10e1.07 (m,
3 H, 6-CH
3
), 1.58e1.52 (m, 1 H, H-14ax), 1.36e1.32 (m, 1 H, H-4 b),
0
6
6
H, 12-CH
3
, 10-CH
,15-CH
3
3
1.28e1.24 (m, 1 H, H-7b), 1.21 (d, J ¼ 6.1 Hz, 3 H, 5 -CH
3
), 1.10e1.06
), 0.99 (d,
), 0.86 (t, J ¼ 7.3 Hz,
: 176.1, 169.9, 169.7, 165.7,
13
H, 8-CH
3
3
). C NMR (CDCl
3
,175 MHz)
d
(m, 6 H, 10-CH
3
, 12-CH
), 0.91 (d, J ¼ 6.9 Hz, 3 H, 8-CH
). C NMR (CDCl , 175 MHz)
3
), 1.04 (d, J ¼ 6.8 Hz, 3 H, 2-CH
3
165.0, 131.9, 130.0, 129.9, 128.5, 100.0, 86.9, 78.9, 78.5, 77.7, 74.6,
J ¼ 7.4, 3 H, 4-CH
3
3
1
3
71.4, 68.9, 63.5, 61.6, 43.4, 40.7, 36.7, 30.6, 29.7, 26.9, 21.5, 21.2, 21.0,
15-CH
3
3
d

B.-Z. Fan et al. / European Journal of Medicinal Chemistry 193 (2020) 112222
21
1
7
3
53.9, 149.3, 136.6, 130.0, 129.9, 124.1, 122.3, 100.4, 86.9, 78.9, 78.4,
8.1, 77.6, 74.6, 71.5, 69.0, 63.2, 61.5, 49.2, 44.0, 43.5, 40.7, 36.7, 34.0,
0.7, 27.0, 25.6, 25.0, 21.6, 21.3, 21.0, 16.1, 11.0, 9.0, 8.4.
pyridyl), 8.19 (d, J ¼ 2.0 Hz, 1 H, H-quinolyl), 8.06 (d, J ¼ 8.4 Hz, 1 H,
H-quinolyl), 7.75 (dd, J ¼ 1.4 Hz, 1 H, H-quinolyl),
¼ 8.2 Hz, J
7.70e7.64 (m, 2 H, H-quinolyl, H-pyridyl), 7.53 (ddd, J
¼ 8.1 Hz,
¼ 6.9 Hz, J ¼ 1.2 Hz, 1 H, H-quinolyl), 7.41 (dt, J ¼7.9 Hz, J ¼ 1.1,
1 H, H-pyridyl), 7.19 (ddd, J ¼ 4.9 Hz, J ¼ 1.1 Hz, 1 H, H-
¼7.5 Hz, J
pyridyl), 5.11 (dd, J
1
2
1
J
2
3
1
2
4.3.18. General procedure for the synthesis of compounds 26a-26u,
1
2
3
and 26w
Compound 25 was dissolved in MeOH and stirred at reflux for
h. MeOH was removed by rotary evaporation to yield the crude
product of 3-O-descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-
1
¼ 10.6 Hz, J ¼ 2.0, 1 H, H-3), 4.76 (dd,
2
J
1
¼10.8 Hz, J
2
¼ 2.0, 1 H, H-13), 4.32 (d, J ¼ 3.1 Hz, 1 H, H-5), 4.24 (d,
0
2
J ¼ 7.2 Hz, 1 H, H-1 ), 3.94 (dd, J
1
¼17.6 Hz, J
2
¼ 16.0 Hz, 2 H, 3-O-CO-
0
CH
2
-), 3.59 (s, 1 H, H-11), 3.47e3.39 (m, 2 H, H-5 , 12-OH), 3.23 (dd,
0
acryloylazithromycin.
J
1
¼ 10.2 Hz, J
2
¼ 7.2 Hz, 1 H, H-2 ), 3.12e2.80 (m, 5 H, 6-O-CO-
To a solution of 3-O-descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-
O-acryloylazithromycin (1 eq) in anhydrous MeOH under argon,
amines and N,N-diisopropylethylamine (5 eq) were added. The
reaction mixture was stirred at 65 C for 8 h, and then cooled to
room temperature, diluted with CH
CH
CH
2
CH
2
eNHeCH
eNHeCH
2
CH
2
C≡CeAr, H-2), 2.72e2.54 (m, 7 H, 6-O-CO-
C≡CeAr, H-10, H-3 11-OH), 2.46e2.39 (m,
0
2
CH
2
2
CH
2
3 3 2
1 H, H-9a), 2.37 (s, 3 H, -N-CH ), 2.30 (s, 6 H, -N(CH ) ), 2.28e2.25
ꢀ
(m, 1 H, H-4), 2.04e1.96 (m, 1 H, H-9b), 1.94e1.79 (m, 3 H, H-14eq,
0
2
Cl
2
, washed with water and
H-7a, H-8), 1.66e1.59 (m, 4 H, H-4 a, 6-CH
3
), 1.56e1.46 (m, 1 H, H-
brine, and concentrated by rotary evaporation. The residue was
purified by silica gel column chromatography to afford pure prod-
ucts 26a-26u, 26w.
14ax), 1.34 (dd, J
4 b), 1.18e1.13 (m, 6 H, 5 -CH
1.06e1.01 (m, 6 H, 10-CH
1
¼14.0 Hz, J
2
¼ 6.1, 1 H, H-7b), 1.25e1.19 (m, 1 H, H-
0
0
3
, 4-CH
3
), 1.07 (s, 3 H, 12-CH
3
),
),
3
, 2-CH
3
), 0.87 (d, J ¼ 6.8 Hz, 3 H, 8-CH
3
1
3
0.78 (t, J ¼ 7.3 Hz, 3 H, 15-CH
3 3
). C NMR (CDCl , 100 MHz) d: 176.0,
4
.3.18.1. 3-O-Descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-(3-{[3-
172.0, 170.0, 154.0, 152.6, 149.2, 146.6, 138.1, 136.6, 129.7, 129.3,
127.5, 127.3, 127.1, 124.2, 122.3, 118.0, 103.2, 91.8, 87.3, 79.5, 79.0,
78.2, 77.9, 77.3, 74.6, 70.8, 69.5, 65.5, 61.7, 48.1, 44.3, 44.0, 43.5, 40.4,
38.6, 36.8, 35.4, 28.7, 27.5, 21.2, 20.5, 16.3, 16.1, 10.8, 9.3, 8.2.
(
quinolin-3-yl)prop-2-yn-1-yl]amino}propanoyl)azithromycin (26a).
Compound 26a (70.1 mg, 0.0740 mmol, 11.2%) was prepared start-
ing from 3-O-descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-acryl-
oylazithromycin (0.510 g, 0.660 mmol) and compound 10a (0.220 g,
1
.19 mmol) according to the general procedure (column chroma-
4.3.18.3. 3-O-Descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-(3-{[3-
(quinolin-3-yl)prop-2-en-1-yl]amino}propanoyl)azithromycin (26c).
Compound 26c (39.8 mg, 0.0420 mmol, 6.46%) was prepared
starting from 3-O-descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-
acryloylazithromycin (0.500 g, 0.650 mmol) and compound 12a
(0.350 g, 1.91 mmol) according to the general procedure (column
tography eluents: CH
2
Cl
2
/EtOH/NH
3
‧H
2
O ¼ 10:0.2:0.05). HRMS
þ
1
(
ESI) (M þ H) m/z 946.5522, calcd for C52
H
76
N
5
O
11 946.5536. H
: 8.89 (d, J ¼ 2.1 Hz, 1 H, H-quinolyl), 8.49
¼ 1.9 Hz, J ¼ 0.9 Hz, 1 H, H-pyridyl), 8.21 (d,
NMR (CDCl
3
, 400 MHz) d
(
ddd, J
1
¼ 5.0 Hz, J
2
3
J ¼ 1.7 Hz, 1 H, H-quinolyl), 8.07 (d, J ¼ 8.4 Hz, 1 H, H-quinolyl), 7.75
(
dd, J
1
¼ 8.1 Hz, J
¼ 6.9 Hz, J ¼ 1.5 Hz, 1 H, H-quinolyl), 7.63 (td, J
¼ 1.8 Hz, 1 H, H-pyridyl), 7.54 (ddd, J ¼ 8.2 Hz, J
2
¼ 1.4 Hz, 1 H, H-quinolyl), 7.70 (ddd, J
1
¼ 8.4 Hz,
¼ 7.7 Hz,
chromatography eluents: CH
2
Cl
2
/EtOH/NH
3
‧H
2
O ¼ 10:0.25:0.05).
þ
J
J
J
2
2
3
3
1
HRMS (ESI) (M þ H) m/z 948.5684, calcd for C52
78 5 11
H N O
1
1
2
¼ 6.9 Hz,
948.5692. H NMR (CDCl
quinolyl), 8.48 (dt, J
¼ 4.8 Hz, J
J ¼ 8.4 Hz, 1 H, H-quinolyl), 8.02 (d, J ¼ 2.1 Hz, 1 H, H-quinolyl), 7.76
(d, J ¼ 8.4 Hz, 1 H, H-quinolyl), 7.65 (ddd, J ¼ 8.4 Hz, J ¼ 6.9 Hz,
¼ 1.5 Hz, 1 H, H-quinolyl), 7.59 (td, J ¼ 7.7 Hz, J ¼ 1.9 Hz, 1 H, H-
pyridyl), 7.51 (ddd, J ¼ 6.8 Hz, J ¼ 1.2 Hz, 1 H, H-qui-
¼ 8.1 Hz, J
nolyl), 7.36 (d, J ¼ 8.0 Hz, 1 H, H-pyridyl), 7.15 (ddd, J ¼ 7.6 Hz,
¼ 4.9 Hz, J ¼ 1.1 Hz, 1 H, H-pyridyl), 6.74 (d, J ¼ 16.0, 1 H,
3
, 400 MHz)
d
: 8.97 (d, J ¼ 2.2 Hz, 1 H, H-
¼ 1.2 Hz, 1 H, H-quinolyl), 7.39 (d, J ¼ 7.8 Hz, 1 H, H-pyridyl), 7.17
1
2
¼ 1.5 Hz, 1 H, H-pyridyl), 8.06 (d,
(
ddd, J
1
¼ 7.6 Hz, J
2
¼ 4.9 Hz, J ¼ 1.2 Hz, 1 H, H-pyridyl), 5.12 (d,
3
J ¼ 11.0 Hz, 1 H, H-3), 4.75 (dd, J
1
¼ 10.8 Hz, J
2
¼ 2.0 Hz, 1 H, H-13),
1
2
0
4
.34 (d, J ¼ 3.1 Hz, 1 H, H-5), 4.25 (d, J ¼ 7.2 Hz, 1 H, H-1 ), 3.93 (dd,
J
3
1
2
J
1
¼ 18.4 Hz, J
CH
.24 (dd, J
2
¼ 15.8 Hz, 2 H, 3-O-CO-CH
2
-), 3.74 (s, 2 H, -NH-
C≡CeAr), 3.60 (s, 1 H, H-11), 3.49e3.40 (m, 2 H, H-5 , 12-OH),
1
2
3
0
2
1
0
3
1
¼10.2 Hz, J
2
¼ 7.2 Hz, 1 H, H-2 ), 3.18e2.97 (m, 2 H, 6-O-
J
2
3
CO-CH
CO-CH
2
CH
CH
2
eNH-), 2.88e2.80 (m, 1 H, H-2), 2.72e2.56 (m, 5 H, 6-O-
-CH¼CH-Ar), 6.55 (dt, J
1
¼ 16.0 Hz, J ¼ 6.2 Hz, 1 H, -CH¼CH-Ar),
2
0
2
2
eNH-, H-3 , H-10, 11-OH), 2.45e2.40 (m, 1 H, H-9a),
5.11 (d, J ¼ 10.0 Hz, 1 H, H-3), 4.79 (d, J ¼ 9.6 Hz, 1 H, H-13), 4.39 (d,
0
2
4
.38 (s, 3 H, -N-CH
), 2.04e1.97 (m, 1 H, H-9b), 1.94e1.86 (m, 2 H, H-14eq, H-7a),
3
), 2.32 (s, 6 H, -N(CH
3
)
2
), 2.29e2.25 (m, 1 H, H-
J ¼ 3.0 Hz, 1 H, H-5), 4.25 (d, J ¼ 7.3 Hz, 1 H, H-1 ), 3.93 (dd,
J
1
¼18.8 Hz, J
2
¼ 16.0 Hz, 2 H, 3-O-CO-CH
2
-), 3.62 (s, 1 H, H-11), 3.57
0
0
1.85e1.78 (m, 1 H, H-8), 1.70e1.64 (m, 1 H, H-4 a), 1.62 (s, 3 H, 6-
(d, J ¼ 6.0 Hz, 2 H, -NH-CH
2
CH¼CH-), 3.49e3.40 (m, 2 H, H-5 , 12-
0
CH
.26e1.22 (m, 1 H, H-4 b), 1.19 (d, J ¼ 6.1 Hz, 3 H, 5 -CH
J ¼ 7.4 Hz, 3 H, 4-CH ), 1.10e1.01 (m, 9 H, 12-CH , 10-CH
.87 (d, J ¼ 6.8 Hz, 3 H, 8-CH ), 0.82 (t, J ¼ 7.3 Hz, 6 H, 15-CH
NMR (CDCl , 100 MHz)
46.7, 138.4, 136.6,129.8,129.3,127.6, 127.3, 127.1, 124.2, 122.3,117.5,
03.2, 91.2, 87.3, 80.7, 78.9, 78.2, 77.8, 77.2, 74.6, 70.8, 69.4, 65.5,
1.7, 44.0, 43.5, 40.4, 39.0, 38.6, 36.9, 35.1, 28.9, 27.4, 21.2, 21.2, 21.0,
6.2, 16.1, 10.9, 9.3, 8.3.
3
), 1.58e1.49 (m, 1 H, H-14ax), 1.38e1.31 (m, 1 H, H-7b),
OH), 3.24 (dd, J
1
¼10.2 Hz, J
2
¼ 7.2 Hz, 1 H, H-2 ), 3.12e2.93 (m, 2 H,
0
0
1
3
), 1.16 (d,
6-O-CO-CH
6-O-CO-CH
2
CH
CH
2
eNH-), 2.88e2.79 (m, 1 H, H-2), 2.76e2.57 (m, 5 H,
0
3
3
3
, 2-CH
3
),
C
2
2
eNH-, H-10, H-3 ,11-OH), 2.47e2.40 (m, 1 H, H-9a),
1
3
0
3
3
).
3 3 2
2.38 (s, 3 H, -N-CH ), 2.30 (s, 6 H, -N(CH ) ), 2.28e2.23 (m, 1 H, H-
3
d: 176.1, 172.1, 170.0, 154.0, 152.4, 149.2,
4), 2.05e1.97 (m, 1 H, H-9b), 1.95e1.85 (m, 2 H, H-14eq, H-7a),
0
1
1
6
1
1.84e1.75 (m, 1 H, H-8), 1.68e1.63 (m, 1 H, H-4 a), 1.61 (s, 3 H, 6-
CH
1.25e1.20 (m, 1 H, H-4 b), 1.20e1.14 (m, 6 H, 5 -CH
1.10e1.04 (m, 6 H, 12-CH , 10-CH
), 1.01 (d, J ¼ 6.8 Hz, 3 H, 2-CH
.88 (d, J ¼ 6.8 Hz, 3 H, 8-CH ), 0.80 (t, J ¼ 7.3 Hz, 3 H, 15-CH
NMR (CDCl , 100 MHz)
3
), 1.57e1.48 (m, 1 H, H-14ax), 1.39e1.32 (m, 1 H, H-7b),
0
0
3
, 4-CH
3
),
),
C
3
3
3
1
3
0
3
3
).
4
.3.18.2. 3-O-Descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-(3-{[4-
3
d: 176.1, 172.0, 170.0, 154.0, 149.5, 149.2,
(
quinolin-3-yl)but-3-yn-1-yl]amino}propanoyl)azithromycin (26b).
147.4, 136.6, 132.2, 130.0, 129.2, 129.0, 128.8, 128.0, 127.8, 126.8,
124.1, 122.2, 103.2, 87.4, 79.5, 79.1, 78.3, 77.8, 77.3, 74.6, 70.8, 69.4,
65.5, 61.7, 51.3, 44.0, 44.0, 43.4, 40.4, 36.8, 34.8, 28.8, 27.3, 21.2, 21.2,
21.0, 16.4, 16.1, 10.9, 9.3, 8.1.
Compound 26b (62.1 mg, 0.0650 mmol, 16.7%) was prepared
starting from 3-O-descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-
acryloylazithromycin (0.300 g, 0.390 mmol) and compound 11a
(
0.310 g, 1.56 mmol) according to the general procedure (column
chromatography eluents: CH
2
Cl
2
/EtOH/NH
3
‧H
2
O ¼ 10:0.2:0.05).
4.3.18.4. 3-O-Descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-(3-{[4-
(quinolin-3-yl)but-3-en-1-yl]amino}propanoyl)azithromycin (26d).
Compound 26d (27.1 mg, 0.0280 mmol, 7.37%) was prepared
starting from 3-O-descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-
þ
HRMS (ESI) (M þ H) m/z 960.5690, calcd for C53
78 5 11
H N O
1
9
60.5692. H NMR (CDCl
3
, 400 MHz)
d
: 8.89 (d, J ¼ 2.1 Hz, 1 H, H-
quinolyl), 8.51 (ddd, J
1
¼ 4.9 Hz, J
2
¼ 1.9 Hz, J
3
¼ 0.9 Hz, 1 H, H-

22
B.-Z. Fan et al. / European Journal of Medicinal Chemistry 193 (2020) 112222
acryloylazithromycin (0.290 g, 0.380 mmol) and compound 13a
0.360 g, 1.81 mmol) according to the general procedure (column
4.3.18.6. 3-O-Descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-(3-{[4-
(quinolin-3-yl)butyl]amino}propanoyl)azithromycin (26f).
(
chromatography eluents: CH
2
Cl
2
/EtOH/NH
3
‧H
2
O ¼ 10:0.5:0.03).
Compound 26f (32.0 mg, 0.0330 mmol, 7.86%) was prepared
starting from 3-O-descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-
acryloylazithromycin (0.320 g, 0.420 mmol) and compound 15a
(0.260 g, 0.800 mmol) according to the general procedure (column
þ
HRMS (ESI) (M þ H) m/z 962.5852, calcd for C53
80 5 11
H N O
1
9
8
1
2
3
62.5849. H NMR (CDCl , 400 MHz) d: 8.97 (s, 1 H, H-quinolyl),
.51 (s, 1 H, H-pyridyl), 8.05 (d, J ¼ 8.5 Hz, 1 H, H-quinolyl), 8.00 (s,
H, H-quinolyl), 7.77 (d, J ¼ 8.2 Hz, 1 H, H-quinolyl), 7.69e7.59 (m,
H, H-quinolyl, H-pyridyl), 7.54e7.47 (m, 1 H, H-quinolyl), 7.40 (d,
chromatography eluents: CH
HRMS (ESI) (M þ H) m/z 964.6009, calcd for C53
2
Cl
2
/EtOH/NH
3
‧H
2
O ¼ 10:0.5:0.05).
þ
82 5 11
H N O
1
J ¼ 7.2 Hz, 1 H, H-pyridyl), 7.21e7.15 (m, 1 H, H-pyridyl), 6.60 (d,
964.6005. H NMR (CDCl
quinolyl), 8.50 (ddd, J
¼ 5.0 Hz, J
pyridyl), 8.06 (d, J ¼ 8.4 Hz, 1 H, H-quinolyl), 7.91 (d, J ¼ 2.2 Hz, 1 H,
H-quinolyl), 7.76 (dd, J ¼ 1.4 Hz, 1 H, H-quinolyl),
¼ 8.3 Hz, J
7.67e7.61 (m, 2 H, H-quinolyl, H-pyridyl), 7.50 (ddd, J
¼ 8.1 Hz,
¼ 6.8 Hz, J ¼ 1.2 Hz, 1 H, H-quinolyl), 7.38 (d, J ¼ 8.0 Hz, 1 H, H-
pyridyl), 7.18 (ddd, J
3
, 400 MHz)
d
: 8.76 (d, J ¼ 2.3 Hz, 1 H, H-
J ¼ 15.9, 1 H, -CH¼CH-Ar), 6.50e6.40 (m, 1 H, -CH¼CH-Ar), 5.10 (d,
1
2
¼ 1.9 Hz, J
3
¼ 0.9 Hz, 1 H, H-
J ¼ 10.5 Hz, 1 H, H-3), 4.78 (d, J ¼ 10.5 Hz, 1 H, H-13), 4.36 (s, 1 H, H-
0
5
3
1
), 4.24 (d, J ¼ 6.0 Hz, 1 H, H-1 ), 4.00e3.89 (m, 2 H, 3-O-CO-CH
2
-),
1
2
0
.60 (s, 1 H, H-11), 3.55e3.31 (m, 2 H, H-5 , 12-OH), 3.27e3.19 (m,
1
0
H,
H-2 ),
3.14e2.79
(m,
5
H,
6-O-CO-
J
2
3
CH
CH
2
CH
CH
2
eNHeCH
eNHeCH
2
CH
2
CH¼CH-Ar, H-2), 2.74e2.50 (m, 7 H, 6-O-CO-
1
¼ 7.6 Hz, J
2
¼ 4.9 Hz, J ¼ 1.2 Hz, 1 H, H-pyr-
3
0
2
2
2
CH
2
CH¼CH-Ar, H-10, H-3 , 11-OH), 2.45e2.38
idyl), 5.09 (d, J ¼ 9.6 Hz, 1 H, H-3), 4.83 (d, J ¼ 10.0 Hz, 1 H, H-13),
0
(
m, 1 H, H-9a), 2.36 (s, 3 H, -N-CH
3
), 2.30 (s, 6 H, -N(CH
3
)
2
),
4.40 (d, J ¼ 2.9 Hz, 1 H, H-5), 4.23 (d, J ¼ 7.3 Hz, 1 H, H-1 ), 3.93 (dd,
2
.28e2.22 (m,1 H, H-4), 2.05e1.95 (m,1 H, H-9b),1.94e1.83 (m, 2 H,
J
1
¼ 18.4 Hz, J
2
¼ 16.0 Hz, 2 H, 3-O-CO-CH
2
-), 3.60 (s, 1 H, H-11),
0
0
H-7a, H-14eq), 1.94e1.73 (m, 1 H, H-8), 1.67e1.62 (m, 1 H, H-4 a),
.60 (s, 3 H, 6-CH ),1.57e1.44 (m,1 H, H-14ax),1.39e1.30 (m,1 H, H-
b), 1.30e1.23 (m, 1 H, H-4 b), 1.22e1.12 (m, 6 H, 5 -CH
.11e0.98 (m, 9 H, 12-CH , 10-CH , 2-CH ), 0.92e0.83 (m, 3 H, 8-
CH ), 0.83e0.75 (m, 3 H, 15-CH ). C NMR (CDCl , 100 MHz)
76.0,172.0,170.1,154.0,152.0,149.4,149.2,147.2,136.6,134.5,131.9,
30.5, 130.4, 129.2, 128.9, 128.7, 128.6, 128.1, 127.9, 103.2, 87.5, 79.5,
3.47e3.37 (m, 2 H, H-5 , 12-OH), 3.23 (dd, J
1
¼ 10.2 Hz, J ¼ 7.2 Hz,
2
0
1
7
3
1 H, H-2 ), 3.12e2.88 (m, 2 H, 6-O-CO-CH
2
CH
2
eNH-), 2.88e2.74 (m,
0
0
0
3
, 4-CH
3
),
5 H, H-2, -NH-CH
OH, 6-O-CO-CH CH
3 2
CH ), 2.29 (s, 6 H, -N(CH )
2
(CH
2
)
2
CH
2
-Ar), 2.72e2.53 (m, 5 H, H-10, H-3 , 11-
1
3
3
3
2
2
-Ar), 2.46e2.38 (m, 1 H, H-9a), 2.36 (s, 3 H, -N-
), 2.27e2.19 (m, 1 H, H-4), 2.04e1.94 (m,
13
3
3
3
d:
3
1
1
1 H, H-9b), 1.94e1.83 (m, 2 H, H-14eq, H-7a), 1.82e1.64 (m, 5 H, H-8,
0
-NH-CH
2
CH
2
CH
2
CH
2
-Ar), 1.62 (s, 1 H, H-4 a), 1.58 (s, 3 H, 6-CH
3
),
7
4
9.2, 78.2, 77.8, 77.2, 74.6, 70.8, 69.5, 65.5, 61.7, 48.8, 44.4, 44.0, 43.5,
0.4, 40.4, 38.6, 37.7, 36.8, 34.7, 33.0, 28.8, 27.4, 21.2, 21.0, 16.5, 16.1,
1.56e1.45 (m, 1H, H-14ax), 1.39e1.32 (m, 1 H, H-7b), 1.28e1.20 (m,
0
0
1 H, H-4 b), 1.20e1.12 (m, 6 H, 5 -CH
3
, 4-CH
3
), 1.07 (s, 3 H, 12-CH
3
),
10.8, 9.3, 8.0.
1.04 (d, J ¼ 6.8 Hz, 3 H, 10-CH
3
), 1.00 (d, J ¼ 6.8 Hz, 3 H, 2-CH
3
), 0.87
3
). C NMR
1
3
(
d, J ¼ 6.8 Hz, 3 H, 8-CH
3
), 0.78 (t, J ¼ 7.3 Hz, 3 H, 15-CH
(
CDCl , 100 MHz) : 176.0, 171.9, 170.1, 154.0, 152.0, 149.2, 146.8,
3
d
4
.3.18.5. 3-O-Descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-(3-{[3-
136.6, 134.7, 134.2, 128.6, 128.2, 127.4, 126.5, 124.2,122.3, 103.3, 87.7,
79.6, 79.3, 78.3, 77.8, 77.2, 74.5, 70.7, 69.5, 65.5, 61.7, 49.0, 44.3, 44.0,
43.4, 40.4, 38.6, 36.6, 34.2, 32.9, 32.7, 28.7, 28.5, 28.3, 27.3, 21.3, 21.2,
21.0, 16.6, 16.1, 10.8, 9.3, 7.9.
(
quinolin-3-yl)propyl]amino}propanoyl)azithromycin (26e).
Compound 26e (40.6 mg, 0.0430 mmol, 6.62%) was prepared
starting from 3-O-descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-
acryloylazithromycin (0.500 g, 0.650 mmol) and compound 14a
(
0.140 g, 0.770 mmol) according to the general procedure (column
4.3.18.7. 3-O-Descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-[3-({2-
[(3-carboxy-7-chloro-1-cyclopropyl-1,4-dihydro-4-oxoquinolin-6-yl)
amino]ethyl}amino)propanoyl]azithromycin (26g). Compound 26g
(40.0 mg, 0.0370 mmol, 21.8%) was prepared starting from 3-O-
descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-acryloylazithromycin
(0.130 g, 0.170 mmol) and 6-(2-amino-ethylamino)-7-chloro-1-
chromatography eluents: CH
2
Cl
2
/EtOH/NH
3
‧H
2
O ¼ 10:0.25:0.05).
þ
HRMS (ESI) (M þ H) m/z 950.5848, calcd for C52
80 5 11
H N O
1
9
50.5849. H NMR (CDCl
quinolyl), 8.47 (ddd, J
¼ 4.9 Hz, J
pyridyl), 8.07 (d, J ¼ 8.4 Hz, 1 H, H-quinolyl), 7.94 (d, J ¼ 2.2 Hz, 1 H,
H-quinolyl), 7.75 (dd, J ¼ 1.4 Hz, 1 H, H-quinolyl), 7.65
¼ 8.2 Hz, J
ddd, J ¼ 1.5 Hz, 1 H, H-quinolyl), 7.59 (td,
¼ 6.8 Hz, J
¼ 1.8 Hz, 1 H, H-pyridyl), 7.51 (ddd, J ¼ 8.1 Hz,
¼ 1.2 Hz, 1 H, H-quinolyl), 7.36 (d, J ¼ 8.0 Hz, 1 H, H-
¼7.5 Hz, J ¼ 4.9 Hz, J ¼ 1.1 Hz,1 H, H-pyridyl),
.09 (d, J ¼ 10.4 Hz, 1 H, H-3), 4.80 (d, J ¼ 9.6 Hz, 1 H, H-13), 4.41 (d,
3
, 400 MHz)
d
: 8.77 (d, J ¼ 2.2 Hz, 1 H, H-
1
2
¼ 1.9 Hz, J
3
¼ 0.9 Hz, 1 H, H-
1
2
cyclopropyl-4-oxo-1,4-dihydro-quinoline-3-carboxylic
acid
(
1
¼ 8.4 Hz, J
¼ 7.7 Hz, J
¼ 6.8 Hz, J
2
3
(0.110 g, 0.320 mmol) according to the general procedure (column
J
J
1
2
1
chromatography eluents: CH
2
Cl
2
/MeOH/NH
3
‧H
2
O ¼ 10:0.8:0.5).
82ClN
: 8.69 (s, 1 H, H-quinolyl),
þ
2
3
HRMS (ESI) (M þ H) m/z 1085.5578, calcd for C55
H
6 14
O
1
pyridyl), 7.14 (ddd, J
1
2
3
1085.5572. H NMR (CDCl
3
, 400 MHz)
d
5
8.49 (s, 1 H, H-pyridyl), 8.00 (s, 1 H, H-quinolyl), 7.66 (t, J ¼ 7.8 Hz,
1 H, H-pyridyl), 7.48 (s, 1 H, H-quinolyl), 7.39 (d, J ¼ 8 Hz, 1 H, H-
pyridyl), 7.22e7.15 (m, 1 H, H-pyridyl), 5.42 (s, 1 H, -NH-Ar), 5.07 (d,
0
J ¼ 2.9 Hz, 1 H, H-5), 4.24 (d, J ¼ 7.2 Hz, 1 H, H-1 ), 3.92 (dd,
J
1
¼ 18.0 Hz, J
2
¼ 15.6 Hz, 2 H, 3-O-CO-CH
2
-), 3.61 (s, 1 H, H-11),
¼ 10.2 Hz, J ¼ 7.2 Hz,
eNH-), 2.88e2.82 (m,
0
3
1
3
.48e3.38 (m, 2 H, H-5 , 12-OH), 3.23 (dd, J
1
2
J ¼ 10.7 Hz, 1 H, H-3), 4.70 (d, J ¼ 10.9 Hz, 1 H, H-13), 4.38 (s, 1 H, H-
0
0
H, H-2 ), 3.10e2.90 (m, 2 H, 6-O-CO-CH
2
CH
2
5), 4.25 (d, J ¼ 5.6 Hz, 1 H, H-1 ), 3.98e3.87 (m, 2 H, 3-O-CO-CH
2
-),
0
H, H-2, -NH-CH
2
(CH
2
)
2
-Ar), 2.81e2.76 (m, 2 H, -NH-(CH
2
)
2
CH
2
-
3.61e3.51 (m, 2 H, H-11, 1 H-cyclopropyl), 3.51e3.31 (m, 4 H, H-5 ,
0
0
Ar), 2.74e2.52 (m, 5 H, H-10, 6-O-CO-CH
.44e2.38 (m, 1 H, H-9a), 2.36 (s, 3 H, -N-CH
N(CH ), 2.28e2.22 (m, 1 H, H-4), 2.04e1.94 (m, 3 H, H-9b, -NH-
2
CH
2
eNH-, H-3 , 11-OH),
12-OH, -CH
2
-NH-Ar), 3.22 (t, J ¼ 8.8 Hz, 1 H, H-2 ), 3.08e2.78 (m,
2
-
CH
1
(
1
CH
3
1
1
6
2
3
), 2.30 (s, 6 H,
5 H, -CH
10, H-3 , 11-OH, 6-O-CO-CH
2
CH
2
eNH-Ar, 6-O-CO-CH
-), 2.44e2.38 (m, 1 H, H-9a), 2.36 (s,
), 2.30 (s, 6 H, -N(CH ), 2.27e2.21 (m, 1 H, H-4),
2 2
CH -, H-2), 2.72e2.48 (m, 5 H, H-
0
3
)
2
2
2
CH
2
CH
2
-Ar), 1.94e1.85 (m, 2 H, H-14eq, H-7a), 1.81e1.73 (m,
3 H, -N-CH
3
3 2
)
0
H, H-8), 1.67e1.61 (m, 1 H, H-4 a), 1.60 (s, 3 H, 6-CH
m, 1 H, H-14ax), 1.39e1.32 (m, 1 H, H-7b), 1.27e1.20 (m, 1 H, H-4 b),
3
), 1.57e1.48
2.05e1.95 (m, 1 H, H-9b), 1.93e1.83 (m, 2 H, H-14eq, H-7a), 1.76 (s,
0
0
1 H, H-8), 1.68e1.47 (m, 5 H, H-4 a, 6-CH
3
, H-14ax), 1.41e1.30 (m,
0
0
.20e1.14 (m, 6 H, 5 -CH
3
, 4-CH
3
), 1.10e0.99 (m, 9 H, 12-CH
), 0.79 (t, J ¼ 7.3 Hz,
: 176.1, 172.0, 170.1, 154.0,
52.0, 149.2, 146.8, 136.6, 134.4, 134.2, 129.1, 128.6, 128.2, 127.4,
26.5, 124.1, 122.2, 103.2, 87.5, 79.4, 79.2, 78.3, 77.7, 77.3, 74.5, 70.8,
3
, 10-
3 H, H-7b, 2 H-cyclopropyl), 1.28e1.12 (m, 9 H, H-4 b, 2 H-cyclo-
0
3
, 2-CH
3
), 0.88 (d, J ¼ 6.9 Hz, 3 H, 8-CH
3
propyl, 5 -CH
3
, 4-CH
3
), 1.09e0.97 (m, 9 H, 10-CH
3
, 12-CH
3 3
, 2-CH ),
13
13
H, 15-CH
3
). C NMR (CDCl
3
, 100 MHz)
d
0.91e0.78 (m, 6 H, 8-CH
3
, 15-CH
3
). C NMR (CDCl , 100 MHz) d:
3
177.5,176.2,172.1,170.0,167.4,154.0,149.2,145.6,143.3,136.6,132.3,
127.7, 126.2, 124.1, 122.3, 117.9, 107.5, 104.3, 103.2, 87.2, 79.0, 78.3,
77.6, 77.3, 74.6, 70.8, 69.5, 65.5, 61.6, 47.4, 44.2, 44.0, 43.4, 42.7, 40.4,
40.3, 38.6, 36.8, 35.3, 28.7, 27.2, 21.3, 21.2, 21.1, 16.2, 16.1, 10.9, 9.3,
9.5, 65.5, 61.7, 48.7, 44.4, 44.0, 43.4, 40.4, 38.6, 36.7, 34.5. 30.7, 30.4,
8.7, 27.2, 21.2, 21.1, 16.5, 16.1, 10.8, 9.3, 8.0.

B.-Z. Fan et al. / European Journal of Medicinal Chemistry 193 (2020) 112222
23
8
.2, 8.1.
115.3, 109.9, 109.7, 107.8, 103.3, 95.6, 87.4, 79.4, 79.2, 78.4, 77.8, 77.2,
4.6, 70.8, 69.5, 65.6, 61.6, 48.7, 44.4, 44.0, 43.5, 43.0, 40.4, 40.4,
7
4
.3.18.8. 3-O-Descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-[3-({2-
38.6, 36.7, 35.3, 34.5, 28.7, 27.2, 26.8, 26.2, 21.2, 21.2, 16.4, 16.1, 10.8,
9.3, 8.2, 8.0.
[
(3-carboxy-7-chloro-1-cyclopropyl-1,4-dihydro-4-oxoquinolin-6-yl)
amino]propyl}amino)propanoyl]azithromycin (26h). Compound
6h (40.4 mg, 0.0370 mmol,15.4%) was prepared starting from 3-O-
descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-acryloylazithromycin
0.180 g, 0.240 mmol) and 6-(3-amino-propylamino)-7-chloro-1-
cyclopropyl-4-oxo-1,4-dihydroquinoline-3-carboxylic acid
0.0960 g, 0.300 mmol) according to the general procedure (column
2
4.3.18.10. 3-O-Descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-(3-{2-
[(3-carboxy-6-fluoro-1-cyclopropyl-1,4-dihydro-4-oxoquinolin-7-yl)
(
piperazin-1-yl]}propanoyl)azithromycin
(26j). Compound
26j
(48.7 mg, 0.0440 mmol, 25.9%) was prepared starting from 3-O-
descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-acryloylazithromycin
(0.130 g, 0.170 mmol) and ciprofloxacin (0.280 g, 0.850 mmol) ac-
(
chromatography eluents: CH
2
Cl
2
/MeOH/NH
3
‧H
2
O ¼ 10:0.7:0.5).
84ClN
: 8.70 (s, 1 H, H-quinolyl),
.51 (d, J ¼ 4.7 Hz, 1 H, H-pyridyl), 8.01 (s, 1 H, H-quinolyl), 7.67 (td,
¼ 7.7 Hz, J ¼ 1.8 Hz, 1 H, H-pyridyl), 7.47 (s, 1 H, H-quinolyl), 7.40
þ
HRMS (ESI) (M þ H) m/z 1099.5727, calcd for C56
H
6
O
14
cording to the general procedure (column chromatography eluents:
1
þ
1099.5729. H NMR (CDCl
3
, 400 MHz)
d
CH
1095.6022, calcd for C57
400 MHz) : 15.04 (s, 1 H, -COOH), 8.75 (s, 1 H, H-quinolyl), 8.51 (s,
2
Cl
2
/MeOH/NH
3
‧H
2
O ¼ 10:0.7:0.5). HRMS (ESI) (M þ H) m/z
1
8
6 3
H84FN O14 1095.6024. H NMR (CDCl ,
J
1
2
d
(
1
d, J ¼ 8 Hz, 1 H, H-pyridyl), 7.22e7.17 (m, 1 H, H-pyridyl), 5.90 (s,
1 H, H-pyridyl), 8.00 (d, J ¼ 13.0 Hz, 1 H, H-quinolyl), 7.68 (t,
J ¼ 7.9 Hz,1 H, H-pyridyl), 7.40 (d, J ¼ 8.0 Hz, 1 H, H-pyridyl), 7.35 (d,
J ¼ 7.0 Hz, 1 H, H-quinolyl), 7.24e7.17 (m, 1 H, H-pyridyl), 5.10 (d,
H, -NH-Ar), 5.08 (d, J ¼ 10.4 Hz, 1 H, H-3), 4.72 (d, J ¼ 10.8 Hz, 1 H,
0
H-13), 4.39 (d, J ¼ 3.0 Hz, 1 H, H-5), 4.25 (d, J ¼ 7.2 Hz, 1 H, H-1 ),
3
.94 (dd, J
1
¼17.6 Hz, J
2
¼ 16.0 Hz, 2 H, 3-O-CO-CH
2
-), 3.60 (s,1 H, H-
J ¼ 10.6 Hz, 1 H, H-3), 4.71 (d, J ¼ 10.6 Hz, 1 H, H-13), 4.34 (s, 1 H, H-
0
0
11), 3.58e3.51 (m, 1 H, 1 H-cyclopropyl), 3.50e3.35 (m, 4 H, H-5 ,
5), 4.26 (d, J ¼ 7.2 Hz, 1 H, H-1 ), 3.99e3.89 (m, 2 H, 3-O-CO-CH
2
-),
0
12-OH, -CH
2
-NH-Ar), 3.23 (dd, J
1
¼ 10.2 Hz, J
2
¼ 7.2 Hz, 1 H, H-2 ),
3.61 (s, 1 H, H-11), 3.53 (s, 1 H, 1 H-cyclopropyl), 3.49e3.31 (m, 6 H,
0
0
3
2
1
.06e2.79 (m, 5 H, 6-O-CO-CH
2
CH
2
eNHeCH
2
(CH
2
)
2
eNH-Ar, H-2),
-, H-3 , H-10, 11-OH), 2.47e2.40 (m,
H-5 , 12-OH, 4 H-piperazinyl), 3.25 (t, J ¼ 8.9 Hz, 1 H, H-2 ),
0
.73e2.51 (m, 5 H, 6-O-CO-CH
2
2.92e2.82 (m, 2 H, 6-O-CO-CH
2
CH
2
eN-), 2.82e2.60 (m, 7 H, H-2, H-
CH eNH-
), 2.33 (s, 6 H,
), 2.30e2.24 (m, 1 H, H-4), 2.08e1.99 (m, 1 H, H-9b),
0
H, H-9a), 2.37 (s, 3 H, -N-CH
3
), 2.30 (s, 6 H, -N(CH
3
)
2
), 2.28e2.24
10, 4 H-piperazinyl, H-3 ), 2.60e2.52 (m, 2 H, 6-O-CO-CH
2
2
(
m, 1 H, H-4), 2.06e1.96 (m, 1 H, H-9b), 1.95e1.85 (m, 4 H, H-14eq,
), 2.51e2.43 (m, 1 H, H-9a), 2.39 (s, 3 H, -N-CH
-N(CH
3
0
H-7a, -CH
2
CH
2
eNH-Ar), 1.78 (s, 1 H, H-8), 1.68e1.63 (m, 1 H, H-4 a),
3
)
2
1
7
2
.62 (s, 3 H, 6-CH
3
),1.58e1.48 (m,1 H, H-14ax),1.41e1.30 (m, 3 H, H-
1.98e1.87 (m, 2 H, H-14eq, H-7a), 1.87e1.78 (m, 1 H, H-8), 1.73e1.66
0
0
b, 2 H-cyclopropyl), 1.29e1.23 (m, 1 H, H-4 b), 1.23e1.13 (m, 8 H,
H-cyclopropyl, 5 -CH
(m, 1 H, H-4 a), 1.64 (s, 3 H, 6-CH
3
), 1.61e1.50 (m, 1 H, H-14ax),
0
0
3
, 4-CH
3
), 1.10e0.99 (m, 9 H, 2-CH
), 0.84 (t, J ¼ 7.3 Hz, 3 H, 15-
: 177.6, 176.3, 172.2, 170.0, 167.5,
3
, 10-CH
3
,
1.44e1.31 (m, 3 H, 2 H-cyclopropyl, H-7b), 1.30e1.13 (m, 9 H, H-4 b,
0
12-CH
3
), 0.89 (d, J ¼ 6.9 Hz, 3 H, 8-CH
3
5 -CH
3
, 4-CH
), 0.95e0.82 (m, 6 H, 8-CH
100 MHz)
3
, 2 H-cyclopropyl), 1.12e1.01 (m, 9 H, 10-CH
3
, 2-CH
3
,
,
13
13
CH
3
). C NMR (CDCl
3
, 100 MHz)
d
12-CH
3
3 3
, 15-CH ). C NMR (CDCl
3
1
1
6
2
54.0,149.3,145.5,143.5,136.6,132.1,127.5,126.3,124.1,122.3,117.8,
07.5, 103.9, 103.3, 87.2, 79.2, 79.1, 78.3, 77.2, 74.6, 70.8, 69.5, 65.6,
1.6, 47.8, 44.6, 44.0, 43.5, 42.8, 40.4, 36.8, 35.3, 34.8, 28.7, 27.8, 27.2,
1.3, 21.2, 21.1, 16.2, 16.1, 10.9, 9.3, 8.2, 8.1.
d
: 177.2, 176.3, 171.7, 170.0, 167.1, 154.9,154.0, 152.4, 149.3,
147.4, 146.0, 145.8, 139.1, 136.6, 124.2, 122.3, 119.7, 112.5, 112.3, 108.1,
104.7, 103.2, 87.2, 79.5, 79.0, 78.2, 77.7, 77.2, 74.7, 70.7, 69.4, 65.6,
61.6, 53.2, 52.5, 49.7, 44.0, 43.5, 40.4, 38.6, 36.9, 35.3, 32.9, 28.9,
27.3, 21.4, 21.2, 16.3, 16.1, 11.0, 9.3, 8.2.
4
[
.3.18.9. 3-O-Descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-[3-({2-
(3-carboxy-6-fluoro1-cyclopropyl-1,4-dihydro-4-oxo-quinolin-7-yl)
amino]butyl}amino)propanoyl]azithromycin (26i). Compound 26i
38.6 mg, 0.0350 mmol, 20.6%) was prepared starting from 3-O-
descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-acryloylazithromycin
0.130 g, 0.170 mmol) and 7-(4-amino-butylamino)-6-fluoro-1-
cyclopropyl-4-oxo-1,4-dihydroquinoline-3-carboxylic acid
0.110 g, 0.320 mmol) according to the general procedure (column
4.3.18.11. 3-O-Descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-(3-{2-
[(3-carbamoyl-6-fluoro-1-cyclopropyl-1,4-dihydro-4-oxoquinolin-7-
yl)piperazin-1-yl]}propanoyl)azithromycin (26k). Compound 26k
(35.2 mg, 0.0320 mmol, 10.7%) was prepared starting from 3-O-
descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-acryloylazithromycin
(0.300 g, 0.390 mmol) and compound 20 (0.0940 g, 0.300 mmol)
according to the general procedure (column chromatography elu-
(
(
(
chromatography eluents: CH
HRMS (ESI) (M þ H) m/z 1097.6191, calcd for C57
2
Cl
2
/MeOH/NH
3
‧H
2
O ¼ 10:0.7:0.5).
ents: CH
2
Cl
2
/EtOH/NH
3
‧H
2
O
¼
10:0.2:0.05). Melting point:
þ
ꢀ
þ
H86FN
6
O
14
139e141 C. HRMS (ESI) (M þ H) m/z 1094.6187, calcd for
1
1
1
8
097.6181. H NMR (CDCl
.50 (s, 1 H, H-pyridyl), 7.87 (d, J ¼ 11.5 Hz, 1 H, H-quinolyl), 7.66 (t,
J ¼ 8.0 Hz, 1 H, H-pyridyl), 7.37 (d, J ¼ 7.6 Hz, 1 H, H-pyridyl),
.22e7.16 (m, 1 H, H-pyridyl), 6.95 (d, J ¼ 6.9 Hz, 1 H, H-quinolyl),
3
, 400 MHz)
d: 8.67 (s, 1 H, H-quinolyl),
C
57
H85FN
7
O
13 1094.6184. H NMR (CDCl
J ¼ 5.3 Hz,1 H, -NH ), 8.80 (s, 1 H, H-quinolyl), 8.54e8.49 (m,1 H, H-
pyridyl), 8.01 (d, J ¼ 13.3 Hz, 1 H, H-quinolyl), 7.68 (td, J ¼ 7.7 Hz,
¼ 1.8 Hz, 1 H, H-pyridyl), 7.40 (d, J ¼ 7.8 Hz, 1 H, H-pyridyl), 7.31
(d, J ¼ 7.1 Hz, 1 H, H-quinolyl), 7.21 (ddd, J ¼ 7.5 Hz, J ¼ 4.8 Hz,
), 5.10 (d,
3
, 400 MHz) d: 9.72 (d,
2
1
7
5
J
2
.69 (s, 1 H, -NH-Ar), 5.07 (d, J ¼ 10.6 Hz, 1 H, H-3), 4.74 (d,
1
2
J ¼ 10.7 Hz, 1 H, H-13), 4.39 (s, 1 H, H-5), 4.25 (d, J ¼ 6.4 Hz, 1 H, H-
J
3
¼ 1.1 Hz, 1 H, H-pyridyl), 5.77 (d, J ¼ 5.3 Hz, 1 H, -NH
2
0
1
(
), 3.99e3.89 (m, 2 H, 3-O-CO-CH
2
-), 3.60 (s, 1 H, H-11), 3.56e3.37
J ¼ 10.6 Hz, 1 H, H-3), 4.72 (d, J ¼ 10.4 Hz, 1 H, H-13), 4.35 (s, 1 H, H-
0
0
m, 3 H, 1 H-cyclopropyl, H-5 , 12-OH), 3.32e3.19 (m, 3 H, -CH
Ar, H-2 ), 3.05e2.50 (m, 10 H, H-2, -CH
2
-NH-
5), 4.26 (d, J ¼ 7.2 Hz, 1 H, H-1 ), 3.94 (dd, J
1
¼ 18.4 Hz, J ¼ 16.0 Hz,
2
0
2
(CH
2
)
3
eNH-Ar, 11-OH, 6-O-
2 H, 3-O-CO-CH
2
0
-), 3.61 (s, 1 H, H-11), 3.51e3.41 (m, 3 H, 1 H-
0
0
CO-CH
CH
H, H-9b, H-14eq, H-7a, -NH-(CH
m, 3 H, -NH-CH CH (CH
H-4 a), 1.60 (s, 3 H, 6-CH
2
CH
2
-, H-10, H-3 ), 2.48e2.38 (m, 1 H, H-9a), 2.36 (s, 3 H, -N-
cyclopropyl, H-5 , 12-OH), 3.37e3.23 (m, 5 H, 4 H-piperazinyl, H-2 ),
3
), 2.30 (s, 6 H, -N(CH
3
)
2
), 2.27e2.21 (m, 1 H, H-4), 2.05e1.81 (m,
CH CH eNH-Ar), 1.79e1.69
2.91e2.83 (m, 2 H, 6-O-CO-CH
H-10, 4 H-piperazinyl, 6-O-CO-CH
1 H, H-9a), 2.38 (s, 3 H, -N-CH
(m, 1 H, H-4), 2.07e1.98 (m, 1 H, H-9b), 1.96e1.88 (m, 2 H, H-14eq,
H-7a), 1.86e1.78 (m, 1 H, H-8), 1.75e1.67 (m, 1 H, H-4 a), 1.63 (s, 3 H,
2
CH
2
eNH-), 2.82e2.54 (m, 9 H, H-2,
0
5
(
2
)
2
2
2
2
CH
2
eNH-, H-3 ), 2.50e2.43 (m,
2
2
2
)
2
eNH-Ar, H-8), 1.65 (d, J ¼ 12.9 Hz, 1 H,
3
), 2.35 (s, 6 H, -N(CH
3
)
2
), 2.32e2.27
0
3
), 1.58e1.48 (m, 1 H, H-14ax), 1.40e1.30
0
0
(
m, 3 H, H-7b, 2 H-cyclopropyl), 1.29e1.13 (m, 9 H, H-4 b, 2 H-
0
cyclopropyl, 5 -CH
CH
), 0.88 (d, J ¼ 6.7 Hz, 3 H, 8-CH
C NMR (CDCl , 100 MHz) : 176.7, 176.1, 172.2, 170.1, 167.6, 154.0,
51.5, 149.2, 149.0, 146.6, 142.8, 142.7, 140.4, 136.6, 124.1, 122.3,
3
, 4-CH
3
), 1.09e0.98 (m, 9 H, 10-CH
3
, 12-CH
3
, 2-
6-CH
propyl, H-7b), 1.29e1.23 (m, 1 H, H-4 b), 1.22e1.13 (m, 8 H, 5 -CH
4-CH , 2 H-cyclopropyl), 1.11e1.03 (m, 9 H, 10-CH , 2-CH , 12-CH
0.91 (d, J ¼ 6.9 Hz, 3 H, 8-CH ), 0.86 (t, J ¼ 7.3 Hz, 3 H, 15-CH
3
), 1.59e1.51 (m, 1 H, H-14ax), 1.38e1.29 (m, 3 H, 2 H-cyclo-
0
0
3
3
), 0.84e0.77 (m, 3 H, 15-CH
3
).
3
,
1
3
3
d
3
3
3
3
),
C
1
3
1
3
3
).

24
B.-Z. Fan et al. / European Journal of Medicinal Chemistry 193 (2020) 112222
NMR (CDCl
54.0, 152.2, 149.3, 147.1, 145.0, 144.9, 138.6, 136.6, 124.2, 122.3,
21.8, 121.7, 112.8, 112.6, 111.0, 104.7, 103.1, 87.1, 79.6, 79.0, 78.3, 77.7,
3
, 100 MHz)
d
: 176.3, 175.4, 171.8, 170.0, 166.8, 154.7,
1.96e1.88 (m, 2 H, H-14eq, H-7a), 1.86e1.80 (m, 1 H, H-8), 1.70e1.65
0
1
1
(m, 1 H, H-4 a), 1.64 (s, 3 H, 6-CH
3
), 1.58 (t, J ¼ 7.1 Hz, 3 H, -CH
2 3
CH ),
1.55e1.51 (m, 1 H, H-14ax), 1.35 (dd, J
1
¼14.1 Hz, J
2
¼ 5.6 Hz, 1 H, H-
0
0
7
3
7.2, 74.7, 70.7, 69.4, 65.6, 61.6, 53.2, 52.6, 49.8, 44.0, 43.5, 40.4, 36.9,
4.7, 32.9, 27.3, 21.3, 21.2, 16.1, 11.0, 9.3, 8.2.
7b), 1.27e1.21 (m, 1 H, H-4 b), 1.21e1.14 (m, 6 H, 5 -CH
3
, 4-CH
3
),
1.10e1.02 (m, 9 H, 10-CH
3
, 2-CH
3
, 12-CH
3
), 0.90 (d, J ¼ 6.9 Hz, 3 H, 8-
13
CH
3
), 0.86 (t, J ¼ 7.3 Hz, 3 H, 15-CH
3 3
). C NMR (CDCl , 100 MHz) d:
4
.3.18.12. 3-O-Descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-(3-{2-
177.0, 176.3, 171.7, 170.0, 167.3, 154.8, 154.0, 149.3, 147.0, 137.1, 136.6,
124.1, 122.3, 112.9, 112.7, 108.4, 103.6, 103.2, 87.2, 79.4, 79.0, 78.3,
77.7, 77.2, 74.7, 70.7, 69.5, 65.6, 61.6, 53.2, 52.5, 49.8, 44.0, 43.5, 40.4,
36.9, 32.9, 27.3, 21.4, 21.2, 21.1, 16.1, 14.5, 11.0, 9.3, 8.3.
[
3-(3-carboxy-6-fluoro-8-methoxy-1-cyclopropyl-1,4-dihydro-4-
oxoquinolin-7-yl)methylpiperazin-1-yl]}propanoyl)azithromycin
26l). Compound 26l (36.7 mg, 0.0320 mmol, 12.3%) was prepared
(
starting from 3-O-descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-
acryloylazithromycin (0.200 g, 0.260 mmol) and gatifloxacin
4.3.18.14. 3-O-Descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-(3-{2-
(
0.120 g, 0.310 mmol) according to the general procedure (column
[(3-carboxy-6-fluoro-1-ethyl-1,4-dihydro-1,8-naphthyridine-4-
chromatography eluents: CH
2
Cl
2
/MeOH/NH
3
‧H
2
O ¼ 10:0.8:0.5).
oxoquinolin-7-yl)piperazin-1-yl]}propanoyl)azithromycin
(26n).
ꢀ
þ
Melting point: 147e150 C. HRMS (ESI) (M þ H) m/z 1139.6264,
Compound 26n (34.4 mg, 0.0320 mmol, 24.6%) was prepared
starting from 3-O-descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-
acryloylazithromycin (0.100 g, 0.130 mmol) and enoxacin (0.0500 g,
0.160 mmol) according to the general procedure (column chro-
1
calcd for C59
6 3
H88FN O15 1139.6286. H NMR (CDCl , 700 MHz) d: 8.80
(
s, 1 H, H-quinolyl), 8.52 (d, J ¼ 2.8 Hz, 1 H, H-pyridyl), 7.85 (dd,
J
1
¼ 12.0 Hz, J ¼ 2.7 Hz, 1 H, H-quinolyl), 7.70e7.66 (m, 1 H, H-
2
pyridyl), 7.41 (d, J ¼ 7.9 Hz, 1 H, H-pyridyl), 7.21 (t, J ¼ 6.2 Hz, 1 H, H-
matography eluents: CH
2
Cl
2
/MeOH/NH
3
‧H
2
O ¼ 10:0.8:0.5). Melting
ꢀ
þ
pyridyl), 5.10 (t, J ¼ 8.4 Hz, 1 H, H-3), 4.67 (t, J ¼ 9.1 Hz, 1 H, H-13),
point: 137e140 C. HRMS (ESI) (M þ H) m/z 1084.5987, calcd for
0
1
4
4
.37 (d, J ¼ 17.4 Hz, 1 H, H-5), 4.27 (d, J ¼ 7.4 Hz, 1 H, H-1 ),
.05e4.00 (m, 1 H, 1 H-cyclopropyl), 3.98e3.90 (m, 2-H, 3-O-CO-
C
55
H83FN
7
O
14 1084.5977. H NMR (CDCl
-COOH), 8.68 (s, 1 H, H-quinolyl), 8.52 (dd, J
1 H, H-pyridyl), 8.08 (d, J ¼ 13.4 Hz, 1 H, H-quinolyl), 7.68 (td,
¼ 7.7 Hz, J ¼ 1.9 Hz, 1 H, H-pyridyl), 7.39 (d, J ¼ 7.8 Hz, 1 H, H-
pyridyl), 7.21 (dd, J
3
, 400 MHz)
d: 15.09 (s, 1 H,
1
¼ 5.1 Hz, J
2
¼ 1.7 Hz,
CH
2
-), 3.74 (d, J ¼ 4.4 Hz, 3 H, Ar-O-CH
3
), 3.61 (s, 1 H, H-11),
0
3
.61e3.56 (m, 1 H, 12-OH), 3.50e3.38 (m, 4 H, H-5 , 3 H-piper-
J
1
2
0
azinyl), 3.25 (t, J ¼ 8.8 Hz, 1 H, H-2 ), 3.21e3.12 (m, 1 H, 1 H-
1
¼ 7.6 Hz, J ¼ 4.9 Hz, 1 H, H-pyridyl), 5.10 (d,
2
piperazinyl), 3.10e3.04 (m, 1 H, 1 H-piperazinyl), 3.02e2.92 (m, 2 H,
J ¼ 10.7 Hz, 1 H, H-3), 4.71 (d, J ¼ 10.6 Hz, 1 H, H-13), 4.40 (m, 2 H,
0
6
2
-O-CO-CH
2
CH
2
eNH-), 2.91e2.83 (m, 2 H, H-2, 1 H-piperazinyl),
-CH
2
CH
3
), 4.30 (s, 1 H, H-5), 4.26 (d, J ¼ 7.2 Hz, 1 H, H-1 ), 3.99e3.92
0
.75e2.60 (m, 5 H, H-10, H-3 , 6-O-CO-CH
2
CH
2
eNH-, 1 H-piper-
), 2.33 (s, 6 H,
), 2.30e2.27 (m, 1 H, H-4), 2.05e1.99 (m, 1 H, H-9b),
.96e1.88 (m, 2 H, H-14eq, H-7a), 1.85e1.78 (m, 1 H, H-8), 1.71e1.66
(m, 2 H, 3-O-CO-CH
2
-), 3.92e3.84 (m, 4 H, 4 H-piperazinyl),
0
azinyl), 2.56e2.46 (m, 1 H, H-9a), 2.39 (s, 3 H, -N-CH
N(CH
3
3.82e3.71 (m, 1 H, 2 -OH), 3.60 (s, 1 H, H-11), 3.51e3.41 (m, 2 H, H-
0
0
-
1
3
)
2
5 , 12-OH), 3.25 (dd, J
1
¼ 10.2 Hz, J
2
¼ 7.2 Hz, 1 H, H-2 ), 2.91e2.79
(m, 3 H, 6-O-CO-CH
2
CH
2
eNH-, H-2), 2.77e2.50 (m, 8 H, H-10, 4 H-
0
0
(
m, 1 H, H-4 a), 1.64 (s, 3 H, 6-CH
3
), 1.59e1.53 (m, 1 H, H-14ax),
piperazinyl, H-3 , 6-O-CO-CH
2
CH
2
eNH-), 2.48e2.42 (m, 1 H, H-9a),
), 2.30e2.25 (m,1 H, H-4),
0
1.38e1.32 (m, 1 H, H-7b), 1.28e1.19 (m, 6 H, H-4 b, 2 H-cyclopropyl,
2.37 (s, 3 H, -N-CH
3
), 2.33 (s, 6 H, -N(CH )
3 2
0
piperazinyl-CH
3
), 1.18e1.13 (m, 6 H, 5 -CH
, 2-CH ), 1.02e0.96 (m, 2 H, 2 H-
cyclopropyl), 0.94e0.89 (m, 3 H, 8-CH
), 0.87 (t, J ¼ 7.4 Hz, 3 H, 15-
: 177.0, 177.0, 176.4, 172.1, 172.0,
70.0, 169.9, 166.8, 156.7, 155.3, 154.0, 149.8, 149.2, 145.1, 139.6,
36.6, 134.0, 124.2, 122.3, 121.5, 108.2, 108.0, 107.7, 103.2, 87.0, 79.3,
9.0, 78.3, 77.6, 74.7, 70.7, 69.4, 65.6, 62.6, 61.5, 57.5, 55.0, 54.9, 51.5,
1.1, 50.9, 48.8, 48.5, 44.0, 43.5, 40.5, 40.4, 38.5, 36.9, 31.6, 31.5, 28.8,
3
, 4-CH
3
), 1.09 (s, 3 H, 12-
2.07e1.99 (m, 1 H, H-9b), 1.96e1.87 (m, 2 H, H-14eq, H-7a),
0
CH
3
), 1.08e1.03 (m, 6 H, 10-CH
3
3
1.86e1.80 (m, 1 H, H-8), 1.72e1.66 (m, 1 H, H-4 a), 1.63 (s, 3 H, 6-
3
CH
-CH
3
), 1.59e1.53 (m, 1 H, H-14ax), 1.49 (t, J ¼ 7.1 Hz, 3 H,
13
CH
3
). C NMR (CDCl
3
, 175 MHz)
d
2
CH
3
), 1.35 (dd, J
1
¼ 14.1 Hz, J
2
¼ 5.7 Hz, 1 H, H-7b), 1.26 (t,
0
0
1
1
7
5
J ¼ 11.9 Hz, 1 H, H-4 b), 1.19 (d, J ¼ 6.1 Hz, 3 H, 5 -CH
3
), 1.16 (d,
J ¼ 7.4 Hz, 3 H, 4-CH
0.90 (d, J ¼ 6.9 Hz, 3 H, 8-CH
NMR (CDCl , 100 MHz)
150.4, 149.3, 148.7, 146.3, 146.1, 145.1, 136.6, 124.2, 122.3, 120.2,
20.0, 113.7, 109.3, 103.1, 87.2, 79.5, 79.0, 78.2, 77.7, 77.2, 74.6, 70.7,
3
), 1.11e1.01 (m, 9 H, 10-CH
3
, 2-CH
3
, 12-CH
3
),
C
1
3
3
), 0.86 (t, J ¼ 7.4 Hz, 3 H, 15-CH
3
).
3
d: 177.1, 176.3, 171.7, 170.0, 167.1, 154.0, 150.5,
27.2, 21.4, 21.2, 21.1, 21.1, 16.1, 15.8, 15.7, 11.0, 9.6, 9.4, 9.3, 8.2.
1
4
.3.18.13. 3-O-Descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-(3-{2-
69.4, 65.6, 61.6, 53.1, 52.7, 47.8, 47.0, 46.9, 44.0, 43.5, 40.4, 36.9, 32.9,
27.3, 21.4, 21.2, 16.1, 15.0, 11.0, 9.3, 8.3.
[
(3-carboxy-6-fluoro-1-ethyl-1,4-dihydro-4-oxoquinolin-7-yl)piper-
azin-1-yl]}propanoyl)azithromycin (26m). Compound 26m
24.1 mg, 0.0220 mmol, 16.9%) was prepared starting from 3-O-
descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-acryloylazithromycin
0.100 g, 0.130 mmol) and norfloxacin (0.0500 g, 0.160 mmol) ac-
(
4.3.18.15. 3-O-Descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-(3-{[4-
(quinolin-6-yl)but-3-yn-1-yl]amino}propanoyl)azithromycin (26o).
Compound 26o (20.5 mg, 0.0210 mmol, 4.67%) was prepared
starting from 3-O-descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-
acryloylazithromycin (0.340 g, 0.450 mmol) and compound 11b
(0.0880 g, 0.450 mmol) according to the general procedure (column
(
cording to the general procedure (column chromatography eluents:
CH
ꢀ
2
Cl
2
/MeOH/NH
3
‧H
2
O ¼ 10:1:0.5). Melting point: 144e147 C.
þ
HRMS (ESI) (M þ H) m/z 1083.6035, calcd for C56
6 14
H84FN O
: 15.14 (s, 1 H, -COOH), 8.67
1
1
(
083.6024. H NMR (CDCl
s, 1 H, H-quinolyl), 8.51 (d, J ¼ 4.0 Hz, 1 H, H-pyridyl), 8.05 (d,
J ¼ 13.1 Hz, 1 H, H-quinolyl), 7.67 (td, J ¼ 7.7 Hz, J ¼ 1.9 Hz, 1 H, H-
¼ 7.6 Hz,
3
, 400 MHz)
d
chromatography eluents: CH
2
Cl
2
/EtOH/NH
3
‧H
2
O ¼ 10:0.3:0.05).
þ
HRMS (ESI) (M þ H) m/z 960.5693, calcd for C53
78 5 11
H N O
1
1
2
960.5692. H NMR (CDCl
3
, 400 MHz)
d: 8.88 (dd, J
1
¼ 4.2 Hz,
pyridyl), 7.40 (d, J ¼ 7.8 Hz, 1 H, H-pyridyl), 7.20 (dd, J
1
J
2
¼ 1.7 Hz, 1 H, H-quinolyl), 8.51 (dd, J
1
¼ 5.0 Hz, J ¼ 0.9 Hz, 1 H, H-
2
J
2
¼ 4.9 Hz, 1 H, H-pyridyl), 6.82 (d, J ¼ 6.7 Hz, 1 H, H-quinolyl), 5.10
pyridyl), 8.08 (dd, J
1
¼ 8.3 Hz, J ¼ 1.7 Hz, 1 H, H-quinolyl), 7.99 (d,
2
(
d, J ¼ 10.4 Hz, 1 H, H-3), 4.70 (d, J ¼ 10.6 Hz, 1 H, H-13), 4.32 (s, 1 H,
J ¼ 8.7 Hz, 1 H, H-quinolyl), 7.89 (d, J ¼ 1.7 Hz, 1 H, H-quinolyl),
0
H-5), 4.37e4.27 (m, 2 H, -CH
2
CH
3
), 4.25 (d, J ¼ 7.2 Hz, 1 H, H-1 ),
7.72e7.64 (m, 2 H, H-quinolyl, H-pyridyl), 7.43e7.34 (m, 2 H, H-
3
2
.98e3.89 (m, 2 H, 3-O-CO-CH
2
-), 3.60 (s, 1 H, H-11), 3.50e3.41 (m,
quinolyl, H-pyridyl), 7.19 (ddd, J
1 H, H-pyridyl), 5.12 (dd, J
1
¼ 7.6 Hz, J
2
¼ 4.9 Hz, J ¼ 1.2 Hz,
3
0
H, H-5 , 12-OH), 3.40e3.30 (m, 4 H, 4 H-piperazinyl), 3.24 (dd,
1
¼ 10.6 Hz, J ¼ 2.0, 1 H, H-3), 4.78 (dd,
2
0
J
1
¼ 10.2 Hz, J
2
¼ 7.2 Hz, 1 H, H-2 ), 2.91e2.60 (m, 10 H, 6-O-CO-
J
1
¼10.8 Hz, J
2
¼ 2.0, 1 H, H-13), 4.32 (d, J ¼ 3.0 Hz,1 H, H-5), 4.24 (d,
0
0
CH CH
2
2
eNH-, H-2, H-10, 4 H-piperazinyl), 2.58e2.52 (m, 2 H, H-3 ,
J ¼ 7.2 Hz, 1 H, H-1 ), 3.94 (dd, J
1
¼16 Hz, J
2
¼ 15.6 Hz, 2 H, 3-O-CO-
0
11-OH), 2.50e2.44 (m, 1 H, H-9a), 2.38 (s, 3 H, -N-CH
3
), 2.31 (s, 6 H,
CH
2
-), 3.60 (s, 1 H, H-11), 3.47e3.40 (m, 2 H, H-5 , 12-OH), 3.24 (dd,
0
-
N(CH ), 2.30e2.26 (m, 1 H, H-4), 2.06e1.99 (m, 1 H, H-9b),
3
)
2
J
1
¼ 10.2 Hz, J
2
¼ 7.2 Hz, 1 H, H-2 ), 3.16e2.80 (m, 5 H, 6-O-CO-

B.-Z. Fan et al. / European Journal of Medicinal Chemistry 193 (2020) 112222
25
0
CH
CH
2
CH
2
eNHeCH
eNHeCH
2
CH
CH
2
C≡CeAr, H-2), 2.79e2.59 (m, 7 H, 6-O-CO-
1 H, H-11), 3.54e3.45 (m, 2 H, H-5 , 12-OH), 3.23 (dd, J
1
¼ 10.2 Hz,
0
0
2
CH
2
2
2
C≡CeAr, H-10, H-3 11-OH), 2.44e2.38 (m,
J
2
¼
7.2 Hz,
eNHeCH
1
H, H-2 ), 3.15e2.88 (m,
C≡CeAr, 11-OH), 2.88e2.80 (m, 1 H, H-2),
5
H, 6-O-CO-
1
H, H-9a), 2.37 (s, 3 H, -N-CH
3
), 2.31 (s, 6 H, -N(CH
3
)
2
), 2.29e2.25
CH
2
CH
2
2
CH
2
(
1
1
1
3
3
1
1
8
4
m, 1 H, H-4), 2.00 (t, J ¼ 11.5 Hz, 1 H, H-9b), 1.94e1.80 (m, 3 H, H-
2.72e2.54 (m, 6 H, 6-O-CO-CH
3 ), 2.47e2.40 (m, 1 H, H-9a), 2.36 (s, 3 H, -N-CH
2
CH
2
eNHeCH
2
CH
2
C≡CeAr, H-10, H-
), 2.28 (s, 6 H,
), 2.27e2.22 (m, 1 H, H-4), 2.01 (dd, J
0
0
4eq, H-7a, H-8), 1.69e1.63 (m, 1 H, H-4 a), 1.62 (s, 3 H, 6-CH
3
),
3
.58e1.46 (m,1 H, H-14ax),1.35 (dd, J
.25e1.21 (m, 1 H, H-4 b), 1.18e1.14 (m, 6 H, 5 -CH
1
¼14.0 Hz, J
2
¼ 6.2,1 H, H-7b),
-N(CH
3
)
2
1
¼ 12.8 Hz,
0
0
3
, 4-CH ), 1.07 (s,
3
J
2
¼ 10.1 Hz, 1 H, H-9b), 1.95e1.85 (m, 2 H, H-14eq, H-7a), 1.80e1.72
0
H, 12-CH
3
), 1.06e1.02 (m, 6 H, 10-CH
), 0.80 (t, J ¼ 7.3 Hz, 3 H, 15-CH
: 176.0, 171.9, 170.0, 154.0, 150.6, 149.2, 147.4, 136.6,
35.6, 132.5,130.9,129.4,128.0,124.2, 122.3,122.1, 121.6,103.2, 89.3,
3
, 2-CH
3
), 0.86 (d, J ¼ 6.8 Hz,
(m, 1 H, H-8), 1.68e1.62 (m, 1 H, H-4 a), 1.58 (s, 3 H, 6-CH
3
),
13
H, 8-CH
3
3
). C NMR (CDCl
3
,
1.56e1.50 (m, 1 H, H-14ax), 1.34 (dd, J
1
¼14.1 Hz, J ¼ 6.1 Hz, 1 H, H-
2
0
0
75 MHz)
d
7b), 1.25e1.20 (m, 1 H, H-4 b), 1.19e1.14 (m, 6 H, 5 -CH
3
, 4-CH
), 0.88 (d, J ¼ 6.9 Hz, 3 H, 8-
3
3
),
1.09e1.01 (m, 9 H, 2-CH
CH
176.1, 172.5,170.3,166.8,154.2,153.8,149.4, 147.4, 137.8,136.7, 128.5,
124.1, 122.4, 120.6, 103.6, 93.2, 87.4, 79.9, 79.0, 78.3, 78.0, 77.9, 77.3,
3 3 3
,12-CH ,10-CH
), 0.81 (t, J ¼ 7.3 Hz, 3 H, 15-CH
1
7.4, 81.4, 79.6, 79.0, 78.1, 77.9, 74.5, 70.7, 69.4, 65.5, 61.8, 48.0, 44.2,
4.0, 43.4, 40.4, 38.7, 36.8, 35.1, 28.8, 27.4, 21.2, 21.2, 21.0, 20.2, 16.3,
6.1, 10.8, 9.3, 8.2.
3
3 3
). C NMR (CDCl , 100 MHz) d:
1
74.6, 70.8, 69.5, 65.5, 61.7, 47.7, 44.4, 43.7, 43.5, 40.3, 38.5, 36.9, 35.4,
4
.3.18.16. 3-O-Descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-(3-{[4-
28.6, 27.3, 21.2, 21.2, 20.5, 16.4, 16.0, 10.9, 9.3, 8.2.
(
1,4-dihydro-4-oxo-quinolin-6-yl)but-3-yn-1-yl]amino}propanoyl)
azithromycin (26p). Compound 26p (38.6 mg, 0.0400 mmol, 12.9%)
was prepared starting from 3-O-descladinosyl-3-O-[2-(2-pyridyl)
acetyl]-6-O-acryloylazithromycin (0.300 g, 0.390 mmol) and com-
pound 11c (0.0650 g, 0.310 mmol) according to the general pro-
4.3.18.18. 3-O-Descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-(3-{[4-
(3-carbamoyl-1-cyclopropyl-1,4-dihydro-4-oxoquinolin-6-yl)but-3-
yn-1-yl]amino}propanoyl)azithromycin
(26r). Compound
26r
(84.3 mg, 0.0800 mmol, 20.5%) was prepared starting from 3-O-
descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-acryloylazithromycin
(0.300 g, 0.390 mmol) and compound 11e (0.200 g, 0.680 mmol)
according to the general procedure (column chromatography elu-
cedure (column chromatography eluents: CH
2
Cl
2
/MeOH/NH
3
‧
ꢀ
þ
H
2
O ¼ 10:1.5:0.1). Melting point: 132e135 C. HRMS (ESI) (M þ H)
1
m/z 976.5631, calcd for C53
00 MHz) : 8.51e8.45 (m, 1 H, H-pyridyl), 8.28 (s, 1 H, H-quinolyl),
.86e7.75 (m, 1 H, H-quinolyl), 7.66 (td, J ¼ 1.9 Hz, 1 H,
¼ 7.7 Hz, J
H-pyridyl), 7.51e7.43 (m, 1 H, H-quinolyl), 7.41e7.34 (m, 2 H, H-
quinolyl, H-pyridyl), 7.19 (ddd, J
78 5 3
H N O12 976.5641. H NMR (CDCl ,
4
7
d
ents: CH
2
Cl
2
/EtOH/NH
3
‧H
2
O
¼
10:0.3:0.05). Melting point:
ꢀ
þ
1
2
143e147 C. HRMS (ESI) (M þ H) m/z 1059.6023, calcd for
1
C
57
83
H N
6
O
13 1059.6013. H NMR (CDCl
J ¼ 5.2 Hz, 1 H, -NH ), 8.83 (s, 1 H, H-quinolyl), 8.52 (d, J ¼ 4.9 Hz,
1 H, H-pyridyl), 8.44 (d, J ¼ 1.9 Hz, 1 H, H-quinolyl), 7.90 (d,
J ¼ 8.8 Hz, 1 H, H-quinolyl), 7.76 (dd, J ¼ 8.8 Hz, J ¼ 2.0 Hz, 1 H, H-
quinolyl), 7.68 (td, J ¼ 1.9 Hz, 1 H, H-pyridyl), 7.40 (d,
¼ 7.7 Hz, J
J ¼ 7.8 Hz, 1 H, H-pyridyl), 7.21 (ddd, J ¼ 7.6 Hz, J ¼ 4.9 Hz,
), 5.10 (d,
3
, 400 MHz) d: 9.61 (d,
1
¼ 7.6 Hz, J
2
¼ 4.9 Hz, J
3
¼ 1.1 Hz,
2
1
1
4
3
3
H, H-pyridyl), 6.38e6.16 (m, 1 H, H-quinolyl), 5.05 (d, J ¼ 10.7 Hz,
H, H-3), 4.84e4.61 (m, 1 H, H-13), 4.41 (d, J ¼ 2.8 Hz, 1 H, H-5),
1
2
0
.22 (d, J ¼ 7.2 Hz, 1 H, H-1 ), 3.93 (dd, J
1
¼18.0 Hz, J
2
¼ 16.0 Hz, 2 H,
1
2
0
-O-CO-CH
.22 (dd, J
2
-), 3.55 (s, 1 H, H-11), 3.47e3.37 (m, 2 H, H-5 , 12-OH),
1
2
0
1
¼10.2 Hz, J
2
¼ 7.1 Hz, 1 H, H-2 ), 3.18e2.92 (m, 4 H, 6-O-
J
3
¼ 1.1 Hz, 1 H, H-pyridyl), 5.82 (d, J ¼ 5.2 Hz, 1 H, -NH
2
CO-CH
2
CH
CH
2
eNHeCH
eNHeCH
2
CH
2
C≡CeAr, H-2), 2.86e2.56 (m, 7 H, 6-O-
J ¼ 10.6 Hz, 1 H, H-3), 4.85 (d, J ¼ 10.7 Hz, 1 H, H-13), 4.40 (s, 1 H, H-
0
0
CO-CH
2
2
2
CH
2
C≡CeAr, H-10, H-3 ), 2.39e2.34 (m, 1 H,
5), 4.25 (d, J ¼ 7.2 Hz, 1 H, H-1 ), 3.95 (dd, J
1
¼ 20.8 Hz, J ¼ 16.0 Hz,
2
H-9a), 2.28 (s, 9 H, -N-CH
3
, -N(CH
3
)
2
), 2.52e2.20 (m, 1 H, H-4),
2 H, 3-O-CO-CH
2
-), 3.62 (s, 1 H, H-11), 3.53e3.41 (m, 3 H, 1 H-
0
0
2
.03e1.90 (m, 2 H, H-9b, H-14eq), 1.87e1.78 (m, 1 H, H-7a),
cyclopropyl, H-5 , 12-OH), 3.27 (t, J ¼ 8.7 Hz, 1 H, H-2 ), 3.22e2.98
0
1.76e1.67 (m, 1 H, H-8), 1.66e1.62 (m, 1 H, H-4 a), 1.59 (s, 3 H, 6-
(m, 5 H, 6-O-CO-CH
(m, 7 H, 6-O-CO-CH CH
2.42e2.32 (m, 10 H, H-9a, -N-CH
2
CH
eNHeCH
, -N(CH
2
eNHeCH
2
CH
2
C≡CeAr, H-2), 2.88e2.61
0
CH
3
), 1.51e1.38 (m, 1 H, H-14ax), 1.32 (dd,
J
1
¼ 13.7 Hz,
2
2
2
CH
2
C≡CeAr, H-10, H-3 , 11-OH),
0
J
5
2
¼ 5.7 Hz, 1 H, H-7b), 1.27e1.19 (m, 1 H, H-4 b), 1.17e1.10 (m, 6 H,
3
3
)
2
), 2.28e2.21 (m, 1 H, H-
0
-CH
3
, 4-CH
3
), 1.06e0.92 (m, 9 H, 2-CH
3
, 12-CH
3
, 10-CH
3
),
4), 2.06e1.96 (m, 1 H, H-9b), 1.94e1.83 (m, 2 H, H-14eq, H-7a),
13
0
0
.88e0.80 (m, 6 H, 8-CH
3
, 15-CH
3
). C NMR (CDCl , 100 MHz)
3
d:
1.82e1.75 (m, 1 H, H-8), 1.74e1.67 (m, 1 H, H-4 a), 1.59 (s, 3 H, 6-
1
1
7
4
78.2, 175.8, 172.1, 170.2, 153.9, 149.2, 139.4, 139.3, 136.7, 134.6,
29.0, 125.6, 124.2, 122.4, 119.1, 118.5, 109.6, 103.2, 87.4, 81.3, 79.3,
8.9, 78.4, 78.0, 77.2, 74.6, 70.8, 69.5, 65.5, 61.7, 48.1, 44.3, 43.9, 43.4,
0.4, 38.6, 36.8, 35.0, 28.7, 27.2, 21.2, 20.2, 16.5, 16.0, 10.7, 9.3, 8.1.
CH
3
), 1.54e1.48 (m, 1 H, H-14ax), 1.38e1.31 (m, 3 H, H-7b, 2 H-
0
cyclopropyl), 1.28e1.23 (m, 1 H, H-4 b), 1.20e1.13 (m, 8 H, 2 H-
cyclopropyl, 5 -CH
0
3
, 4-CH
3
), 1.09e1.01 (m, 9 H, 2-CH
3
, 12-CH
), 0.80 (t, J ¼ 7.3 Hz, 3 H, 15-
: 175.9, 175.8, 171.7, 170.1, 166.4,
3
, 10-
CH
CH
3
), 0.87 (d, J ¼ 6.5 Hz, 3 H, 8-CH
3
13
3
). C NMR (CDCl
3
, 175 MHz)
d
4
.3.18.17. 3-O-Descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-(3-{[4-
154.0,149.2,147.7,139.9,136.7,135.7,130.2,127.2,124.2,122.4,121.0,
116.8, 111.8, 103.1, 87.6, 80.8, 79.6, 79.1, 78.3, 77.8, 74.5, 70.7, 69.3,
65.5, 61.7, 47.8, 44.1, 44.0, 43.4, 40.4, 36.7, 34.8, 29.7, 29.1, 27.3, 21.3,
21.2, 21.1, 19.6, 16.5, 16.1, 10.8, 9.3, 8.3, 8.0.
(
3-carbamoylpyrid-5-yl)but-3-yn-1-yl]amino}propanoyl)azi-
thromycin (26q). Compound 26q (48.0 mg, 0.0500 mmol, 12.8%)
was prepared starting from 3-O-descladinosyl-3-O-[2-(2-pyridyl)
acetyl]-6-O-acryloylazithromycin (0.300 g, 0.390 mmol) and com-
pound 11d (0.0790 g, 0.420 mmol) according to the general pro-
cedure (column chromatography eluents: CH
H
4.3.18.19. 3-O-Descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-(3-{[4-
(3-carbamoyl-1-ethyl-1,4-dihydro-4-oxoquinolin-6-yl)but-3-yn-1-yl]
amino}propanoyl)azithromycin (26s). Compound 26s (0.160 g,
0.150 mmol, 48.4%) was prepared starting from 3-O-descladinosyl-
2
Cl
2
/EtOH/NH
3
‧
ꢀ
2
O ¼ 10:0.4:0.05). Melting point: 104e107 C. HRMS (ESI)
þ
1
(
M þ H) m/z 953.5584, calcd for C50
CDCl , 400 MHz)
: 8.98 (d, J ¼ 2.1 Hz, 1 H, H-carbamoylpyridyl),
.70 (d, J ¼ 1.9 Hz, 1 H, H-carbamoylpyridyl), 8.59 (dd, J ¼ 5.0 Hz,
¼ 1.1 Hz, 1 H, H-pyridyl), 8.22 (t, J ¼ 2.1 Hz, 1 H, H-carba-
moylpyridyl), 7.67 (td, J ¼ 1.9 Hz,1 H, H-pyridyl), 7.35 (d,
¼7.7 Hz, J
J ¼ 7.8 Hz, 1 H, H-pyridyl), 7.21 (ddd, J ¼ 7.6 Hz, J ¼ 4.9 Hz,
¼ 1.1 Hz, 1 H, H-pyridyl), 7.00 (s, 1 H, -NH ), 6.45 (s, 1 H, -NH ),
.07 (dd, J
¼ 10.8 Hz,
77 6
H N O12 953.5594. H NMR
(
8
3
d
3-O-[2-(2-pyridyl)acetyl]-6-O-acryloylazithromycin
(0.300
g,
1
0.390 mmol) and compound 11f (0.0870 g, 0.310 mmol) according
J
2
to the general procedure (column chromatography eluents: CH
2
Cl
2
/
ꢀ
1
2
EtOH/NH
(ESI) (M þ H) m/z 1047.6026, calcd for C56
NMR (CDCl , 400 MHz)
: 9.68 (d, J ¼ 5.3 Hz, 1 H, -NH
H-quinolyl), 8.53e8.50 (m, 2 H, H-pyridyl, H-quinolyl), 7.73 (dd,
3
‧H
2
O ¼ 10:0.2:0.05). Melting point: 126e129 C. HRMS
þ
1
1
2
H
83
N
6
O
13 1047.6013. H
), 8.75 (s, 1 H,
J
3
2
2
3
d
2
5
1
¼ 10.6 Hz, J
2
¼ 1.9 Hz, 1 H, H-3), 4.76 (dd, J
1
J
2
¼ 2.0 Hz, 1 H, H-13), 4.37 (d, J ¼ 2.9 Hz, 1 H, H-5), 4.26 (d,
J
J
1
¼ 8.8 Hz, J
2
¼ 2.1 Hz, 1 H, H-quinolyl), 7.68 (td, J
1
¼ 7.7 Hz,
0
J ¼ 7.2 Hz, 1 H, H-1 ), 3.95 (q, J ¼ 16.0 Hz, 2 H, 3-O-CO-CH
2
-), 3.59 (s,
2
¼ 1.9 Hz, 1 H, H-pyridyl), 7.45e7.40 (m, 2 H, H-pyridyl, H-

26
B.-Z. Fan et al. / European Journal of Medicinal Chemistry 193 (2020) 112222
quinolyl), 7.20 (ddd, J
pyridyl), 5.89 (d, J ¼ 5.1 Hz,1 H, -NH
H, H-3), 4.80 (dd, J
1
¼ 7.6 Hz, J
2
¼ 4.9 Hz, J
3
1
¼ 1.1 Hz, 1 H, H-
¼10.6 Hz, J ¼ 2.0,
eluents: CH
2
Cl
2
/EtOH/NH
3
‧H
2
O ¼ 10:0.3:0.05). Melting point:
ꢀ
þ
2
), 5.11 (dd, J
2
127e130 C. HRMS (ESI) (M þ Na) m/z 1095.5991, calcd for
1
1
1
¼ 10.8 Hz, J
2
¼ 2.0, 1 H, H-13), 4.34 (d,
58 84 6 3
C H N NaO13 1095.5989. H NMR (CDCl , 400 MHz) d: 9.80 (d,
J ¼ 3.0 Hz, 1 H, H-5), 4.30 (q, J ¼ 7.3 Hz, 2 H, -CH
2
CH
3
), 4.25 (d,
J ¼ 5.1 Hz,1 H, -CO-NH-), 8.87 (s,1 H, H-quinolyl), 8.51 (d, J ¼ 4.8 Hz,
0
J ¼ 7.2 Hz, 1 H, H-1 ), 3.95 (dd, J
1
¼17.6 Hz, J
2
¼ 16.0 Hz, 2 H, 3-O-CO-
1 H, H-pyridyl), 8.48 (d, J ¼ 1.9 Hz, 1 H, H-quinolyl), 7.90 (d,
0
CH
2
-), 3.60 (s, 1 H, H-11), 3.49e3.39 (m, 2 H, H-5 , 12-OH), 3.23 (dd,
J ¼ 8.8 Hz, 1 H, H-quinolyl), 7.74 (dd, J
1
¼ 8.8 Hz, J ¼ 2.0 Hz, 1 H, H-
2
0
J
1
¼ 10.2 Hz, J
2
¼ 7.2 Hz, 1 H, H-2 ), 3.14e2.80 (m, 5 H, 6-O-CO-
quinolyl), 7.68 (td, J
1
¼ 7.7 Hz, J
2
¼ 1.9 Hz, 1 H, H-pyridyl), 7.41 (d,
¼ 7.5 Hz, J ¼ 4.9 Hz,
CH
CH
2
CH
2
eNHeCH
eNHeCH
2
CH
2
C≡CeAr, H-2), 2.71e2.57 (m, 7 H, 6-O-CO-
J ¼ 7.9 Hz, 1 H, H-pyridyl), 7.20 (ddd, J
1
2
0
2
CH
2
2
CH
2
C≡CeAr, H-10, H-3 ,11-OH), 2.44e2.39 (m,
J
3
¼ 1.1 Hz, 1 H, H-pyridyl), 5.11 (dd, J
1
¼10.6 Hz, J ¼ 1.9 Hz, 1 H, H-
2
1
H, H-9a), 2.37 (s, 3 H, -N-CH
3
), 2.30 (s, 6 H, -N(CH
3
)
2
), 2.28e2.25
3), 4.79 (dd, J
1
¼ 10.7 Hz, J
2
¼ 2.0 Hz, 1 H, H-13), 4.34 (d, J ¼ 3.0 Hz,
0
(
m, 1 H, H-4), 2.05e1.96 (m, 1 H, H-9b), 1.95e1.85 (m, 2 H, H-14eq,
1 H, H-5), 4.24 (d, J ¼ 7.2 Hz, 1 H, H-1 ), 3.94 (dd, J
1
¼ 18.0 Hz,
0
H-7a), 1.85e1.77 (m, 1 H, H-8), 1.68e1.63 (m, 1 H, H-4 a), 1.62 (s, 3 H,
J
2
¼ 15.4 Hz, 2 H, 3-O-CO-CH
2
-), 3.59 (s, 1 H, H-11), 3.53e3.40 (m,
0
6
-CH
3
), 1.53 (t, J ¼ 7.3 Hz, 3 H, -CH
2
CH
3
), 1.51e1.45 (m, 1 H, H-14ax),
3 H, 1 H-cyclopropyl, H-5 , 12-OH), 3.24 (dd, J
1 H, H-2 ), 3.14e3.06 (m, 1 H, 6-O-CO-CH
1
¼10.2 Hz, J
CH eNH-), 3.00 (d,
), 2.98e2.89 (m, H, 6-O-CO-
2
¼ 7.2 Hz,
0
1.35 (dd, J
1
¼ 14.0 Hz, J
2
¼ 6.3 Hz, 1 H, H-7b), 1.28e1.20 (m, 1 H, H-
2
2
0
0
4
b), 1.19e1.14 (m, 6 H, 5 -CH
3
, 4-CH
3
), 1.07 (s, 3 H, 12-CH
3
),
),
J
¼
4.9 Hz,
CH eNHeCH
(m, 7 H, 6-O-CO-CH
2.43e2.39 (m,1 H, H-9a), 2.37 (s, 3 H, NeCH
3
H, Ar-CH
3
3
1
0
1
1
.06e1.01 (m, 6 H, 10-CH
.80 (t, J ¼ 7.3 Hz, 3 H, 15-CH
75.7, 171.9, 170.0,166.6, 154.0,149.2,147.5, 137.9,136.6,135.8, 130.7,
28.0, 124.2, 122.3, 121.1, 115.8, 112.0, 103.2, 90.0, 87.3, 80.2, 79.5,
3
, 2-CH
3
), 0.87 (d, J ¼ 6.8 Hz, 3 H, 8-CH
3
CH
2
2
2
CH
2
C≡CeAr), 2.87e2.80 (m, 1 H, H-2), 2.71e2.56
1
3
0
3
). C NMR (CDCl
3
, 100 MHz)
d: 175.9,
2
CH
2
eNHeCH
2
CH
2
C≡CeAr, H-10, H-3 , 11-OH),
3
), 2.31 (s, 6 H, N(CH
3
)
2
),
2.30e2.28 (m,1 H, H-4), 2.05e1.96 (m,1 H, H-9b),1.94e1.85 (m, 2 H,
H-14eq, H-7a), 1.85e1.78 (m, 1 H, H-8), 1.69e1.63 (m, 1 H, H-4 a),
1.61 (s, 3 H, 6-CH
H-7b, 2 H-cyclopropyl), 1.28e1.20 (m, 1 H, H-4 b), 1.20e1.12 (m, 8 H,
0
7
4
8
8.9, 78.2, 77.8, 77.3, 74.5, 70.8, 69.4, 65.5, 61.7, 49.1, 48.1, 44.2, 44.0,
3.4, 38.6, 36.8, 35.2, 28.8, 27.4, 21.0, 20.3, 16.3, 16.0, 14.6, 10.8, 9.3,
.2.
3
), 1.56e1.48 (m, 1 H, H-14ax), 1.38e1.30 (m, 3 H,
0
0
2
H-cyclopropyl, 5 -CH
3
, 4-CH
3
), 1.09e1.01 (m, 9 H, 2-CH
), 0.80 (t, J ¼ 7.3 Hz, 3 H, 15-
: 176.1, 176.0, 172.0, 170.0, 165.4,
3 3
, 12-CH ,
4
.3.18.20. 3-O-Descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-(3-{[4-
10-CH
3
), 0.87 (d, J ¼ 6.9 Hz, 3 H, 8-CH
3
1
3
(
3-carbamoyl-1-methyl-1,4-dihydro-4-oxoquinolin-6-yl)but-3-yn-1-
yl]amino}propanoyl)azithromycin (26t). Compound 26t (84.0 mg,
.0810 mmol, 27.9%) was prepared starting from 3-O-descladino-
syl-3-O-[2-(2-pyridyl)acetyl]-6-O-acryloylazithromycin (0.270 g,
.350 mmol) and compound 11g (0.0790 g, 0.290 mmol) according
CH
3
). C NMR (CDCl
3
, 175 MHz)
d
154.0, 149.2, 147.0, 139.8, 136.6, 135.6, 130.2, 127.3, 124.2, 122.3,
121.0, 116.7, 112.2, 103.2, 89.7, 87.4, 80.4, 79.5, 79.0, 78.2, 77.9, 74.5,
70.7, 69.4, 65.5, 61.7, 48.1, 44.2, 44.0, 43.4, 40.4, 36.8, 34.7, 28.8, 27.4,
25.9, 21.2, 21.2, 20.2, 16.3, 16.1, 10.8, 9.3, 8.2, 8.2.
0
0
to the general procedure (column chromatography eluents: CH
2
Cl
2
/
ꢀ
EtOH/NH
ESI) (M þ H) m/z 1033.5845, calcd for C55
NMR (CDCl , 400 MHz)
: 9.63 (d, J ¼ 5.0 Hz, 1 H, -NH
H-quinolyl), 8.51 (d, J ¼ 3.9 Hz, 1 H, H-quinolyl), 8.46 (d, J ¼ 1.9 Hz,
H, H-pyridyl), 7.71 (dd, J ¼ 2.1 Hz, 1 H, H-quinolyl),
¼ 8.9 Hz, J
.70e7.65 (m, 1 H, H-pyridyl), 7.41 (d, J ¼ 7.9 Hz, 1 H, H-quinolyl),
3
‧H
2
O ¼ 10:0.5:0.05). Melting point: 139e142 C. HRMS
þ
1
(
H
81
N
6
O
13 1033.5856. H
), 8.69 (s, 1 H,
3
d
2
4.3.18.22. 3-O-Descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-(3-{[4-
(3-carboxy-1-cyclopropyl-1,4-dihydro-4-oxoquinolin-6-yl)but-3-yn-
1
1
2
1-yl]amino}propanoyl)azithromycin
(26w). Compound
26w
7
(25.5 mg, 0.0240 mmol, 9.23%) was prepared starting from 3-O-
descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-acryloylazithromycin
(0.200 g, 0.260 mmol) and compound 11j (0.0920 g, 0.310 mmol)
according to the general procedure (column chromatography elu-
7
.37 (d, J ¼ 8.8 Hz, 1 H, H-pyridyl), 7.20 (ddd, J
1
¼7.6 Hz, J
¼ 1.1 Hz, 1 H, H-pyridyl), 6.03 (d, J ¼ 5.1 Hz, 1 H, -NH
¼10.6 Hz, J ¼ 2.0 Hz, 1 H, H-3), 4.81 (dd, J ¼10.8 Hz, J
2
¼ 4.9 Hz,
J
J
3
2
), 5.11 (dd,
1
2
1
2
¼ 2.1 Hz,
0
1
3
H, H-13), 4.35 (d, J ¼ 3.0 Hz,1 H, H-5), 4.25 (d, J ¼ 7.2 Hz,1 H, H-1 ),
ents: CH
2
Cl
2
/MeOH/NH
3
‧H
2
O
¼
10:0.8:0.5). Melting point:
ꢀ
þ
.95 (dd, J
1
¼ 17.2 Hz, J
2
¼ 16.0 Hz, 2 H, 3-O-CO-CH
2
-), 3.90 (s, 3 H,
155e159 C. HRMS (ESI) (M þ H) m/z 1060.5836, calcd for
0
1
Ar-CH
3
), 3.61 (s, 1 H, H-11), 3.49e3.40 (m, 2 H, H-5 , 12-OH), 3.24
C H
57 82
N
5
O
14 1060.5853. H NMR (CDCl
H-quinolyl), 8.55e8.43 (m, 2 H, H-pyridyl, H-quinolyl), 8.01 (d,
J ¼ 8.9 Hz, 1 H, H-quinolyl), 7.85 (dd, J ¼ 8.8 Hz, J ¼ 2.0 Hz, 1 H, H-
quinolyl), 7.69 (td, J ¼ 1.9 Hz, 1 H, H-pyridyl), 7.42 (d,
¼ 7.7 Hz, J
J ¼ 7.7 Hz, 1 H, H-pyridyl), 7.21 (dd, J ¼ 7.7 Hz, J ¼ 4.9 Hz, 1 H, H-
pyridyl), 5.12 (dd, J
3
, 700 MHz) d: 8.85 (s, 1 H,
0
(
dd, J
1
¼ 10.2 Hz, J
2
¼ 7.2 Hz, 1 H, H-2 ), 3.14e2.88 (m, 5 H, 6-O-CO-
CH
2
CH eNHeCH
2
2
CH
2
C≡CeAr, 11-OH), 2.87e2.81 (m, 1 H, H-2),
1
2
2
3
.72e2.55 (m, 6 H, 6-O-CO-CH
), 2.43e2.38 (m, 1 H, H-9a), 2.37 (s, 3 H, -N-CH
2
CH
2
eNHeCH
2
CH
2
C≡CeAr, H-10, H-
), 2.30 (s, 6 H,
), 2.29e2.27 (m, 1 H, H-4), 2.05e1.97 (m, 1 H, H-9b),
.93e1.86 (m, 2 H, H-14eq, H-7a), 1.84e1.77 (m, 1 H, H-8), 1.68e1.63
1
2
0
3
1
2
-
N(CH
3
)
2
1
¼ 10.6 Hz, J ¼ 2.0 Hz, 1 H, H-3), 4.78 (d,
2
1
J ¼ 10.9 Hz, 1 H, H-13), 4.32 (s, 1 H, H-5), 4.25 (d, J ¼ 7.3 Hz, 1 H, H-
0
0
(
(
1
1
CH
1
1
7
m, 1 H, H-4 a), 1.62 (s, 3 H, 6-CH
dd, J
¼ 13.9 Hz, J
.19e1.14 (m, 6 H, 5 -CH
0-CH
), 0.87 (d, J ¼ 6.8 Hz, 3 H, 8-CH
3
), 1.56e1.47 (m, 1 H, H-14ax), 1.35
1 ), 3.99e3.89 (m, 2 H, 3-O-CO-CH
2
-), 3.60 (s, 1 H, H-11), 3.49e3.39
0
0
1
2
¼ 6.1 Hz, 1 H, H-7b), 1.25e1.20 (m, 1 H, H-4 b),
(m, 3 H, 1 H-cyclopropyl, H-5 , 12-OH), 3.24 (dd, J
1
¼ 10.2 Hz,
0
0
3
, 4-CH
3
), 1.09e1.01 (m, 9 H, 2-CH
), 0.80 (t, J ¼ 7.3 Hz, 3 H, 15-
: 175.9, 175.7, 171.9, 170.0, 166.6,
54.0, 149.2, 148.7, 138.9, 136.6, 135.8, 130.2, 127.5, 124.2, 122.3.
21.2, 116.0, 111.8, 103.2, 90.0, 87.3, 80.2, 79.5, 78.9, 78.2, 77.9, 77.3,
4.5, 70.7, 69.4, 65.5, 61.7, 48.0, 44.2, 44.0, 43.4, 41.4, 38.6, 36.8, 35.2,
3
, 12-CH
3
,
J
2
¼
7.1 Hz,
1
H, H-2 ), 2.98e2.79 (m,
5
H, 6-O-CO-
3
3
CH
CH
2
CH
2
eNHeCH
eNHeCH
2
CH
CH
2
C≡CeAr, 11-OH), 2.75e2.54 (m, 7 H, 6-O-CO-
C≡CeAr, H-2, H-10, H-3 ), 2.43e2.38 (m, 1 H,
), 2.30 (s, 6 H, -N(CH ), 2.27e2.28 (m,
13
0
3
). C NMR (CDCl
3
, 100 MHz)
d
2
CH
2
2
2
H-9a), 2.38 (s, 3 H, -N-CH
3
3 2
)
1 H, H-4), 2.04e1.98 (m, 1 H, H-9b), 1.93e1.87 (m, 2 H, H-14eq, H-
0
7a),1.86e1.80 (m,1 H, H-8),1.68e1.64 (m,1 H, H-4 a),1.63 (s, 3 H, 6-
2
8.7, 27.4, 21.2, 21.2, 21.0, 20.2, 16.4, 16.0, 10.8, 9.3, 8.1.
CH
3
), 1.56e1.50 (m, 1 H, H-14ax), 1.44e1.39 (m, 2 H, 2 H-cyclo-
0
propyl), 1.38e1.34 (m, 1 H, H-7b), 1.28e1.20 (m, 3 H, H-4 b, 2 H-
cyclopropyl),1.20e1.15 (m, 6 H, 5 -CH
0
4
.3.18.21. 3-O-Descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-(3-{[4-
3
, 4-CH
3
),1.09e1.02 (m, 9 H, 2-
), 0.82 (t,
: 178.1, 176.0,
(
3-methylcarbamoyl-1-cyclopropyl-1,4-dihydro-4-oxoquinolin-6-yl)
but-3-yn-1-yl]amino}propanoyl)azithromycin (26u). Compound
6u (20.6 mg, 0.0190 mmol, 9.05%) was prepared starting from 3-O-
descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-acryloylazithromycin
0.190 g, 0.250 mmol) and compound 11h (0.0640 g, 0.210 mmol)
according to the general procedure (column chromatography
CH
3
, 12-CH
3
, 10-CH
3
), 0.87 (d, J ¼ 6.9 Hz, 3 H, 8-CH
3
13
J ¼ 7.4 Hz, 3 H, 15-CH
3
). C NMR (CDCl
3
, 175 MHz)
d
2
172.0, 170.0, 166.8, 154.0, 149.2, 148.0, 140.0, 136.8, 136.6, 129.9,
125.9, 124.2, 122.6, 122.3, 117.2, 109.0, 103.2, 91.3, 87.3, 79.8, 79.5,
78.9, 78.1, 77.9, 74.5, 70.8, 69.5, 65.5, 61.8, 48.1, 44.2, 44.0, 43.4, 40.4,
36.8, 35.4, 35.4, 28.7, 27.5, 21.2, 20.4, 16.0, 10.9, 9.3, 8.3.
(

B.-Z. Fan et al. / European Journal of Medicinal Chemistry 193 (2020) 112222
27
0
0
4
1
.3.19. 2 -O-Acetyl-3-O-decladinosyl-6-acryloylazithromycin-
1,12-cyclic carbonate (27)
To a solution of compound 24 (0.500 g, 0.730 mmol) in 10 mL of
Cl , pyridine (0.700 mL, 8.69 mmol) was added dropwise to the
flask, and a solution of bis(trichloromethyl)carbonate (0.430 g,
.46 mmol) in 8 mL CH Cl was slowly added to the reaction
J
2
¼ 7.2 Hz, 1 H, H-2 ), 2.99e2.79 (m, 4 H, 6-O-CO-CH
2
CH
2
eNH-, H-
2
eNH-,
2, H-10), 2.77e2.66 (m, 7 H, 4 H-piperazinyl, 6-O-CO-CH
2
CH
), 2.19 (s, 3 H,
3
), 2.10e2.02 (m, 1 H, H-4), 1.99e1.86 (m, 3 H, H-9b, H-14eq,
0
H-3 ), 2.37e2.35 (m, 1 H, H-9a), 2.33 (s, 6 H, -N(CH
3
)
2
CH
2
2
-N-CH
H-7a), 1.85e1.78 (m, 1 H, H-8), 1.73e1.64 (m, 2 H, H-4 a, H-14ax),
1.60 (s, 3 H, 6-CH ), 1.48 (s, 3 H, 12-CH ), 1.42e1.36 (m, 2 H, 2 H-
cyclopropyl), 1.30e1.23 (m, 2 H, H-7b, H-4 b), 1.23e1.16 (m, 5 H, 5 -
CH ), 1.07 (d,
, 2 H-cyclopropyl), 1.12 (d, J ¼ 7.4 Hz, 3 H, 4-CH
J ¼ 6.6 Hz, 6 H, 10-CH , 2-CH ), 0.95e0.90 (m, 6 H, 8-CH , 15-CH ).
, 175 MHz) : 177.1, 177.1, 174.3, 171.8, 169.9, 167.1,
0
1
2
2
3
3
ꢀ
ꢀ
0
0
mixture. The mixture was stirred at ꢁ10 C ~ ꢁ5 C for 4 h, and then
at room temperature for 2 h. The reaction was quenched by the
addition of 20 mL of saturated NaCl and stirred slowly for 30 min.
3
3
3
3
3
3
1
3
The resulting mixture was diluted with CH
saturated NaHCO , water and brine. The organic layer was
concentrated and the residue was purified by flash silica gel column
chromatography (CH Cl /EtOH/NH ‧H
O ¼ 10:0.2:0.05) to obtain
2
Cl
2
, and washed with
C NMR (CDCl
3
d
3
154.4, 154.0, 153.5, 153.0, 149.2, 147.4, 146.0, 145.9, 139.1, 136.6,
124.3, 122.3, 119.7, 119.6, 112.4, 112.3, 108.1, 104.8, 104.8, 103.4, 86.7,
86.6, 85.2, 80.1, 77.9, 76.6, 70.6, 69.3, 65.7, 60.5, 53.4, 52.5, 49.8, 43.9,
43.4, 40.4, 38.0, 36.9, 35.3, 34.3, 32.8, 29.7, 29.1, 25.8, 21.8, 21.4, 21.2,
21.0, 15.5, 15.2, 10.2, 9.5, 8.2, 7.1.
2
2
3
2
pure compound 27 (0.390 g, 0.550 mmol, 75.3%). HRMS (ESI)
þ
1
(
(
M þ H) m/z 713.4227, calcd for C36
H
61
N
2
O
12 713.4219. H NMR
¼ 1.6 Hz, 1 H, 6-O-CO-
),
), 4.92 (dd,
CDCl
3
, 400 MHz)
d
: 6.34 (dd, J
1
¼ 17.3 Hz, J
2
CH¼CH
2
), 6.04 (dd, J
.78 (dd, J
1
¼17.2 Hz, J
2
¼ 10.3 Hz, 1 H, 6-O-CO-CH¼CH
2
4.3.21.2. 3-O-Descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-(3-{2-[(3-
carbamoyl-6-fluoro-1-cyclopropyl-1,4-dihydro-4-oxoquinolin-7-yl)
piperazin-1-yl]}propanoyl)azithromycin-11,12-cyclic
(29k). Compound 29k (56.9 mg, 0.0510 mmol, 20.4%) was prepared
starting from 3-O-descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-
acryloylazithromycin-11,12-cyclic carbonate (0.200 g, 0.250 mmol)
and compound 20 (0.0780 g, 0.250 mmol) according to the general
procedure (column chromatography eluents: CH
O ¼ 10:0.3:0.05). Melting point: 145e148 C. HRMS (ESI)
5
1
¼ 10.3 Hz, J ¼ 1.6 Hz, 1 H, 6-O-CO-CH¼CH
2
2
J
1
¼ 9.2 Hz, J
2
¼ 3.3 Hz, 1 H, H-13), 4.80 (dd, J
1
¼10.4 Hz, J
2
¼ 7.6 Hz,
carbonate
0
0
1
4
H, H-2 ), 4.70 (d, J ¼ 2.6 Hz, 1 H, H-5), 4.62 (d, J ¼ 7.6 Hz, 1 H, H-1 ),
0
.51 (d, J ¼ 3.8 Hz, 1 H, H-11), 3.54e3.42 (m, 2 H, H-5 , H-3), 2.84
0
(
dq, J
1
¼ 6.5 Hz, J
2
¼ 3.7 Hz, 1 H, H-10), 2.77e2.68 (m, 1 H, H-3 ),
2
.68e2.61 (m, 1 H, H-2), 2.34e2.29 (m, 1 H, H-9a), 2.27 (s, 6 H,
0
-
N(CH
3
)
2
), 2.22 (s, 3 H, -N-CH
3
), 2.07 (s, 3 H, 2 -O-CO-CH
3
),
2
Cl
2
/EtOH/NH
3
‧
ꢀ
2
(
1
7
.03e1.97 (m,1 H, H-9b),1.97e1.88 (m, 2 H, H-4, H-14eq),1.88e1.82
m, 1 H, H-7a), 1.77e1.68 (m, 2 H, H-4 a, H-8), 1.68e1.63 (m, 1 H, H-
4ax), 1.61 (s, 3 H, 6-CH
b),1.27e1.23 (m, 6 H, 5 -CH
d, J ¼ 6.5 Hz, 3 H, 10-CH ), 0.93e0.87 (m, 9 H, 15-CH
CH ).
H
2
0
þ
1
(M þ H) m/z 1120.5948, calcd for C58
(CDCl , 400 MHz)
: 9.72 (d, J ¼ 5.4 Hz, 1 H, -NH
quinolyl), 8.51 (ddd, J ¼ 1.9 Hz, J ¼ 0.9 Hz, 1 H, H-
¼ 4.9 Hz, J
pyridyl), 8.03 (d, J ¼ 13.3 Hz, 1 H, H-quinolyl), 7.67 (td, J ¼ 7.7 Hz,
¼ 1.8 Hz, 1 H, H-pyridyl), 7.39 (dt, J ¼ 7.8 Hz, J ¼ 1.1 Hz, 1 H, H-
pyridyl), 7.32 (d, J ¼ 7.1 Hz, 1 H, H-quinolyl), 7.21 (ddd, J ¼ 7.6 Hz,
¼ 4.9 Hz, J ¼ 1.1 Hz, 1 H, H-pyridyl), 5.71 (d, J ¼ 5.3 Hz, 1 H, -NH ),
H83FN
7
O14 1120.5977. H NMR
3
0
), 1.44 (s, 3 H, 12-CH
3
), 1.40e1.29 (m, 1 H, H-
3
d
2
), 8.81 (s, 1 H, H-
0
3
, 2-CH
3
),1.23e1.16 (m,1 H, H-4 b),1.06
1
2
3
(
3
3
, 8-CH
3
, 4-
1
3
J
2
1
2
1
0
4
.3.20. 2 -O-Acetyl-3-O-descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-
J
2
3
2
O-acryloylazithromycin-11,12-cyclic carbonate (28)
5.11 (d, J ¼ 10.4 Hz,1 H, H-3), 4.88 (dd, J
1
¼8.2 Hz, J ¼ 3.8 Hz,1 H, H-
2
Compound 28 (0.970 g, 1.16 mmol, 84.7%) was prepared starting
from compound 27 (0.980 g, 1.37 mmol) and 2-pyridylacetic acid
hydrochloride (0.480 g, 2.74 mmol) according to the procedure
used to prepare compound 25 (column chromatography eluents:
13), 4.58 (d, J ¼ 3.0 Hz, 1 H, H-5), 4.44 (d, J ¼ 5.7 Hz, 1 H, H-11), 4.17
0
(d, J ¼ 7.3 Hz, 1 H, H-1 ), 3.93 (dd, J
1
¼ 20.0 Hz, J ¼ 16.0 Hz, 2 H, 3-O-
2
CO-CH
2
-), 3.50e3.44 (m, 1 H, 1 H-cyclopropyl), 3.43e3.36 (m, 1 H,
0
0
H-5 ), 3.34e3.28 (m, 4 H, 4 H-piperazinyl), 3.28e3.22 (m, 1 H, H-2 ),
CH
2
Cl
2
/EtOH/NH
3
‧H
2
O ¼ 10:0.1:0.05).
2.90e2.80 (m, 4 H, 6-O-CO-CH
2
CH
2
eNH-, H-2, H-10), 2.78e2.66
CH eNH-), 2.53e2.43 (m, 1 H,
0
3 2
H-3 ), 2.35 (s, 6 H, -N(CH ) ), 2.34e2.32 (m, 1 H, H-9a), 2.18 (s, 3 H,
(m, 6 H, 4 H-piperazinyl, 6-O-CO-CH
2
2
4.3.21. General procedure for the synthesis of compounds 29j, 29k,
2
9r and 29w
-N-CH
3
), 2.10e2.02 (m, 1 H, H-9b), 1.99e1.87 (m, 3 H, H-4, H-14eq,
0
The compound 29 series was prepared starting from compound
8 and the corresponding amines according to the procedure used
H-7a), 1.86e1.78 (m, 1 H, H-8), 1.74e1.64 (m, 2 H, H-4 a, H-14ax),
1.59 (s, 3 H, 6-CH
2
3
), 1.48 (s, 3 H, 12-CH
3
), 1.37e1.30 (m, 2 H, 2 H-
0
to prepare the compound 26 series.
cyclopropyl), 1.30e1.22 (m, 2 H, H-7b, H-4 b), 1.18 (d, J ¼ 6.2 Hz, 3 H,
0
5
-CH
3
), 1.17e1.14 (m, 2 H, 2 H-cyclopropyl), 1.11 (d, J ¼ 7.4 Hz, 3 H,
4.3.21.1. 3-O-Descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-(3-{2-[(3-
2-CH
3
), 1.09e1.05 (m, 6 H, 10-CH
3
, 4-CH
, 100 MHz) d
3
), 0.95e0.90 (m, 6 H, 8-
: 175.4, 174.2, 171.9,
13
carboxy-6-fluoro-1-cyclopropyl-1,4-dihydro-4-oxoquinolin-7-yl)
piperazin-1-yl]}propanoyl)azithromycin-11,12-cyclic carbonate (29j).
Compound 29j (20.0 mg, 0.0180 mmol, 13.8%) was prepared start-
ing from 3-O-descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-acryl-
oylazithromycin-11,12-cyclic carbonate (0.100 g, 0.130 mmol) and
ciprofloxacin (0.0560 g, 0.170 mmol) according to the general
CH , 15-CH
3
3
). C NMR (CDCl
3
169.9, 166.8, 154.7, 154.0, 153.5, 152.2, 149.2, 147.2, 145.1, 145.0,
138.6, 136.6, 124.3, 122.3, 121.8, 112.8, 112.6, 111.0, 104.8, 103.4, 86.7,
86.7, 85.0, 80.0, 78.0, 77.2, 76.6, 70.6, 69.4, 65.6, 60.4, 53.4, 52.6,
49.9, 43.9, 43.5, 40.4, 38.0, 37.0, 34.7, 34.4, 32.8, 25.8, 21.8, 21.5, 21.2,
21.0, 15.5, 15.4, 10.1, 9.5, 8.2, 7.2.
procedure (column chromatography eluents: CH
2
Cl
2
/MeOH/NH
3
‧
ꢀ
þ
H
2
O ¼ 10:0.8:0.5). Melting point: 148e158 C. HRMS (ESI) (M þ H)
4.3.21.3. 3-O-Descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-(3-{[4-(3-
carbamoyl-1-cyclopropyl-1,4-dihydro-4-oxoquinolin-6-yl)but-3-yn-
1-yl]amino}propanoyl)azithromycin-11,12-cyclic carbonate (29r).
Compound 29r (19.8 mg, 0.0180 mmol, 8.18%) was prepared
starting from 3-O-descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-
acryloylazithromycin-11,12-cyclic carbonate (0.300 g, 0.380 mmol)
and compound 11e (0.0640 g, 0.220 mmol) according to the general
1
m/z 1121.5839, calcd for C58
H82FN
6
O
15 1121.5817. H NMR (CDCl
: 15.05 (s, 1 H, -COOH), 8.76 (s, 1 H, H-quinolyl),
.52e8.49 (m, 1 H, H-pyridyl), 8.00 (d, J ¼ 13.1 Hz, 1 H, H-quinolyl),
¼ 7.7 Hz, J ¼ 1.9 Hz, 1 H, H-pyridyl), 7.38 (d, J ¼ 8.0 Hz,
H, H-pyridyl), 7.36 (d, J ¼ 7.3 Hz, 1 H, H-quinolyl), 7.20 (ddd,
¼ 7.5 Hz, J ¼ 4.9 Hz, J ¼ 1.1 Hz, 1 H, H-pyridyl), 5.10 (d,
J ¼ 10.8 Hz, 1 H, H-3), 4.88 (dd, J ¼ 8.3 Hz, J ¼ 3.8 Hz, 1 H, H-13),
3
,
4
8
00 MHz) d
7.67 (td, J
1
2
1
J
1
2
3
1
2
procedure (column chromatography eluents: CH
2
Cl
2
/EtOH/NH
3
‧
ꢀ
4
.55 (d, J ¼ 3.1 Hz, 1 H, H-5), 4.46 (d, J ¼ 5.4 Hz, 1 H, H-11), 4.19 (d,
H
2
O ¼ 10:0.3:0.05). Melting point: 143e146 C. HRMS (ESI)
0
þ
1
J ¼ 7.2 Hz,1 H, H-1 ), 3.93 (dd, J
1
¼19.6 Hz, J
2
¼ 16.0 Hz, 2 H, 3-O-CO-
(M þ H) m/z 1085.5815, calcd for C58
(CDCl , 400 MHz)
: 9.63 (d, J ¼ 5.2 Hz, 1 H, -NH
quinolyl), 8.51 (ddd, J ¼ 1.9 Hz, J ¼ 0.9 Hz, 1 H, H-
¼ 4.9 Hz, J
H
81
N
6
O
14 1085.5805. H NMR
0
CH
2
-), 3.58e3.51 (s, 1 H, 1 H-cyclopropyl), 3.45e3.38 (m, 1 H, H-5 ),
3
d
2
), 8.86 (s, 1 H, H-
3
.35 (t, J ¼ 5.0 Hz, 4 H, 4 H-piperazinyl), 3.24 (dd, J
1
¼ 10.1 Hz,
1
2
3

28
B.-Z. Fan et al. / European Journal of Medicinal Chemistry 193 (2020) 112222
þ
quinolyl), 8.47 (d, J ¼ 2.0 Hz, 1 H, H-pyridyl), 7.91 (d, J ¼ 8.8 Hz, 1 H,
H-quinolyl), 7.74 (dd, J ¼ 2.0 Hz, 1 H, H-quinolyl), 7.68
¼ 8.8 Hz, J
td, J ¼ 1.8 Hz, 1 H, H-pyridyl), 7.39 (d, J ¼ 8.0 Hz, 1 H, H-
¼7.7 Hz, J
pyridyl), 7.20 (ddd, J ¼ 4.9 Hz, J ¼ 1.2 Hz, 1 H, H-pyr-
¼ 7.6 Hz, J
CH
832.4581, calcd for
400 MHz)
: 8.58 (d, J ¼ 2.3 Hz, 1 H, H-pyridyl), 8.56 (dd, J
¼ 1.7 Hz, 1 H, H-pyridyl), 7.77 (td, J ¼ 7.9 Hz, J ¼ 2.0 Hz, 1 H, H-
pyridyl), 7.30 (ddd, J ¼ 4.8 Hz, J ¼ 0.8 Hz, 1 H, H-
¼ 7.9 Hz, J
pyridyl), 6.39 (dd, J ¼ 1.6 Hz, 1 H, 6-O-CO-CH¼CH ),
¼ 17.3 Hz, J
6.09 (dd, J ¼ 10.3 Hz, 1 H, 6-O-CO-CH¼CH ), 5.75 (dd,
¼ 17.2 Hz, J
¼10.3 Hz, J ¼ 1.7 Hz,1 H, 6-O-CO-CH¼CH ), 5.06 (dd, J ¼10.6 Hz,
¼ 1.4 Hz, 1 H, H-3), 4.87 (dd, J
2
Cl
2
/EtOH/NH
3
‧H
2
O ¼ 10:0.1:0.05). HRMS (ESI) (M þ H) m/z
1
1
2
C
H
43 66
N
3
O
13 832.4590.
H
NMR (CDCl
3
,
(
1
2
d
1
¼ 4.8 Hz,
1
2
3
J
2
1
2
idyl), 5.78 (d, J ¼ 5.1 Hz, 1 H, -NH
2
), 5.07 (d, J ¼ 10.4 Hz, 1 H, H-3),
1
2
3
4
5
.84 (dd, J
1
¼7.5 Hz, J
2
¼ 4.3 Hz,1 H, H-13), 4.60 (d, J ¼ 3.2 Hz,1 H, H-
1
2
2
0
), 4.40 (d, J ¼ 2.5 Hz, 1 H, H-11), 4.17 (d, J ¼ 7.3 Hz, 1 H, H-1 ), 3.93
1
2
2
(
dd, J
1
¼ 20.0 Hz, J
2
¼ 15.6 Hz, 2 H, 3-O-CO-CH
2
-), 3.60e3.54 (m, 1 H,
J
J
1
2
2
1
0
0
2
5
6
5
1
-OH), 3.54e3.48 (m, 1 H, 1 H-cyclopropyl), 3.43e3.34 (m, 1 H, H-
2
1
¼ 8.1 Hz, J
2
¼ 4.0 Hz, 1 H, H-13),
0
0
), 3.22 (dd, J
1
¼ 10.2 Hz, J
2
¼ 7.2 Hz, 2 H, H-2 ), 3.08e2.91 (m, 6 H,
4.75 (dd, J
1
¼10.5 Hz, J
2
¼ 7.4 Hz, 1 H, H-2 ), 4.58 (d, J ¼ 3.0 Hz, 1 H,
0
-O-CO-CH
H, H-3 , 6-O-CO-CH
2
CH
2
eNHeCH
2
CH
eNHeCH
), 2.15 (s, 3 H, -N-CH
2
C≡CeAr, H-2, H-10), 2.79e2.61 (m,
CH C≡CeAr), 2.37e2.33 (m,
), 2.06e2.00
H-5), 4.44 (d, J ¼ 5.4 Hz, 1 H, H-11), 4.08 (d, J ¼ 7.5 Hz,1 H, H-1 ),
0
0
2
CH
2
2
2
3.78e3.68 (m, 2 H, 3-O-CO-CH
2
-), 3.19e3.10 (m, 1 H, H-5 ),
0
H, H-9a), 2.32 (s, 6 H, -N(CH
3
)
2
3
2.89e2.87 (m, 2 H, H-3 , H-2), 2.63e2.53 (m, 1 H, H-10), 2.35e2.30
(
1
(
2
(
0
1
m, 1 H, H-9b), 1.97e1.87 (m, 3 H, H-4, H-14eq, H-7a), 1.83e1.74 (m,
(m, 1 H, H-9a), 2.27 (s, 6 H, -N(CH
3
)
2
), 2.17 (s, 3 H, -N-CH
3
), 2.11 (s,
0
0
H, H-8), 1.72e1.63 (m, 2 H, H-4 a, H-14ax), 1.58 (s, 3 H, 6-CH
3
), 1.48
3 H, 2 -O-CO-CH
3
), 2.09e2.05 (m,1 H, H-4), 2.01e1.90 (m, 2 H, H-9b,
0
s, 3 H, 12-CH
3
), 1.38e1.32 (m, 2 H, 2 H-cyclopropyl), 1.27e1.19 (m,
H-14eq), 1.86e1.76 (m, 2 H, H-7a, H-8), 1.70e1.62 (m, 2 H, H-4 a, H-
0
0
H, H-7b, H-4 b), 1.19e1.15 (m, 5 H, 2 H-cyclopropyl, 5 -CH
3
), 1.10
, 10-CH ),
, 100 MHz)
14ax), 1.58 (s, 3 H, 6-CH
3
), 1.46 (s, 3 H, 12-CH
3
), 1.34e1.26 (m, 1 H, H-
0
0
d, J ¼ 7.4 Hz, 3 H, 4-CH
3
), 1.08e1.03 (m, 6 H, 2-CH
3
3
4 b),1.26e1.22 (m, 1 H, H-7b),1.18 (d, J ¼ 6.1 Hz, 3 H, 5 -CH
3
), 1.07 (d,
, 4-CH ),
13
.94e0.85 (m, 6 H, 8-CH
3
, 15-CH
3
). C NMR (CDCl
3
d:
J ¼ 6.5 Hz, 3 H, 10-CH
3
), 0.98e0.94 (m, 6 H, 2-CH
).
3
3
75.9, 174.2, 172.4, 170.0, 166.4, 154.0, 153.4, 149.2, 147.7, 139.9,
0.93e0.87 (m, 6 H, 8-CH , 15-CH
3
3
136.6, 135.7, 130.2, 127.3, 124.3, 122.3, 121.2, 116.8, 111.8, 103.5, 89.7,
8
4
6.9, 86.8, 84.2, 80.4, 79.8, 78.0, 77.2, 70.6, 69.4, 66.4, 65.6, 60.2,
8.1, 44.7, 43.9, 43.4, 40.3, 37.7, 36.9, 34.9, 34.8, 34.0, 28.8, 25.4, 21.8,
4.3.23. General procedure for the synthesis of compounds 31r and
31w
2
1.6, 21.2, 21.0, 20.4, 15.8, 15.3, 10.0, 9.5, 8.3, 7.4.
The compounds 31r and 31w were prepared starting from
compound 30 and corresponding amines according to the pro-
cedure used to prepare the compound 26 series.
4.3.21.4. 3-O-Descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-(3-{[4-(3-
carboxy-1-cyclopropyl-1,4-dihydro-4-oxoquinolin-6-yl)but-3-yn-1-
yl]amino}propanoyl)azithromycin-11,12-cyclic carbonate (29w).
Compound 29w (22.7 mg, 0.0210 mmol, 8.75%) was prepared
starting from 3-O-descladinosyl-3-O-[2-(2-pyridyl)acetyl]-6-O-
acryloylazithromycin-11,12-cyclic carbonate (0.190 g, 0.240 mmol)
and compound 11j (0.0960 g, 0.320 mmol) according to the general
4.3.23.1. 3-O-Descladinosyl-3-O-[2-(3-pyridyl)acetyl]-6-O-(3-{[4-(3-
carbamoyl-1-cyclopropyl-1,4-dihydro-4-oxoquinolin-6-yl)but-3-yn-
1-yl]amino}propanoyl)azithromycin-11,12-cyclic carbonate (31r).
Compound 31r (0.110 g, 0.100 mmol, 33.3%) was prepared starting
from 3-O-descladinosyl-3-O-[2-(3-pyridyl)acetyl]-6-O-acryloylazi-
thromycin-11,12-cyclic carbonate (0.300 g, 0.380 mmol) and com-
pound 11e (0.0890 g, 0.300 mmol) according to the general
procedure (column chromatography eluents: CH
2
Cl
2
/MeOH/NH
3
‧
ꢀ
þ
H
2
O ¼ 10:0.8:0.5). Melting point: 167e170 C. HRMS (ESI) (M þ H)
1
m/z 1086.5669, calcd for C58
00 MHz) : 8.85 (s, 1 H, H-quinolyl), 8.53e8.44 (m, 2 H, H-pyridyl,
¼8.8 Hz,
¼ 2.0 Hz, 1 H, H-quinolyl), 7.66 (d, J ¼ 8.5 Hz, 1 H, H-pyridyl), 7.39
d, J ¼ 7.9 Hz, 1 H, H-pyridyl), 7.19 (d, J ¼ 7.0 Hz, 1 H, H-pyridyl), 5.08
d, J ¼ 10.6 Hz, 1 H, H-3), 4.84 (dd, J ¼7.9 Hz, J ¼ 4.3 Hz, 1 H, H-13),
H
80
N
5
O15 1086.5645. H NMR (CDCl
3
,
procedure (column chromatography eluents: CH
2
Cl
2
/EtOH/NH
3
‧
ꢀ
4
d
H
2
O ¼ 10:0.3:0.05). Melting point: 133e136 C. HRMS (ESI)
þ
1
H-quinolyl), 8.01 (d, J ¼ 8.8 Hz,1 H, H-quinolyl), 7.83 (dd, J
1
(M þ H) m/z 1085.5814, calcd for C58
(CDCl , 400 MHz)
: 9.63 (d, J ¼ 5.2 Hz, 1 H, -NH
quinolyl), 8.55 (d, J ¼ 2.3 Hz, 1 H, H-pyridyl), 8.53 (dd, J
¼ 1.7 Hz, H-pyridyl), 8.48 (d, J ¼ 1.9 Hz, 1 H, H-quinolyl), 7.91 (d,
J ¼ 8.8 Hz, 1 H, H-quinolyl), 7.78e7.72 (m, 2 H, H-quinolyl, H-pyr-
idyl), 7.31e7.26 (m, 1 H, H-pyridyl), 5.78 (d, J ¼ 5.2 Hz, 1 H, -NH ),
H
81
N
6
O
14 1085.5805. H NMR
), 8.87 (s, 1 H, H-
¼ 4.8 Hz,
J
2
3
d
2
(
(
1
1
2
J
2
4
.58 (d, J ¼ 3.2 Hz, 1 H, H-5), 4.41 (d, J ¼ 6.1 Hz, 1 H, H-11), 4.17 (d,
0
J ¼ 7.3 Hz, 1 H, H-1 ), 3.96e3.87 (m, 2 H, 3-O-CO-CH
2
-), 3.64e3.48
2
0
(
m, 2 H, 1 H-cyclopropyl, 12-OH), 3.43e3.34 (m, 1 H, H-5 ),
5.08 (d, J ¼ 10.8 Hz,1 H, H-3), 4.84 (dd, J
1
¼7.5 Hz, J ¼ 4.2 Hz,1 H, H-
2
0
3
.24e3.16 (m,
CH eNHeCH
H, 6-O-CO-CH
H, H-9a), 2.29 (s, 6 H, -N(CH
1
H, H-2 ), 3.02e2.78 (m,
CH C≡CeAr, H-2, H-10, 11-OH), 2.76e2.41 (m,
CH
7
H, 6-O-CO-
13), 4.62 (d, J ¼ 3.2 Hz, 1 H, H-5), 4.38 (d, J ¼ 6.7 Hz, 1 H, H-11), 4.03
0
CH
5
1
2
2
2
2
(d, J ¼ 7.2 Hz, 1 H, H-1 ), 3.72 (dd, J
1
¼ 20.0 Hz, J ¼ 9.6 Hz, 2 H, 3-O-
2
0
2
2
eNHeCH
2
CH
2
C≡CeAr, H-3 ), 2.36e2.31 (m,
), 2.06e2.00
CO-CH
2
-), 3.54e3.48 (m, 1 H, 1 H-cyclopropyl), 3.43e3.35 (m, 1 H,
0
0
0
3
)
2
), 2.15 (s, 3 H, -N-CH
3
2 -OH), 3.25e3.16 (m, 2 H, H-5 , H-2 ), 3.05e2.64 (m, 10 H, 6-O-CO-
0
(
1
m, 1 H, H-4), 1.96e1.85 (m, 3 H, H-9b, H-14eq, H-7a), 1.82e1.74 (m,
CH
2.37e2.33 (m, 1 H, H-9a), 2.28 (s, 6 H, -N(CH
CH ), 2.06e2.00 (m, 1 H, H-4), 1.96e1.88 (m, 3 H, H-9b, H-14eq, H-
2
CH
2
eNHeCH
2
CH
2
C≡CeAr, H-2, H-10), 2.54e2.45 (m,1 H, H-3 ),
0
H, H-8), 1.70e1.61 (m, 1 H, H-4 a), 1.59 (s, 3 H, 6-CH
3
), 1.57e1.54
3 2
) ), 2.15 (s, 3 H, -N-
(
m, 1 H, H-14ax), 1.47 (s, 3 H, 12-CH
3
), 1.45e1.38 (m, 2 H, 2 H-
3
0
cyclopropyl), 1.28e1.19 (m, 4 H, H-7b, H-4 b, 2 H-cyclopropyl), 1.17
7a), 1.83e1.75 (m, 1 H, H-8), 1.72e1.65 (m, 1 H, H-14ax), 1.62e1.58
0
0
(
(
(
d, J ¼ 6.1 Hz, 3 H, 5 -CH
3
), 1.11 (d, J ¼ 7.3 Hz, 3 H, 4-CH
), 0.93e0.85 (m, 6 H, 8-CH ,15-CH
: 178.1, 174.2, 172.4, 169.9, 166.8, 153.4, 149.2,
48.1, 140.0, 136.8, 136.6, 129.9, 125.9, 124.3, 122.6, 122.2, 117.3,
09.0, 103.6, 86.8, 86.7, 79.8, 78.0, 77.2, 70.6, 69.5, 65.6, 60.3, 48.2,
4.7, 43.9, 43.4, 40.3, 37.8, 36.9, 35.4, 35.2, 34.1, 25.5, 21.7, 21.5, 21.2,
1.0, 20.7, 15.6, 15.4, 10.0, 9.6, 8.3, 7.3.
3
), 1.09e1.00
(m, 1 H, H-4 a), 1.57 (s, 3 H, 6-CH
3
), 1.49 (s, 3 H, 12-CH
3
), 1.38e1.32
1
3
0
m, 6 H, 2-CH
3
,10-CH
3
3
3
). C NMR
(m, 2 H, 2 H-cyclopropyl), 1.24e1.17 (m, 4 H, H-7b, H-4 b, 2 H-
0
CDCl , 100 MHz)
3
d
cyclopropyl), 1.16 (d, J ¼ 6.1 Hz, 3 H, 5 -CH
3
), 1.13 (d, J ¼ 7.4 Hz, 3 H,
), 0.91
3
). C NMR (CDCl ,
1
1
4
2
4-CH
(d, J ¼ 6.6 Hz, 8-CH
100 MHz)
3
), 1.06 (d, J ¼ 6.4 Hz, 10-CH
3
), 0.97 (d, J ¼ 6.8 Hz, 2-CH
3
13
3
), 0.88 (d, J ¼ 7.4 Hz, 15-CH
3
d: 175.9, 174.0, 172.5, 169.9, 166.4, 153.4, 150.4, 148.8,
147.7, 139.9, 137.1, 135.6, 130.3, 129.5, 127.3, 123.5, 121.2, 116.8, 111.9,
03.7, 89.9, 87.0, 86.7, 84.1, 80.3, 80.1, 78.3, 77.2, 70.4, 69.6, 66.4,
1
0
4
.3.22. 2 -O-Acetyl-3-O-descladinosyl-3-O-[2-(3-pyridyl)acetyl]-6-
66.0, 60.2, 48.2, 44.7, 43.5, 40.3, 38.5, 37.7, 36.9, 35.2, 34.8, 34.0,
28.3, 25.5, 21.8, 21.6, 21.2, 21.0, 20.6, 15.8, 15.2, 10.0, 9.6, 8.3, 7.5.
O-acryloylazithromycin-11,12-cyclic carbonate (30)
Compound 30 (0.960 g, 1.15 mmol, 54.8%) was prepared starting
from compound 27 (1.50 g, 2.10 mmol) and 3-pyridylacetic acid
hydrochloride (0.730 g, 4.20 mmol) according to the procedure
used to prepare compound 25 (column chromatography eluents:
4.3.23.2. 3-O-Descladinosyl-3-O-[2-(3-pyridyl)acetyl]-6-O-(3-{[4-
(3-carboxy-1-cyclopropyl-1,4-dihydro-4-oxoquinolin-6-yl)but-3-yn-
1-yl]amino}propanoyl)azithromycin-11,12-cyclic carbonate (31w).

B.-Z. Fan et al. / European Journal of Medicinal Chemistry 193 (2020) 112222
29
Compound 31w (23.9 mg, 0.0220 mmol, 8.80%) was prepared
starting from 3-O-descladinosyl-3-O-[2-(3-pyridyl)acetyl]-6-O-
acryloylazithromycin-11,12-cyclic carbonate (0.190 g, 0.240 mmol)
and compound 11j (0.0890 g, 0.300 mmol) according to the general
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967e2983.
2
[6] N.E. Allen, Macrolide resistance in Staphylococcus aureus: inducers of mac-
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procedure (column chromatography eluents: CH
2
Cl
2
/MeOH/NH
3
‧
ꢀ
þ
H
2
O ¼ 10:0.8:0.5). Melting point: 127e130 C. HRMS (ESI) (M þ H)
[
8] J.-H. Liang, X. Han, Structure-activity relationships and mechanism of action of
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1
m/z 1086.5656, calcd for C58
00 MHz)
: 8.84 (s, 1 H, H-quinolyl), 8.55 (d, J ¼ 2.3 Hz, 1 H, H-
pyridyl), 8.53 (dd, J ¼ 1.6 Hz, H-pyridyl), 8.49 (d,
¼ 4.8 Hz, J
J ¼ 1.9 Hz, 1 H, H-quinolyl), 8.01 (d, J ¼ 8.8 Hz, 1 H, H-quinolyl), 7.82
dd, J ¼ 2.0 Hz, 1 H, H-quinolyl), 7.75 (td, J ¼ 7.9 Hz,
¼ 8.8 Hz, J
¼ 2.0 Hz, 1 H, H-pyridyl), 7.31e7.26 (m, 1 H, H-pyridyl), 5.08 (d,
J ¼ 10.4 Hz, 1 H, H-3), 4.84 (dd, J ¼ 7.7 Hz, J ¼ 4.2 Hz, 1 H, H-13),
80 5 3
H N O15 1086.5645. H NMR (CDCl ,
4
d
[
9] H.C. Paljetak, L. Tomaskovic, M. Matijasic, M. Bukvic, A. Fajdetic, D. Verbanac,
M. Peric, Macrolide hybrid compounds: drug discovery opportunities in
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2
919e940.
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1
2
1
[
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V. Stimac, H. Cipcic, M.D. Kramaric, V. Erakovic, A. Hasenohrl, N. Marsic,
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O. Le Martret, V. Loyau, N. Tessot, Synthesis and antibacterial activity of
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12] T. Tanikawa, T. Asaka, M. Kashimura, Y. Misawa, K. Suzuki, M. Sato, K. Kameo,
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13] J.A. Dunkle, L. Xiong, A.S. Mankin, J.H.D. Cate, Structures of the Escherichia coli
ribosome with antibiotics bound near the peptidyl transferase center explain
spectra of drug action, Proc. Natl. Acad. Sci. 107 (2010) 17152e17157.
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15] A. Fajdetic, H.C. Paljetak, G. Lazarevski, A. Hutinec, S. Alihodzic, M. Derek,
V. Stimac, D. Andreotti, V. Sunjic, J.M. Berge, S. Mutak, M. Dumic, S. Lociuro,
D.J. Holmes, N. Marsic, V.E. Haber, R. Spaventi, 4 ’’-O-(omega-Quinolylamino-
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16] I.P. Jakopovic, G. Kragol, A.K. Forrest, C.S.V. Frydrych, V. Stimac, S. Kapic,
M.M. Skugor, M. Ilijas, H.C. Paljetak, D. Jelic, D.J. Holmes, D.M.B. Hickey,
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characterized by two ether bonds in the linker, Bioorg. Med. Chem. 18 (2010)
J
2
1
2
4
.60 (d, J ¼ 3.2 Hz, 1 H, H-5), 4.39 (d, J ¼ 6.3 Hz, 1 H, H-11), 4.04 (d,
0
J ¼ 7.2 Hz,1 H, H-1 ), 3.72 (dd, J
1
¼ 20.4 Hz, J
2
¼ 16.0 Hz, 2 H, 3-O-CO-
0
CH
2
0
-), 3.64e3.57 (m, 1 H, 1 H-cyclopropyl), 3.27e3.15 (m, 2 H, H-5 ,
H-2 ), 3.05e2.63 (m, 10 H, 6-O-CO-CH
2
CH
2
eNHeCH
2
CH
2
C≡CeAr,
0
H-2, H-10), 2.52e2.43 (m, 1 H, H-3 ), 2.37e2.32 (m, 1 H, H-9a), 2.28
(
s, 6 H, -N(CH
3 2 3
) ), 2.15 (s, 3 H, -N-CH ), 2.08e2.01 (m, 1 H, H-4),
[
1
1
.97e1.86 (m, 3 H, H-9b, H-14eq, H-7a), 1.83e1.74 (m, 1 H, H-8),
0
.71e1.64 (m, 1 H, H-14ax), 1.64e1.60 (m, 1 H, H-4 a), 1.58 (s, 3 H, 6-
CH
3
), 1.48 (s, 3 H, 12-CH
3
), 1.45e1.39 (m, 2 H, 2 H-cyclopropyl),
[
[
[
0
1.27e1.23 (m, 1 H, H-7b), 1.23e1.19 (m, 3 H, H-4 b, 2 H-cyclopropyl),
0
1
.17 (d, J ¼ 6.2 Hz, 3 H, 5 -CH
J ¼ 6.5 Hz, 10-CH ), 0.96 (d, J ¼ 6.8 Hz, 2-CH
CH ), 0.90e0.86 (m, 3 H, 15-CH
78.1, 174.0, 172.5, 170.0, 166.7, 153.4, 150.4, 148.8, 148.1, 140.0, 137.1,
36.7, 129.9, 129.5, 125.9, 123.5, 122.5, 117.3, 109.0, 103.8, 91.2, 86.8,
3
),1.13 (d, J ¼ 7.4 Hz, 3 H, 4-CH
), 0.91 (d, J ¼ 6.9 Hz, 8-
). C NMR (CDCl , 100 MHz)
3
),1.06 (d,
3
3
13
3
3
3
d:
1
1
8
4
6.7, 84.4, 80.1, 79.8. 78.3, 77.2, 70.4, 69.7, 66.4, 66.0, 60.3, 48.2, 44.7,
3.4, 40.3, 38.5, 37.8, 36.9, 35.4, 35.2, 34.1, 28.3, 25.5, 21.7, 21.6, 21.2,
21.0, 20.6, 15.7, 15.2, 10.0, 9.6, 8.3, 7.4.
[
Declaration of competing interest
6
578e6588.
The authors declare that they have no known competing
financial interests or personal relationships that could have
appeared to influence the work reported in this paper.
[17] S. Kapic, H.C. Paljetak, S. Alihodzic, R. Antolovic, V.E. Haber, R.L. Jarvest,
D.J. Holmes, J.P. Broskey, E. Hunt, 6-Alkylquinolone-3-carboxylic acid tethered
to macrolides synthesis and antimicrobial profile, Bioorg. Med. Chem. 18
(2010) 6569e6577.
[
18] M.M. Skugor, V. Stimac, I. Palej, D. Lugaric, H.C. Paljetak, D. Filic, M. Modric,
I. Dilovic, D. Gembarovski, S. Mutak, V.E. Haber, D.J. Holmes, Z. Ivezic-
Schoenfeld, S. Alihodzic, Synthesis and biological activity of 4 ’’-O-acyl de-
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carboxylic unit, Bioorg. Med. Chem. 18 (2010) 6547e6558.
Acknowledgements
This work is financially supported by the National Natural Sci-
ence Foundation of China (81673335; 21878022) and National Key
Research and Development Program of China (2018YFA0901800).
This work during Liang’s visiting University of Minnesota is sup-
ported by China Scholarship Council. This work is also partially
supported by the National Natural Science Foundation of China
[19] A. Fajdetic, A. Vinter, H.C. Paljetak, J. Padovan, I.P. Jakopovic, S. Kapic,
S. Alihodzic, D. Filic, M. Modric, N. Kosutic-Hulita, R. Antolovic, Z.I. Schoenfeld,
S. Mutak, V.E. Haber, R. Spaventi, Synthesis, activity and pharmacokinetics of
novel antibacterial 15-membered ring macrolones, Eur. J. Med. Chem. 46
(2011) 3388e3397.
[
20] S. Kapic, H. Cipcic Paljetak, I. Palej Jakopovic, A. Fajdetic, M. Ilijas, V. Stimac,
K. Brajsa, D.J. Holmes, J. Berge, S. Alihodzic, Synthesis of macrolones with
central piperazine ring in the linker and its influence on antibacterial activity,
Bioorg. Med. Chem. 19 (2011) 7281e7298.
(
81761128016; 8187131584). The authors thank to Prof. Yun Li at
Peking University for their antibacterial assays. The authors also
appreciate the spectral data supporting from the Analysis & Testing
Center, Beijing Institute of Technology.
[
21] S. Kapic, A. Fajdetic, S. Kostrun, A. Cikos, H.C. Paljetak, R. Antolovic,
D.J. Holmes, S. Alihodzic, Synthesis and activity of new macrolones: conju-
gates between 6(7)-(2’-aminoethyl)-amino-1-cyclopropyl-3-carboxylic acid
(2’-hydroxyethyl) amides and 4-propenoyl-azithromycin, Bioorg. Med. Chem.
1
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Appendix A. Supplementary data
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