Synthesis and antibacterial activity of 4'3-O-(trans-β-arylacrylamido)carbamoyl azithromycin analogs

Article abstract of DOI:10.1016/j.ejmech.2015.09.020

Novel 4'3-O-(trans-β-arylacrylamido)carbamoyl azithromycin analogs were designed, synthesized and evaluated for their antibacterial activity against nine significant pathogens using broth microdilution method. A majority of these derivatives maintained the activity of azithromycin against susceptible Streptococcus pyogenes and all the compounds demonstrated remarkably improved activity compared with the references against all the three phenotypes of resistant Streptococcus pneumoniae. In particular, compound 24 exhibited the most potent activity against susceptible Staphylococcus aureus (MIC = 0.5 μg/mL), S. pneumoniae (MIC = 0.06 μg/mL) and S. pyogenes (MIC = 0.25 μg/mL). The most active compound 7 (MIC = 0.015 μg/mL) against resistant S. pneumoniae expressing the mefA gene, exhibited 512 and 256-fold more potent activity than erythromycin and azithromycin, respectively. Compounds 28 (MIC = 0.5 μg/mL), 29 (MIC = 0.25 μg/mL) and 30 (MIC = 0.5 μg/mL) demonstrated potent activity against resistant S. pneumoniae expressing the ermB gene, which were 256, 512 and 256-fold better than the references, respectively.

Full text of DOI:10.1016/j.ejmech.2015.09.020

European Journal of Medicinal Chemistry 103 (2015) 506e515
Contents lists available at ScienceDirect
European Journal of Medicinal Chemistry
journal homepage: http://www.elsevier.com/locate/ejmech
Short communication
Synthesis and antibacterial activity of 400-O-(trans-
b-arylacrylamido)
carbamoyl azithromycin analogs
Mi Yan a, Xiaodong Ma a, Ruiqian Dong b, Xin Li a, Can Zhao a, Zhenzhen Guo a, Yan Shen a,
,
*
Fang Liu a, Ruixin Ma c, Shutao Ma a
a Department of Medicinal Chemistry, Key Laboratory of Chemical Biology (Ministry of Education), School of Pharmaceutical Sciences,
Shandong University, 44 West Culture Road, Jinan 250012, China
b Maternity and Child Care Centre of Jinan, Jinan 250001, China
c Affiliated Hospital of Medical College, Qingdao University, Qingdao 266003, China
a r t i c l e i n f o
a b s t r a c t
Novel 400-O-(trans-
b-arylacrylamido)carbamoyl azithromycin analogs were designed, synthesized and
Article history:
Received 1 July 2015
Received in revised form
11 September 2015
Accepted 13 September 2015
Available online 15 September 2015
evaluated for their antibacterial activity against nine significant pathogens using broth microdilution
method. A majority of these derivatives maintained the activity of azithromycin against susceptible
Streptococcus pyogenes and all the compounds demonstrated remarkably improved activity compared
with the references against all the three phenotypes of resistant Streptococcus pneumoniae. In particular,
compound 24 exhibited the most potent activity against susceptible Staphylococcus aureus (MIC ¼ 0.5
mL), S. pneumoniae (MIC ¼ 0.06 g/mL) and S. pyogenes (MIC ¼ 0.25 g/mL). The most active compound 7
(MIC ¼ 0.015 g/mL) against resistant S. pneumoniae expressing the mefA gene, exhibited 512 and 256-
fold more potent activity than erythromycin and azithromycin, respectively. Compounds 28
g/mL) demonstrated potent activity
mg/
m
m
Keywords:
m
Antibacterial activity
Bacterial resistance
Evaluation
(MIC ¼ 0.5
m
g/mL), 29 (MIC ¼ 0.25
m
g/mL) and 30 (MIC ¼ 0.5
m
against resistant S. pneumoniae expressing the ermB gene, which were 256, 512 and 256-fold better than
the references, respectively.
Synthesis
400-O-(trans-
b-arylacrylamido)carbamoyl
azithromycin analogs
© 2015 Elsevier Masson SAS. All rights reserved.
1. Introduction
According to the size of the lactone ring, the macrolides are
divided into 14-membered, 15-membered and 16-membered
The macrolides are a group of typical antibiotics, the activity of
which stems from the macrolide ring, a large lactone ring to which
one or more deoxy sugars, usually cladinose or desosamine, are
attached [1]. First-generation macrolides, for example, erythro-
mycin A (EMA) (Fig. 1), are widely prescribed for upper and lower
respiratory tract infections, particularly for the patients who are
compounds [1]. A large number of chemical modifications of 14-
membered macrolides have been provided to eliminate antibacte-
rial resistance over the past years. Structureeactivity relationships
of 14-membered macrolides derivatives lead us to believe that the
aryl-alkyl groups attached to the lactone ring or the C-400 position of
the cladinose sugar structure are essential for overcoming macro-
lide-lincosamide-streptogramin B (MLSB) resistance, whereas the
11,12-cyclic carbamate or the 11,12-cyclic carbonate linkage is
important for overcoming efflux resistance. Azithromycin is the
first 15-membered macrolide that has a nitrogen atom incorpo-
rated into its lactone ring. It shares a similar mechanism of action to
the 14-membered macrolides that selectively bind to the 50S
subunit of bacterial ribosome resulting in the inhibition of protein
synthesis. Since azithromycin is inactive against resistant bacteria,
more research is needed to modify its chemical structure to get new
analogs with non-cross resistance [8].
drug resistant or allergic to b-lactam antibiotics [2]. Since eryth-
romycin may degrade under acidic conditions losing inherent ac-
tivity and the degraded products result in undesirable
gastrointestinal side effects, second-generation macrolides such as
azithromycin (AZM) (Fig. 1) [3,4] and clarithromycin (CAM) (Fig. 1)
[5,6] are discovered. However, the emergence of bacterial resis-
tance makes it an urgent need to develop newer generation of
macrolides that exhibit significant activity against resistant path-
ogens [7].
The two major mechanisms of macrolide resistance in Strepto-
coccus pneumonia are drug efflux pump encoded by the mef genes
* Corresponding author.
E-mail address: mashutao@sdu.edu.cn (S. Ma).
http://dx.doi.org/10.1016/j.ejmech.2015.09.020
0223-5234/© 2015 Elsevier Masson SAS. All rights reserved.

M. Yan et al. / European Journal of Medicinal Chemistry 103 (2015) 506e515
507
Fig. 1. Structures of erythromycin, azithromycin and clarithromycin.
and ribosome methylation resistance encoded by the erm genes. The
ermB gene encodes a methyltransferase, which dimethylates the key
nucleotide A2058 in the MLSB binding site [9]. The previous studies
indicated that 11-O-arylalkylcarbamoyl group of the macrolide de-
rivatives could interact with A752, and the 400-O-arylalkylcarbamoyl
group could interact with nucleotide binding sites between the PTC
and the macrolide roadblock. The interactions such as hydrogen
bonding, p-stacking and (or) electrostatic force increased affinity for
the resistant ribosome, thereby resulting in a remarkable improve-
ment in antibacterial activity against the Streptococcus pneumoniae
expressing the ermB gene. For example, EP-1553 (Fig. 1), an 11-O-
substituented clarithromycin analog, exhibited fairly good activity
against macrolide-resistant Streptococcus pyogenes, Staphylococcus
aureus and S. pneumonia while CP-544372 (Fig. 1) with the C-400 side
chain demonstrated excellent in vitro and in vivo activity against
susceptible and resistant bacteria.
corresponding aldehyde with malonic acid gave trans-
acids in the presence of pyridine through the Knoevenagel
condensation.
b
-arylacryl
2.2. Synthesis of 11,12-cyclic carbonate azithromycin 400-O-(trans-
b-arylacrylamido)carbamoyl analogs
The synthetic method for 11,12-cyclic carbonate azithromycin
400-O-(trans-
b-arylacrylamido)carbamoyl analogs is shown in
Scheme 2. Protection of the 20-hydroxyl group of azithromycin with
acetic anhydride provided 20-O-acetyl product (2) [10]. 11,12-
Carbonate 20-O-acetyl-400-O-acylimidazolide 3 was prepared in
toluene at 55 ꢀC by treatment of 2 with CDI in the presence of
triethylamine [8]. Then the acylimidazolide underwent a reaction
with hydrazine hydrate (85%), thus affording hydrazide product (4).
Finally, the hydrazide was converted to 11,12-cyclic carbonate azi-
thromycin
400-O-(trans-
b
-arylacrylamido)carbamoyl
analogs
On the basis of the consideration detailed above, we designed
and synthesized a series of novel 400-O-(trans-
b-arylacrylamido)
(5e16) by coupling with various trans-
b
-arylacryl acids in the
presence of sodium bicarbonate at 0 ꢀC followed by methanolysis.
carbamoyl azithromycin analogs with the 11,12-cyclic carbonate
ring or 11-O-arylalkylcarbamoyl side chains to enhance their anti-
resistant activity and broaden antibacterial spectrum. By intro-
duction of an arylacrylamido group into the 400-position of 11,12-
2.3. Synthesis of 11,400-di-O-arylalkylcarbamoyl azithromycin
analogs
cyclic carbonate azithromycin, the 400-O-(trans-
b-arylacrylamido)
The 11,12-cyclic carbonate azithromycin 400-O-(trans-
b-aryla-
carbamoyl azithromycin analogs were synthesized. It had been
reported that introduction of an arylalkyl group into the 400-posi-
tion or the 11-position of 15-membered macrolides enhances
antibacterial activity. By introduction of an arylacrylamido group
into the 400-position and C-11 position, the 11,400-di-O-ary-
lalkylcarbamoyl azithromycin analogs were synthesize [8].
crylamido)carbamoyl analogs were readily converted to novel
11,400-di-O-arylalkylcarbamoyl azithromycin analogs (17e33) by
reacting with the corresponding amines in the presence of pyridine
hydrochloride [8] (Scheme 2).
3. Antibacterial evaluation
2. Chemistry
All the synthesized compounds (5e33) were determined for
their in vitro antibacterial activity using the broth microdilution
method recommended by NCCL [11]. Minimal inhibitory concen-
tration (MIC) values for all tested compounds were determined in
2.1. Synthesis of trans-
b-arylacryl acids
The synthetic route is outlined in Scheme 1. The reaction of

508
M. Yan et al. / European Journal of Medicinal Chemistry 103 (2015) 506e515
Scheme 1. Synthetic route for L1eL12. Regents and Conditions: pyridine, reflux for 12 h.
comparison with azithromycin and clarithromycin on a panel of
sensitive and resistant Gram-positive bacterial strains. These
strains are S. aureus ATCC25923 (erythromycin-susceptible strain),
S. pneumoniae ATCC49619 (erythromycin-susceptible strain),
S. pyogenes S2 (erythromycin-susceptible strain isolated clinically),
S. aureus (penicillin-resistant strain isolated clinically, not charac-
terized), S. aureus ATCC29213 (methicillin-resistant strain),
S. pneumoniae B1 (erythromycin-resistant strain encoded by the
erm gene), S. pneumoniae A22072 (erythromycin-resistant strain
encoded by the mef gene), S. pneumoniae AB11 (erythromycin-
resistant strain encoded by the erm and mef genes), S. pyogenes R2
(erythromycin-resistant strain isolated clinically). The MIC results
are shown in Table 1.
addition, Compounds 28, 29 and 30 demonstrated potent activity
against resistant S. pneumoniae expressing the ermB gene, which
were 256, 512 and 256-fold better than the references, respectively.
We guessed that the 400-O-(trans-
b-arylacrylamido)carbamoyl can
fit well in the binding pocket of azithromycin in the bacterial
ribosome and impart additional affinity to the binding sites, which
lead to the restored activity against the erythromycin-susceptible
S. pneumoniae.
In particular, introduction of the prolonged 400-O-(trans-
b-ary-
lacrylamido)carbamoyl group further increased activity against
S. pneumoniae encoded by the mef genes. The prolonged 400-O-
(trans-b-arylacrylamido)carbamoyl group with nine atom dis-
tances from 400-oxygen atom to aromatic ring might reach the
chloramphenicol-binding sites and interact with them, resulting in
better binding to ribosomes in macrolide-resistant bacteria. And
the introduction of an arylalkylcarbamoyl group into the 11-
4. Results and discussion
position of the 400-O-(trans-
b-arylacrylamido)carbamoyl analogs
Almost all of the target compounds demonstrated remarkablely
improved activity compared with the references against all the
three phenotypes of resistant S. pneumoniae. Compounds 5, 10, 11,
13e16, 18e23 and 26e33, for example, displayed favorable activity
against resistant S. pneumoniae expressing the mefA gene, with MIC
improved their antibacterial activity against resistant bacteria. We
speculated that the C-11-arylalkylcarbamoyl side chain interacted
with the nucleotide A752 directly in domain II of the 23S rRNA in
addition to the main interaction with the nucleotide A2058, which
brought about an increased affinity for the resistant ribosome,
resulting in superior activity against the resistant S. pneumoniae.
On the whole, a majority of the target compounds maintained
the activity of AZM against susceptible S. pyogenes. Among them,
compound 24 exhibited the most potent activity against suscepti-
values between 0.03 and 0.5
mg/mL. In particular, the most active
compound 7 (MIC ¼ 0.015
m
g/mL) against resistant S. pneumoniae
expressing the mefA gene, exhibited 512 and 256-fold enhanced
activity than EMA and AZM, respectively. Moreover, Compounds 28
(MIC ¼ 0.5
m
g/mL), 29 (MIC ¼ 0.25
mg/mL) and 30 (MIC ¼ 0.5
mg/mL)
ble S. aureus (MIC ¼ 0.5
m
g/mL), S. pneumoniae (MIC ¼ 0.06
mg/mL)
demonstrated potent activity against resistant S. pneumoniae
expressing the ermB gene, which were 256, 512 and 256-fold better
than the references, respectively. In remarkable contrast, all of the
target compounds displayed weaker activity against penicillin-
resistant S. aureus than the references and a few of the target
compounds such as compounds 17 and 28 maintained the activity
of AZM against methicillin-resistant S. aureus. As for resistant
S. pneumoniae expressing the ermB and mefA genes, compounds 21
and S. pyogenes (MIC ¼ 0.25
m
g/mL). In the subseries of compounds
17e25, compound 21 showed the most potent activity against
S. aureus ATCC25923, S. pyogenes S2, S. pneumoniae B1,
S. pneumoniae AB11, S. pyogenes R2, respectively, while in the
subseries of compounds 26e33, compound 28 displayed the most
potent activity against S. aureus ATCC25923, S. pneumoniae
ATCC49619, S. pyogenes S2, S. aureus, S. aureus ATCC29213,
S. pneumoniae A22072, S. pneumoniae AB11, respectively. In addi-
tion, 11,400-di-O-arylalkylcarbamoyl analogs (17e33) displayed MIC
and 28e30 shared the identical activity with the MIC value of 1 mg/
mL, which was 256-fold lower than those of the references.
In addition, most of the target compounds showed improved
activity compared with the references against resistant S. pyogenes.
values below the susceptible level (MIC ꢁ 1
mg/mL) against sus-
ceptible S. aureus and S. pneumoniae, showing better antibacterial
activity than 11,12-cyclic carbonate 400-O-arylalkylcarbamoyl ana-
logs (5e16) against all the three tested susceptible strains. The
above results clearly indicated that introduction of arylalkylcarba-
Particularly, compound 29 had significant activity (MIC ¼ 4
mg/mL)
against erythromycin-resistant S. pyogenes, showing 32-fold
greater activity than the references.
moyl group into the 11-position of the 400-O-(trans-
b-arylacryla-
mido)carbamoyl analogs dramatically enhanced their antibacterial
activity against susceptible S. pyogenes, S. aureus and S. pneumoniae.
Besides, the 11,400-di-O-arylalkylcarbamoyl analogs 17e33
exhibited better activity against penicillin-resistant S. aureus and
methicillin-resistant S. aureus than 11,12-cyclic carbonate 400-O-
carbamoyl analogs 5e16. This clearly indicated that the introduc-
tion of an arylalkylcarbamoyl group into the 11-position of the 400-
5. Conclusions
O-(trans-
b
-arylacrylamido)carbamoyl
analogs,
dramatically
enhanced their antibacterial activity against resistant S. aureus.
Compounds 5, 10, 11, 13e16, 18e23 and 26e33 displayed
favorable activity against resistant S. pneumoniae expressing the
Novel 400-O-(trans-
b-arylacrylamido)carbamoyl azithromycin
analogs were designed, synthesized and tested for their in vitro
antibacterial activity against various phenotypes of Gram-positive
and Gram-negative bacteria species [12]. Generally, a majority of
mefA gene, with MIC values between 0.03 and 0.5
mg/mL. In

M. Yan et al. / European Journal of Medicinal Chemistry 103 (2015) 506e515
509
Scheme 2. Synthetic route for the synthesis of 400-O-(trans-
(b) CDI, Et3N, toluene, 55 ꢀC, 72 h; (c) NH2NH2$H2O (85%), rt, 0.5 h; (d) (COCl)2, DMF, THF, 0.5 h; (e) NaHCO3, THF, 2 h; CH3OH, 55 ꢀC, 12 h; (f) pyridine hydrochloride, rt, 72 h.
b-arylacrylamido)carbamoyl azithromycin analogs (5e33). Regents and Conditions: (a) (CH3CO)2O, CH2Cl2, Et3N, rt, 24 h;
the target compounds maintained the activity of AZM against
susceptible S. pyogenes, and significantly improved activity
compared with the references against resistant S. pyogenes and all
the three phenotypes of resistant S. pneumoniae. Compound 7 was
penicillin-resistant S. aureus and methicillin-resistant S. aureus.
These findings demonstrated that introduction of an ary-
lalkylcarbamoyl group into the 11-position of the 400-O-(trans-
b-
arylacrylamido)carbamoyl analogs dramatically enhanced their
activity against susceptible S. aureus, S. pneumoniae, S. pyogenes and
resistant S. aureus.
the most active compound (MIC ¼ 0.015
mg/mL) against resistant
S. pneumoniae expressing the mefA gene, exhibited 512 and 256-
fold better activity than EMA and AZM, respectively. Compounds
28 (MIC ¼ 0.5
m
g/mL), 29 (MIC ¼ 0.25
m
g/mL) and 30 (MIC ¼ 0.5
m
g/
6. Experimental
mL) demonstrated potent activity against resistant S. pneumoniae
expressing the ermB gene, which were 256, 512 and 256-fold better
than the references, respectively. In addition, 11,400-O-ary-
lalkylcarbamoyl analogs (compound 17e33) showed better anti-
All necessary solvents were purified prior to use, unless noted
otherwise. Reactions were monitored by thin-layer chromatog-
raphy (TLC) using 0.25-mm pre-coated silica gel plates (Qingdong
Yumingyuan silica gel reagent factory, Shandong, China, YUYUAN).
Flash chromatography was performed with the indicated solvents
using silica gel 60 (particle size 0.040e0.063 mm, Qingdong
bacterial
activity
than
11,12-cyclic
carbonate
400-O-
arylalkylcarbamoyl analogs (compound 5e16) against three sus-
ceptible strains of S. aureus, S. pneumoniae and S. pyogenes,

510
M. Yan et al. / European Journal of Medicinal Chemistry 103 (2015) 506e515
Table 1
400-O-(trans-
b-arylacrylamido)carbamoyl azithromycin analogs with their in vitro antibacterial activity against susceptible and resistant strains (mg/mL).
Compounds
S. aureus
S. pneumoniae
S. pyogenes
S. aureusd
S. aureus
S. pyogenes
S. pneumoniae
S. pneumoniae
S. pyogenes
ATCC25923a
ATCC49619b
S2c
ATCC29213e
R2f
A22072g
AB11h
R2i
5
6
7
8
8
2
32
2
4
8
4
4
2
2
8
8
0.5
1
1
2
8
8
16
8
4
4
16
2
4
2
4
0.5
0.12
0.5
0.5
0.25
0.25
0.5
0.06
0.5
0.25
0.5
0.25
0.5
0.25
1
0.25
0.25
0.25
0.5
0.25
1
1
0.5
0.25
8
0.5
8
4
64
16
16
8
8
8
16
8
8
16
1
1
2
2
2
2
2
2
8
8
64
8
8
8
4
8
8
4
16
16
1
4
4
4
2
2
2
4
4
4
4
1
2
2
8
4
4
0.12
1
8
32
2
64
16
8
0.25
1
0.015
2
4
16
4
16
32
8
4
64
8
2
8
16
4
8
64
ꢃ128
ꢃ128
64
64
32
9
2
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
EMA
AZM
0.5
0.25
2
0.5
0.25
0.5
0.5
1
0.12
0.06
0.25
0.12
0.12
0.5
2
8
16
64
16
4
32
32
2
4
2
4
1
ꢃ128
ꢃ128
64
64
64
32
64
32
16
16
16
32
64
64
32
64
32
0.5
0.5
0.25
0.25
0.5
0.25
0.5
0.25
0.25
1
0.25
0.25
0.25
0.5
4
2
1
2
1
0.5
0.5
0.5
0.5
1
1
1
0.5
0.5
1
4
1
2
0.06
0.25
4
16
64
32
2
8
64
16
8
8
1
1
1
8
8
4
4
2
2
2
2
8
4
2
0.25
0.25
0.03
0.12
0.25
0.5
0.25
0.25
8
2
0.5
0.25
0.5
2
4
2
4
16
32
64
0.5
0.25
0.25
0.5
0.12
0.25
0.25
0.5
0.03
0.03
4
0.25
0.12
8
256
256
64
128
128
ꢃ128
4
ꢃ128
a
S. aureus ATCC25923: erythromycin-susceptible strain.
b
c
d
e
f
S. pneumoniae ATCC49619: erythromycin-susceptible strain.
S. pyogenes S2: erythromycin-susceptible strain isolated clinically.
S. aureus: penicillin-resistant strain isolated clinically, not characterized.
S. aureus ATCC29213: methicillin-resistant strain.
S. pneumoniae B1: erythromycin-resistant strain encoded by the ermB gene.
S. pneumoniae A22072: erythromycin-resistant strain encoded by the mefA gene.
S. pneumoniae AB11: erythromycin-resistant strain encoded by the ermB and mefA genes.
S. pyogenes R2: erythromycin-resistant strain isolated clinically.
g
h
i
Yumingyuan silica gel reagent factory, Shandong, China, YUYUAN).
Infrared spectra were recorded on KBr pellets using Nicolet Nexus
470FT-IR spectrometer (Wisconsin, USA). 1H NMR spectra were
recorded on Bruker Avance DRX 600 spectrometer (Bruker, Swit-
zerlands) at ambient temperature (TMS as internal standard of
chemical shifts). Mass spectra were recorded on API 4000 instru-
ment (Applied Biosystems, Connecticut, USA). Melting points are
uncorrected and were determined on an X-6 melting point appa-
ratus (Beijing Tianchengwode Biotech Co. Ltd, Beijing, China). AZM
was used as starting material from Nexchem Pharmaceutical Co.
Ltd.
6.2. 20-O-Acetylazithromycin (2)
To a solution of azithromycin (2.0 g, 2.67 mmol) in dichloro-
methane (20 mL) at room temperature was added acetic anhydride
(0.5 mL, 5.34 mmol) and Et3N (1.48 mL, 10.68 mmol). The resulting
solution was allowed to stir for 24 h at the same temperature. The
reaction was quenched with saturated NaHCO3 (20 mL) and the
aqueous layer was extracted with dichloromethane (3 ꢂ 10 mL).
The combined organic layers were dried over anhydrous Na2SO4,
filtered, and concentrated in vacuum. The residue was crystallized
from acetoneewater (2:1) to afford 1.84 g (92%) of 19 as a white
solid: mp 167e170 ꢀC; Rf
¼
0.52 (dichloromethane/
methanol ¼ 10:1); MS (ESI) m/z calcd. For C40H74N2O13 791.0; found
(M þ Hþ) 792.3.
6.1. General methods for trans-b-arylacryl acids (L1eL12)
To a solution of benzaldehyde (1.06 g, 10 mmol) in pyridine
(20 mL) was added malonic acid (2.08 g, 20 mmol). The resulting
solution was allowed to stir at 118 ꢀC and reflux for 2 h. Afterward,
the solution was concentrated in vacuum to remove pyridine and
the residue was quenched with saturated NaHCO3. Washed with
ethyl acetate (15mL ꢂ 2), the aqueous layer was subsequently
adjusted to pH ¼ 1 using concentrated hydrochloric acid and
afforded 0.77 g (52%) of L1 as light-yellow precipitates, Rf ¼ 0.30
(petroleum ether/ethyl acetate/acetic acid ¼ 30:10:1). According to
6.3. 20-O-acetyl-400-O-acylimidazolylazithromycin 11,12-cyclic
carbonate (3)
To a solution of 2 (1.5 g, 1.90 mmol) in toluene (20 mL) was
added Et3N (0.68 mL, 4.33 mmol) and CDI (1.23 g, 7.60 mmol). The
resulting solution was heated to 55 ꢀC and stirred at the same
temperature for 72 h. The reaction was quenched with saturated
NaHCO3 (40 mL) and the aqueous layer was extracted with toluene
(3 ꢂ 10 mL). The combined organic layers were dried over anhy-
drous Na2SO4, filtered, and concentrated in vacuum. The residue
the above procedure, corresponding trans-
b-arylacryl acids L2eL12
were prepared in yields ranging from 52% to 58%.

M. Yan et al. / European Journal of Medicinal Chemistry 103 (2015) 506e515
511
was purified by flash column chromatography (dichloromethane/
methanol, 20:1) to afford 1.61 g (93%) of 20 as a white solid: mp
117e120 ꢀC; Rf ¼ 0.61 (dichloromethane/methanol ¼ 10:1); MS
(ESI) m/z calcd. for C45H74N4O15 911.1; found (M þ Hþ) 912.4.
2832, 2788, 1815, 1741, 1685, 1635, 1579, 1461, 1383, 1276, 1219,
1168, 1112, 1045, 1014 cm###1; 1H NMR (600 MHz, CDCl3): 7.69 (d,
1H, J ¼ 15.6 Hz), 7.46e7.45 (m, 2H), 7.36e7.35 (m, 3H), 6.46 (d, 1H,
J ¼ 15.6 Hz), 5.07 (s, 1H), 4.89e4.87 (m, 1H), 4.62e4.61 (m, 1H),
4.47e4.41 (m, 4H), 3.68 (s, 1H), 3.60e3.59 (m, 1H), 3.31 (s, 4H),
2.86e2.84 (m, 2H), 2.71 (s, 1H), 2.44e2.32 (m, 8H), 2.21 (s, 3H),
2.07e1.99 (m, 2H),1.92 (s,1H),1.85e1.81 (m, 2H),1.65e1.55 (m, 3H),
1.44e1.40 (m, 4H), 1.32e1.19 (m, 18H), 1.07e1.04 (m, 7H), 0.99e0.91
(m, 7H); MS (ESI) m/z calcd. for C49H78N4O15 962.5; found (M þ Hþ)
963.9.
6.4. General methods for the key intermediate (4)
To a solution of 3 (3.0 g, 3.30 mmol) in DMF (20 mL) was added
hydrazine hydrate (85%) (0.29 g, 4.95 mmol). The resulting solution
was stirred for 0.5 h at room temperature. The reaction was
quenched with saturated NaHCO3 and the aqueous layer was
extracted with ethyl acetate (2 ꢂ 15 mL). The combined organic
layers were washed with brine, and dried over anhydrous Na2SO4,
filtered. The filtrate was concentrated in vacuum to afford a crude
product of 400-O-aminocarbamate 4 (95.6%): Rf ¼ 0.62 (dichloro-
methane/methanol ¼ 10:1).
6.6.2. 400-O-[Trans-
b-(2-furyl)acrylamido]carbamoyl azithromycin
11,12-cyclic carbonate (6)
White solids, yield 69.2%, mp 143e146 ꢀC, TLC Rf ¼ 0.41
(CH2Cl2:MeOH ¼ 10:1); IR (KBr): 3598, 3469, 2973, 2937, 2873,
2789, 1815, 1741, 1681, 1624, 1461, 1382, 1276, 1217, 1167, 1112, 1044
cmꢄ1; 1H NMR (600 MHz, CDCl3): 7.95 (d, 1H, J ¼ 15.6 Hz),
7.46e7.45 (m, 1H), 7.34e7.32 (m, 1H), 6.95e6.93 (m, 1H), 6.61 (d,
1H, J ¼ 15.6 Hz), 5.05 (s, 1H), 4.89e4.87 (m, 1H), 4.62e4.60 (m, 1H),
4.51 (d, 1H, J ¼ 5.4 Hz), 4.34e4.31 (m, 3H), 3.72 (s, 1H), 3.60 (d, 1H,
J ¼ 5.4 Hz), 3.38e3.36 (m, 1H), 3.28e3.23 (m, 3H), 2.86e2.85 (m,
2H), 2.81 (s, 1H), 2.64e2.57 (m, 5H), 2.44e2.36 (m, 3H), 2.20 (s, 3H),
2.06e2.01 (m, 2H), 1.91 (s, 1H), 1.85e1.81 (m, 2H), 1.66e1.57 (m,
3H), 1.45e1.43 (m, 4H), 1.32e1.17 (m, 18H), 1.08e1.03 (m, 7H),
6.5. General methods for 11,12-cyclic carbonate azithromycin 400-O-
(trans-b-arylacrylamido)carbamoyl analogs (5e16)
To a solution of L1 (0.41 g, 2.74 mmol) in THF was added oxalyl
chloride (1.03 g, 8.22 mmol) drop by drop and DMF (three drops) at
0
ꢀC. The resulting solution was stirred for 0.5 h at the same tem-
perature. Subsequently, the reaction was quenched in vacuum to
remove THF and oxalyl chloride and afforded light-yellow residue.
A solution of the key intermediate 4 (3 g, 3.43 mmol) and
NaHCO3 (0.23 g, 2.74 mmol) in anhydrous THF was stirred at 0 ꢀC.
After addition of the above residue in THF drop by drop, the
resulting solution was stirred for another 2 h at the same temper-
ature. Then the reaction was concentrated in vacuum to remove
THF and quenched with saturated NaHCO3. Subsequently, the
aqueous layer was extracted with ethyl acetate (2 ꢂ 25 mL) and the
combined organic layer was washed with brine, dried over anhy-
drous Na2SO4 and filtered. The filtrate was concentrated in vacuum
to afford a crude product. A solution of the above crude product in
methanol was heated to 55 ꢀC and stirred for 12 h at the same
temperature. Subsequent concentration of the reaction solution in
vacuum provided the crude product of 5. The above crude product
was purified by flash column chromatography eluting with 30:1
dichloromethane/methanol to afford the desired product 5. Ac-
cording to the above procedure, corresponding compounds 6e16
were prepared in yields ranging from 66% to 73%.
0.96e0.88 (m, 7H); 13C NMR (100 MHz, CDCl3)
d 177.25, 153.38,
150.98, 144.51, 129.52, 114.85, 114.61, 112.24, 103.12, 95.32, 85.94,
85.10, 80.59, 78.04, 76.34, 73.52, 73.28, 70.73, 68.48, 67.52, 65.22,
63.00, 61.20, 49.51, 45.28, 43.14, 41.90, 40.25, 35.26, 34.29, 29.01,
26.88, 26.23, 22.08, 22.01, 21.44, 21.02, 17.65, 14.91, 14.14, 10.81,
10.39, 5.49; MS (ESI) m/z calcd. for C47H76N4O16 952.5; found
(M þ Hþ) 953.9.
6.6.3. 400-O-[Trans-
b-(2-thienyl)acrylamido]carbamoyl
azithromycin 11,12-cyclic carbonate (7)
White solids, yield 71.2%, mp 149e151 ꢀC, TLC Rf ¼ 0.43
(CH2Cl2:MeOH ¼ 10:1); IR (KBr): 3597, 3468, 2974, 2937, 2875,
2833, 2788, 1816, 1741, 1682, 1625, 1461, 1383, 1276, 1217, 1168, 1112,
1045, 1014 cmꢄ1; 1H NMR (600 MHz, CDCl3): 7.79 (d, 1H,
J ¼ 15.6 Hz), 7.35e7.33 (m, 1H), 7.20e7.19 (m, 1H), 7.03e7.01 (m,
1H), 6.26 (d, 1H, J ¼ 15.6 Hz), 5.07 (s, 1H), 4.89e4.88 (m, 1H),
4.62e4.60 (m, 1H), 4.48e4.39 (m, 4H), 3.68 (s, 1H), 3.60e3.59 (m,
1H), 3.31 (s, 4H), 2.89e2.86 (m, 2H), 2.73 (s, 1H), 2.44e2.36 (m, 8H),
2.20 (s, 3H), 2.06e2.00 (m, 2H), 1.91 (s, 1H), 1.85e1.80 (m, 2H),
1.66e1.60 (m, 3H), 1.44e1.37 (m, 4H), 1.33e1.19 (m, 18H), 1.07e1.06
6.6. General methods for 11,400-di-O-arylalkylcarbamoyl
azithromycin analogs (17e33)
(m, 7H), 0.94e0.86 (m, 7H); MS (ESI) m/z calcd. for C47H76N4O15
S
968.5; found (M þ Hþ) 969.8.
To a solution of 5 (0.50 g, 0.52 mmol) in benzylamine (2.22 mL)
was added pyridine hydrochloride (0.17 g, 0.47 mmol). The result-
ing solution was stirred for 72 h at the room temperature. After-
wards, the reaction was quenched by the addition of ethyl acetate
(2 ꢂ 15 mL) and saturated NaH2PO4 (10 mL). Subsequently, the
combined organic layer was washed with brine, dried over anhy-
drous Na2SO4 and filtered. The filtrate was concentrated in vacuum
to give a crude product, which was subjected to flash column
chromatography eluting with 20:1 dichloromethane/methanol to
afford the desired product 17.
6.6.4. 400-O-[Trans-
azithromycin 11,12-cyclic carbonate (8)
b-(4-flourophenyl)acrylamido]carbamoyl
White solids, yield 70.3%, mp 162e165 ꢀC, TLC Rf ¼ 0.37
(CH2Cl2:MeOH ¼ 10:1); IR (KBr): 3600, 3530, 3273, 2972, 2933,
2857, 2787, 1816, 1740, 1679, 1635, 1601, 1461, 1382, 1230, 1166, 1111,
1045 cmꢄ1; 1H NMR (600 MHz, CDCl3): 7.62 (d, 1H, J ¼ 15.6 Hz),
7.44e7.43 (m, 2H), 7.04e7.02 (m, 2H), 6.41 (d, 1H, J ¼ 15.6 Hz), 5.06
(s, 1H), 4.88e4.87 (m, 1H), 4.61e4.60 (m, 1H), 4.41e4.37 (m, 4H),
3.70e3.67 (m, 1H), 3.59 (s, 1H), 3.35e3.31 (m, 4H), 2.87e2.84 (m,
2H), 2.83 (s, 1H), 2.58e2.35 (m, 8H), 2.21 (s, 3H), 2.03e1.78 (m, 5H),
1.66e1.56 (m, 3H), 1.47e1.41 (m, 4H), 1.34e1.22 (m, 18H), 1.08e1.05
(m, 7H), 0.95e0.91 (m, 7H); MS (ESI) m/z calcd. for C49H77FN4O15
980.5; found (M þ Hþ) 982.1.
According to the above procedure, compounds 18e25, 26e33
were prepared in yields ranging from 61% to 73% by condensation of
corresponding compounds selected from 5e16 with benzyl amine
and 4-methoxybenzyl amine respectively.
6.6.1. 400-O-(Trans-
b
-phenylacrylamido)carbamoyl azithromycin
6.6.5. 400-O-[Trans-
b-(2-flourophenyl)acrylamido]carbamoyl
11,12-cyclic carbonate (5)
azithromycin 11,12-cyclic carbonate (9)
White solids, yield 70.8%, mp 158e160 ꢀC, TLC Rf ¼ 0.38
(CH2Cl2:MeOH ¼ 10:1); IR (KBr): 3596, 3466, 2975, 2939, 2879,
White solids, yield 65.7%, mp 159e163 ꢀC, TLC Rf ¼ 0.44
(CH2Cl2:MeOH ¼ 10:1); IR (KBr): 3599, 3524, 3294, 2975, 2940,

512
M. Yan et al. / European Journal of Medicinal Chemistry 103 (2015) 506e515
2879, 2832, 2789, 1816, 1741, 1689, 1636, 1579, 1460, 1383, 1230,
1168, 1111, 1045, 1015 cmꢄ1; 1H NMR (600 MHz, CDCl3): 7.78 (d, 1H,
J ¼ 15.6 Hz), 7.46e7.45 (m,1H), 7.33e7.32 (m,1H), 7.14e7.12 (m,1H),
7.07e7.04 (m, 1H), 6.59 (d, 1H, J ¼ 15.6 Hz), 5.08 (s, 1H), 4.89e4.88
(m, 1H), 4.62e4.61 (m, 1H), 4.47e4.42 (m, 4H), 3.67 (s, 1H),
3.60e3.59 (m, 1H), 3.35e3.25 (m, 4H), 2.86e2.85 (m, 2H), 2.65 (s,
1H), 2.44e2.37 (m, 8H), 2.20 (s, 3H), 2.07e1.99 (m, 2H), 1.91 (s, 1H),
1.85e1.80 (m, 2H), 1.66e1.56 (m, 3H), 1.48e1.40 (m, 4H), 1.33e1.19
(m, 18H), 1.07e1.05 (m, 7H), 0.93e0.90 (m, 7H); 13C NMR (100 MHz,
1168, 1111, 1045, 1014 cmꢄ1; 1H NMR (600 MHz, CDCl3): 8.21e8.19
(m, 2H), 7.67e7.64 (m, 1H), 7.59e7.57 (m, 2H), 6.65e6.63 (m, 1H),
5.09 (s, 1H), 4.89 (d, 1H, J ¼ 9.6 Hz), 4.63 (d, 1H, J ¼ 9.6 Hz),
4.46e4.41 (m, 4H), 3.66 (s, 1H), 3.60e3.58 (m, 1H), 3.34e3.28 (m,
4H), 2.89e2.85 (m, 2H), 2.66 (s, 1H), 2.45e2.35 (m, 8H), 2.21 (s, 3H),
2.08e2.00 (m, 2H), 1.93 (m, 1H), 1.85e1.80 (m, 2H), 1.67e1.55 (m,
3H), 1.47e1.37 (m, 4H), 1.33e1.15 (m, 18H), 1.09e0.90 (m, 14H); MS
(ESI) m/z calcd. for C49H77N5O17 1007.5; found (M þ Hþ) 1008.9.
CDCl3)
d
177.20, 162.65, 160.13, 153.39, 135.92, 131.42, 129.48,
6.6.10. 400-O-[Trans-
b-(2-methoxyphenyl)acrylamido]carbamoyl
124.44, 119.85, 116.22, 116.00, 103.21, 95.37, 85.90, 85.13, 80.83,
78.06, 76.32, 73.49, 73.2, 70.77, 68.54, 67.55, 65.26, 62.98, 61.20,
49.53, 45.29, 43.20, 41.89, 40.28, 35.29, 34.31, 28.91, 26.87, 26.25,
22.09, 22.01, 21.48, 21.03, 17.66, 14.90, 14.18, 10.83, 10.40, 5.53; MS
(ESI) m/z calcd. for C49H77FN4O15 980.5; found (M þ Hþ) 981.9.
azithromycin 11,12-cyclic carbonate (14)
Light-yellow solids, yield 72.3%, mp 156e159 ꢀC, TLC Rf ¼ 0.43
(CH2Cl2:MeOH ¼ 10:1); IR (KBr): 3598, 3524, 2973, 2937, 2877,
2788, 1815, 1741, 1685, 1629, 1578, 1463, 1383, 1220, 1167, 1111, 1046
cmꢄ1; 1H NMR (600 MHz, CDCl3): 7.47e7.45 (m, 2H), 6.82e6.78 (m,
1H), 6.57e6.55 (m, 1H), 6.46e6.43 (m, 1H), 6.38e6.34 (m, 1H), 5.07
(s, 1H), 4.89e4.87 (m, 1H), 4.62e4.59 (m, 1H), 4.48e4.41 (m, 4H),
3.83 (s, 3H), 3.67 (s, 1H), 3.60e3.58 (m, 1H), 3.34e3.31 (m, 4H),
2.89e2.85 (m, 2H), 2.69 (s, 1H), 2.54e2.27 (m, 8H), 2.22 (s, 3H),
2.08e1.96 (m, 2H), 1.91 (s, 1H), 1.85e1.80 (m, 2H), 1.68e1.51 (m,
3H), 1.48e1.35 (m, 4H), 1.34e0.80 (m, 32H); MS (ESI) m/z calcd. for
6.6.6. 400-O-[Trans-
b-(4-chlorophenyl)acrylamido]carbamoyl
azithromycin 11,12-cyclic carbonate (10)
White solids, yield 71.1%, mp 161e163 ꢀC, TLC Rf ¼ 0.43
(CH2Cl2:MeOH ¼ 10:1); IR (KBr): 3596, 3524, 3271, 2975, 2939,
2879, 2832, 2788, 1815, 1741, 1678, 1634, 1593, 1461, 1383, 1220,
1168, 1111, 1045 cmꢄ1; 1H NMR (600 MHz, CDCl3): 7.56 (d, 1H,
J ¼ 15.6 Hz), 7.35e7.34 (m, 2H), 7.32e7.30 (m, 2H), 6.48 (d, 1H,
J ¼ 15.6 Hz), 5.07 (s, 1H), 4.89e4.86 (m, 1H), 4.62e4.60 (m, 1H),
4.49e4.35 (m, 4H), 3.68 (s, 1H), 3.59 (s, 1H), 3.31e3.26 (m, 4H),
2.89e2.83 (m, 2H), 2.73 (s, 1H), 2.44e2.34 (m, 8H), 2.23e2.21 (m,
3H), 2.07e1.99 (m, 2H),1.92 (s,1H),1.85e1.80 (m, 2H),1.65e1.56 (m,
3H), 1.46e1.39 (m, 4H), 1.36e1.18 (m, 18H), 1.12e1.05 (m, 7H),
0.98e0.90 (m, 7H); MS (ESI) m/z calcd. for C49H77ClN4O15 996.5;
found (M þ Hþ) 998.0.
C
50H80N4O16 992.6; found (M þ Hþ) 993.9.
6.6.11. 400-O-[Tans-
b-(3,4-dimethoxyphenyl)acrylamido]carbamoyl
azithromycin 11,12-cyclic carbonate (15)
White solids, yield 69.5%, mp 155e159 ꢀC, TLC Rf ¼ 0.41
(CH2Cl2:MeOH ¼ 10:1); IR (KBr): 3598, 3525, 3341, 2972, 2921,
2850, 2788, 1815,1741, 1685, 1631, 1464,1383,1263,1219,1167,1112,
1045 cmꢄ1; 1H NMR (600 MHz, CDCl3): 7.57 (d, 1H, J ¼ 15.6 Hz),
7.00 (d, 1H, J ¼ 9.0 Hz), 6.93 (s, 1H), 6.81 (d, 1H, J ¼ 9.0 Hz), 6.46 (d,
1H, J ¼ 15.6 Hz), 5.10 (s, 1H), 4.91e4.87 (m, 1H), 4.62e4.60 (m, 1H),
4.48e4.40 (m, 4H), 3.93e3.76 (m, 6H), 3.67 (s, 1H), 3.63e3.55 (m,
1H), 3.36e3.27 (m, 4H), 2.87e2.85 (m, 2H), 2.67 (s, 1H), 2.44e2.32
(m, 8H), 2.21e2.17 (m, 3H), 2.08e1.96 (m, 2H), 1.92 (s, 1H),
1.85e1.80 (m, 2H), 1.65e1.55 (m, 3H), 1.45e1.39 (m, 4H), 1.34e1.16
(m, 18H), 1.13e0.82 (m, 14H); MS (ESI) m/z calcd. for C51H82N4O17
1022.6; found (M þ Hþ) 1024.1.
6.6.7. 400-O-[Trans-
b-(4-bromophenyl)acrylamido]carbamoyl
azithromycin 11,12-cyclic carbonate (11)
White solids, yield 73.2%, mp 162e165 ꢀC, TLC Rf ¼ 0.36
(CH2Cl2:MeOH ¼ 10:1); IR (KBr): 3595, 3525, 2974, 2938, 2879,
2831, 2788, 1815, 1740, 1685, 1634, 1588, 1461, 1383, 1264, 1220,
1168, 1111, 1072, 1045 cmꢄ1; 1H NMR (600 MHz, CDCl3): 7.57 (d, 1H,
J ¼ 15.6 Hz), 7.47e7.45 (m, 2H), 7.28e7.27 (m, 2H), 6.46 (d, 1H,
J ¼ 15.6 Hz), 5.08 (s, 1H), 4.89e4.87 (m, 1H), 4.62e4.60 (m, 1H),
4.48e4.43 (m, 4H), 3.68e3.66 (m, 1H), 3.61e3.59 (m, 1H),
3.33e3.31 (m, 4H), 2.88e2.83 (m, 2H), 2.65 (s, 1H), 2.40e2.31 (m,
8H), 2.21 (s, 3H), 2.07e1.99 (m, 2H), 1.92 (s, 1H), 1.85e1.81 (m, 2H),
1.66e1.54 (m, 3H), 1.45e1.39 (m, 4H), 1.33e1.19 (m, 18H), 1.07e1.03
(m, 7H), 0.99e0.90 (m, 7H); MS (ESI) m/z calcd. for C49H77BrN4O15
1040.5; found (M þ Hþ) 1043.7.
6.6.12. 400-O-[Trans-
b-(3,4,5-trimethoxyphenyl)acrylamido]
carbamoyl azithromycin 11,12-cyclic carbonate (16)
White solids, yield 71.6%, mp 154e157 ꢀC, TLC Rf ¼ 0.43
(CH2Cl2:MeOH ¼ 10:1); IR (KBr): 3598, 3525, 3306, 2973, 2939,
2876, 2836, 2788, 1815, 1741, 1678, 1633, 1583, 1461, 1383, 1268,
1219, 1168,1045, 1013 cmꢄ1; 1H NMR (600 MHz, CDCl3): 7.45 (d, 1H,
J ¼ 15.6 Hz), 6.57 (s, 2H), 6.34 (d, 1H, J ¼ 15.6 Hz), 5.09 (s, 1H),
4.88e4.86 (m, 1H), 4.62e4.60 (m, 1H), 4.49e4.45 (m, 4H),
3.86e3.83 (m, 9H), 3.62 (s, 1H), 3.60e3.58 (m, 1H), 3.35e3.27 (m,
4H), 2.88e2.85 (m, 2H), 2.64 (s, 1H), 2.44e2.33 (m, 8H), 2.21 (s, 3H),
2.08e2.00 (m, 2H), 1.92 (s, 1H), 1.84e1.76 (m, 2H), 1.68e1.58 (m,
3H), 1.48e1.38 (m, 4H), 1.33e1.19 (m, 18H), 1.08e0.90 (m, 14H); MS
(ESI) m/z calcd. for C52H84N4O18 1052.6; found (M þ Hþ) 1054.0.
6.6.8. 400-O-[Trans-
b-(4-cyanophenyl)acrylamido]carbamoyl
azithromycin 11,12-cyclic carbonate (12)
White solids, yield 67.9%, mp 164e166 ꢀC, TLC Rf ¼ 0.42
(CH2Cl2:MeOH ¼ 10:1); IR (KBr): 3596, 3525, 2975, 2939, 2880,
2832, 2788, 2229, 1814, 1740, 1685, 1637, 1605, 1461, 1384, 1274,
1223, 1169, 1112, 1044 cmꢄ1; 1H NMR (600 MHz, CDCl3): 7.65e7.62
(m, 2H), 7.60e7.58 (m, 2H), 7.54e7.52 (m, 1H), 6.63e6.61 (m, 1H),
5.05e5.04 (m, 1H), 4.89e4.86 (m, 1H), 4.60e4.56 (m, 2H),
4.43e4.30 (m, 3H), 3.74e3.71 (m, 1H), 3.59e3.57 (m, 1H),
3.48e3.44 (m, 1H), 3.33 (s, 3H), 3.30 (s, 1H), 2.96 (s, 1H), 2.89e2.77
(m, 8H), 2.47e2.44 (m, 1H), 2.39e2.36 (m, 1H), 2.22 (s, 3H),
2.15e1.80 (m, 6H), 1.64e1.56 (m, 3H), 1.51e0.82 (m, 34H); MS (ESI)
m/z calcd. for C50H77N5O15 987.5; found (M þ Hþ) 988.9.
6.6.13. 400-O-(Trans-
b-phenylacrylamido)carbamoyl-11-O-benzyl
carbamoyl azithromycin (17)
White solids, yield 73.1%, mp 155e157 ꢀC, TLC Rf ¼ 0.20
(CH2Cl2:MeOH ¼ 5:1); IR (KBr): 3459, 3311, 2974, 2937, 2875, 2789,
1732, 1635, 1528, 1456, 1382, 1170, 1112, 1045, 1015 cmꢄ1; 1H NMR
(600 MHz, CDCl3): 7.75e7.70 (m, 1H), 7.55e7.50 (m, 2H), 7.42e7.40
(m, 2H), 7.35e7.33 (m, 3H), 7.24e7.22 (m, 3H), 6.52e6.50 (m, 1H),
5.07e5.05 (m, 1H), 4.97 (s, 1H), 4.85 (s, 1H), 4.51e4.43 (m, 3H),
4.33e4.31 (m, 1H), 3.73e3.72 (m, 2H), 3.67 (s, 2H), 3.36e3.27 (m,
4H), 3.25 (s, 2H), 2.63e2.55 (m, 3H), 2.36e2.33 (m, 6H), 2.29 (s, 3H),
2.17e2.15 (m, 2H), 2.03 (s, 2H),1.97e1.88 (m, 3H),1.76e1.75 (m,1H),
6.6.9. 400-O-[Trans-
b-(4-nitrophenyl)acrylamido]carbamoyl
azithromycin 11,12-cyclic carbonate (13)
Yellow solids, yield 68.5%, mp 138e140 ꢀC, TLC Rf ¼ 0.45
(CH2Cl2:MeOH ¼ 10:1); IR (KBr): 3598, 3526, 2975, 2939, 2878,
2832, 2788, 1815, 1741, 1689, 1637, 1599, 1461, 1383, 1275, 1220,
1.63 (s, 2H), 1.58e1.55 (m, 2H), 1.47 (s, 1H), 1.33e0.87 (m, 33H); 13
NMR (100 MHz, CDCl3) 176.62, 143.03, 138.88, 134.47, 130.93,
C
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M. Yan et al. / European Journal of Medicinal Chemistry 103 (2015) 506e515
513
130.09, 128.88, 128.84, 128.62, 128.50, 128.03, 126.51, 126.38, 117.26,
104.01, 96.40, 80.44, 79.23, 75.28, 73.91, 73.21, 70.57, 68.90, 65.22,
63.38, 61.97, 49.66, 45.63, 42.98, 42.37, 41.76, 40.36, 36.00, 35.51,
30.57, 29.63, 27.48, 26.24, 21.77, 21.22, 21.02, 19.18, 17.39, 14.41,
11.46, 10.61, 9.79; MS (ESI) m/z calcd. for C56H87N5O15 1069.6; found
(M þ Hþ) 1070.9.
6.6.18. 400-O-[Trans-
benzyl carbamoyl azithromycin (22)
b-(4-nitrophenyl)acrylamido]carbamoyl-11-O-
White solids, yield 69.8%, mp 143e145 ꢀC, TLC Rf ¼ 0.20
(CH2Cl2:MeOH ¼ 5:1); IR (KBr): 3323, 2974, 1813, 1731, 1637, 1599,
1522, 1458, 1381, 1344, 1169, 1111, 1043 cmꢄ1; 1H NMR (600 MHz,
CDCl3): 8.24e8.21 (m, 3H), 7.76e7.72 (m, 2H), 7.31e7.30 (m, 2H),
7.23e7.20 (m, 3H), 7.11e7.09 (m, 1H), 5.08 (s, 1H), 4.96 (s, 1H), 4.82
(s, 1H), 4.52e4.46 (m, 3H), 4.28e4.26 (m, 1H), 3.70e3.68 (m, 2H),
3.66 (s, 2H), 3.40e3.34 (m, 4H), 3.24 (s, 2H), 2.61e2.55 (m, 3H),
2.33e2.30 (m, 6H), 2.24 (s, 3H), 2.15e2.13 (m, 2H), 2.00 (s, 2H),
1.98e1.87 (m, 3H), 1.71e1.70 (m, 1H), 1.57 (s, 2H), 1.55e1.53 (m, 2H),
1.43 (s,1H),1.28e0.93 (m, 33H); MS (ESI) m/z calcd. for C56H86N6O17
1114.6; found (M þ Hþ) 1116.2.
6.6.14. 400-O-[Trans-
b-(2-furyl)acrylamido]carbamoyl-11-O-benzyl
carbamoyl azithromycin (18)
White solids, yield 65.4%, mp 141e144 ꢀC, TLC Rf ¼ 0.23
(CH2Cl2:MeOH ¼ 5:1); IR (KBr): 3311, 2974, 2936, 1812, 1731, 1639,
1529, 1456, 1382, 1168, 1110, 1074, 1043, 1015 cmꢄ1; 1H NMR
(600 MHz, CDCl3): 7.80e7.76 (m, 1H), 7.45e7.39 (m, 2H), 7.37e7.30
(m, 5H), 6.46e6.42 (m, 1H), 6.38e6.35 (m, 1H), 5.09 (s, 1H),
4.99e4.97 (m, 1H), 4.82 (s, 1H), 4.53e4.47 (m, 3H), 4.31e4.28 (m,
1H), 3.70e3.69 (m, 2H), 3.63 (s, 2H), 3.30e3.21 (m, 4H), 3.18 (s, 2H),
2.61e2.57 (m, 3H), 2.37e2.34 (m, 6H), 2.30 (s, 3H), 2.18e2.16 (m,
2H), 1.98 (s, 2H), 1.94e1.86 (m, 3H), 1.74e1.73 (m, 1H), 1.61 (s, 2H),
1.56e1.53 (m, 2H), 1.43 (s, 1H), 1.35e0.90 (m, 33H); MS (ESI) m/z
calcd. for C54H85N5O16 1059.6; found (M þ Hþ) 1061.4.
6.6.19. 400-O-[Trans-
b-(2-methoxyphenyl)acrylamido]carbamoyl-
11-O-benzyl carbamoyl azithromycin (23)
White solids, yield 70.3%, mp 153e155 ꢀC, TLC Rf ¼ 0.19
(CH2Cl2:MeOH ¼ 5:1); IR (KBr): 3309, 2975, 2937, 2836, 1812, 1730,
1642, 1578, 1517, 1455, 1382, 1344, 1168, 1123, 1045 cmꢄ1; 1H NMR
(600 MHz, CDCl3): 7.95 (d, 1H, J ¼ 15.6 Hz), 7.78e7.76 (m, 1H),
7.38e7.34 (m, 3H), 7.22e7.16 (m, 2H), 7.02e6.76 (m, 3H), 6.60 (d,
1H, J ¼ 15.6 Hz), 5.06 (s, 1H), 4.99 (s, 1H), 4.85 (s, 1H), 4.53e4.48 (m,
3H), 4.30e4.28 (m, 1H), 3.83e3.80 (m, 3H), 3.71e3.69 (m, 2H), 3.63
(s, 2H), 3.37e3.34 (m, 4H), 3.20 (s, 2H), 2.57e2.54 (m, 3H),
2.30e2.27 (m, 6H), 2.23 (s, 3H), 2.11e2.09 (m, 2H), 1.99 (s, 2H),
1.96e1.89 (m, 3H),1.70e1.68 (m,1H),1.55 (s, 2H),1.53e1.51 (m, 2H),
1.45 (s,1H),1.27e0.98 (m, 33H); MS (ESI) m/z calcd. for C57H89N5O16
1099.6; found (M þ Hþ) 1101.1.
6.6.15. 400-O-[Trans-
b-(2-thienyl)acrylamido]carbamoyl-11-O-
benzyl carbamoyl azithromycin (19)
White solids, yield 70.5%, mp 146e150 ꢀC, TLC Rf ¼ 0.18
(CH2Cl2:MeOH ¼ 5:1); IR (KBr): 3322, 2973, 2936, 1814, 1733, 1624,
1521, 1458, 1380, 1168, 1112, 1045 cmꢄ1; 1H NMR (600 MHz, CDCl3):
7.85e7.83 (m, 1H), 7.77e7.75 (m, 1H), 7.57e7.55 (m, 1H), 7.53e7.51
(m, 1H), 7.32e7.30 (m, 2H), 7.26e7.24 (m, 3H), 6.89e6.86 (m, 1H),
5.05 (s, 1H), 4.95e4.93 (m, 1H), 4.79 (s, 1H), 4.48e4.43 (m, 3H),
4.27e4.25 (m, 1H), 3.65e3.64 (m, 2H), 3.58 (s, 2H), 3.25e3.19 (m,
4H), 3.16 (s, 2H), 2.58e2.55 (m, 3H), 2.34e2.31 (m, 6H), 2.28 (s, 3H),
2.16e2.13 (m, 2H), 1.96 (s, 2H), 1.91e1.83 (m, 3H), 1.76e1.73 (m, 1H),
1.58 (s, 2H), 1.53e1.51 (m, 2H), 1.41 (s, 1H), 1.37e0.89 (m, 33H); MS
(ESI) m/z calcd. for C54H85N5O15S 1075.6; found (M þ Hþ) 1077.2.
6.6.20. 400-O-[Trans-
b-(3,4-dimethoxyphenyl)acrylamido]
carbamoyl-11-O-benzyl carbamoyl azithromycin (24)
White solids, yield 72.4%, mp 152e154 ꢀC, TLC Rf ¼ 0.20
(CH2Cl2:MeOH ¼ 5:1); IR (KBr): 3463, 2973, 2936, 1815, 1734, 1632,
1600, 1516, 1459, 1383, 1343, 1167, 1112, 1046 cmꢄ1; 1H NMR
(600 MHz, CDCl3): 7.36e7.33 (m, 3H), 7.26e7.23 (m, 4H), 7.18e7.16
(m, 1H), 6.88e6.87 (m, 2H), 5.09e5.07 (m, 1H), 4.95 (s, 1H), 4.87 (s,
1H), 4.55e4.50 (m, 3H), 4.33e4.31 (m, 1H), 3.82e3.81 (m, 6H),
3.73e3.71 (m, 2H), 3.66 (s, 2H), 3.39e3.36 (m, 4H), 3.22 (s, 2H),
2.55e2.53 (m, 3H), 2.31e2.29 (m, 6H), 2.25 (s, 3H), 2.10e2.07 (m,
2H), 1.98 (s, 2H), 1.93e1.83 (m, 3H), 1.72e1.71 (m, 1H), 1.57 (s, 2H),
1.55e1.53 (m, 2H), 1.49 (s, 1H), 1.25e0.99 (m, 33H); MS (ESI) m/z
calcd. for C58H91N5O17 1129.6; found (M þ Hþ) 1131.4.
6.6.16. 400-O-[Trans-
b-(4-chloropheny)acrylamido]carbamoyl-11-
O-benzyl carbamoyl azithromycin (20)
White solids, yield 71.4%, mp 156e158 ꢀC, TLC Rf ¼ 0.22
(CH2Cl2:MeOH ¼ 5:1); IR (KBr): 3461, 3316, 2975, 2937, 2876, 2832,
2788, 1815, 1733, 1635, 1592, 1458, 1382, 1169, 1112, 1045, 1014
cmꢄ1; 1H NMR (600 MHz, CDCl3): 7.65e7.63 (m, 1H), 7.60e7.58 (m,
2H), 7.43e7.41 (m, 2H), 7.31e7.30 (m, 2H), 7.26e7.23 (m, 3H),
6.53e6.38 (m, 1H), 5.02e5.00 (m, 1H), 4.94 (s, 1H), 4.83 (s, 1H),
4.50e4.40 (m, 3H), 4.30e4.28 (m, 1H), 3.73e3.72 (m, 2H), 3.63 (s,
2H), 3.35e3.25 (m, 4H), 3.21 (s, 2H), 2.61e2.52 (m, 3H), 2.35e2.31
(m, 6H), 2.25 (s, 3H), 2.18e2.16 (m, 2H), 2.01 (s, 2H), 1.95e1.85 (m,
3H), 1.74e1.72 (m, 1H), 1.60 (s, 2H), 1.52e1.50 (m, 2H), 1.44 (s, 1H),
1.30e0.90 (m, 33H); MS (ESI) m/z calcd. for C56H86ClN5O15 1103.6;
found (M þ Hþ) 1105.4.
6.6.21. 400-O-[Trans-
b-(3,4,5-trimethoxyphenyl)acrylamido]
carbamoyl-11-O-benzyl carbamoyl azithromycin (25)
White solids, yield 70.2%, mp 151e154 ꢀC, TLC Rf ¼ 0.18
(CH2Cl2:MeOH ¼ 5:1); IR (KBr): 3501, 3308, 2975, 2937, 2835, 1812,
1731, 1641, 1583, 1504, 1456, 1382, 1328, 1168, 1043, 1011 cmꢄ1; 1H
NMR (600 MHz, CDCl3): 7.42e7.40 (m, 3H), 7.32e7.29 (m, 3H),
6.90e6.88 (m, 1H), 6.80 (s, 2H), 5.06 (s, 1H), 4.97e4.95 (m, 1H), 4.85
(s, 1H), 4.53e4.50 (m, 3H), 4.30e4.29 (m, 1H), 3.80 (m, 9H),
3.73e3.71 (m, 2H), 3.64 (s, 2H), 3.37e3.35 (m, 4H), 3.26 (s, 2H),
2.57e2.55 (m, 3H), 2.30e2.28 (m, 6H), 2.25 (s, 3H), 2.09e2.06 (m,
2H), 1.95 (s, 2H), 1.90e1.80 (m, 3H), 1.73e1.72 (m, 1H), 1.55 (s, 2H),
1.51e1.49 (m, 2H), 1.45 (s, 1H), 1.33e1.00 (m, 33H); 13C NMR
6.6.17. 400-O-[Trans-
b-(4-bromophenyl)acrylamido]carbamoyl-11-
O-benzyl carbamoyl azithromycin (21)
White solids, yield 70.6%, mp 158e160 ꢀC, TLC Rf ¼ 0.22
(CH2Cl2:MeOH ¼ 5:1); IR (KBr): 3455, 2973, 2933, 1814, 1732, 1635,
1587, 1458, 1381, 1169, 1112, 1045 cmꢄ1; 1H NMR (600 MHz, CDCl3):
7.65e7.62 (m, 2H), 7.51e7.48 (m, 2H), 7.39e7.37 (m, 1H), 7.33e7.31
(m, 2H), 7.24e7.21 (m, 3H), 6.79e6.77 (m, 1H), 5.08 (s, 1H), 4.95 (s,
1H), 4.79 (s, 1H), 4.52e4.43 (m, 3H), 4.25e4.23 (m, 1H), 3.68e3.66
(m, 2H), 3.64 (s, 2H), 3.38e3.31 (m, 4H), 3.22 (s, 2H), 2.59e2.53 (m,
3H), 2.35e2.31 (m, 6H), 2.26 (s, 3H), 2.18e2.16 (m, 2H), 2.04 (s, 2H),
1.99e1.89 (m, 3H), 1.73e1.72 (m, 1H), 1.56 (s, 2H), 1.53e1.51 (m, 2H),
1.42 (s, 1H), 1.21e0.91 (m, 33H); MS (ESI) m/z calcd. for
(100 MHz, CDCl3)
d 176.67, 153.34, 139.87, 138.98, 137.79, 130.08,
128.87, 128.70, 128.48, 127.54, 126.71, 126.35, 105.27, 103.76, 96.25,
80.34, 79.20, 75.18, 74.02, 73.31, 70.54, 68.74, 65.19, 62.09, 61.76,
60.93, 56.17, 49.64, 45.68, 42.41, 40.29, 35.99, 31.72, 29.66, 27.32,
26.33, 21.89, 21.21, 21.03, 19.25, 17.45, 14.50, 11.38, 10.37, 9.78; MS
(ESI) m/z calcd. for C59H93N5O18 1159.7; found (M þ Hþ) 1161.0.
6.6.22. 400-O-(Trans-
b-phenylacrylamido)carbamoyl-11-O-(4-
methoxybenzyl)carbamoyl azithromycin (26)
C
56H86BrN5O15 1147.5; found (M þ Hþ) 1148.8.
White solids, yield 71.2%, mp 146e149 ꢀC, TLC Rf ¼ 0.25

514
M. Yan et al. / European Journal of Medicinal Chemistry 103 (2015) 506e515
(CH2Cl2:MeOH ¼ 5:1); IR (KBr): 3321, 2974, 2835, 1812, 1731, 1638,
1608, 1580, 1513, 1461, 1381, 1340, 1170, 1110, 1036 cmꢄ1; 1H NMR
(600 MHz, CDCl3): 7.72e7.67 (m, 2H), 7.48e7.44 (m, 2H), 7.37e7.32
(m, 2H), 7.28e7.22 (m, 2H), 6.89e6.80 (m, 3H), 5.02e5.00 (m, 1H),
4.93e4.92 (m, 1H), 4.65 (s, 1H), 4.43e4.34 (m, 3H), 4.24e4.22 (m,
1H), 3.84e3.82 (m, 3H), 3.67e3.65 (m, 2H), 3.57 (s, 2H), 3.29e3.21
(m, 4H), 3.17e3.15 (m, 2H), 2.55e2.50 (m, 3H), 2.29e2.23 (m, 6H),
2.19 (s, 3H), 2.12e2.10 (m, 2H), 2.01 (s, 2H), 1.89e1.82 (m, 3H),
1.68e1.66 (m, 1H), 1.58 (s, 2H), 1.49e1.47 (m, 2H), 1.40 (s, 1H),
1.33e0.88 (m, 33H); MS (ESI) m/z calcd. for C57H89N5O16 1099.6;
found (M þ Hþ) 1101.3.
3.28e3.24 (m, 4H), 3.18e3.15 (m, 2H), 2.54e2.52 (m, 3H), 2.31e2.26
(m, 6H), 2.23 (s, 3H), 2.12e2.10 (m, 2H), 1.98 (s, 2H), 1.87e1.83 (m,
3H), 1.67e1.65 (m, 1H), 1.57e1.54 (m, 2H), 1.49e1.47 (m, 2H),
1.37e1.35 (m, 1H), 1.32e0.93 (m, 33H); MS (ESI) m/z calcd. for
C
57H88BrN5O16 1177.5; found (M þ Hþ) 1180.9.
6.6.27. 400-O-[Trans-
b-(4-nitrophenyl)acrylamido]carbamoyl-11-O-
(4-methoxybenzyl)carbamoyl azithromycin (31)
Light-yellow solids, yield 67.6%, mp 134e138 ꢀC, TLC Rf ¼ 0.20
(CH2Cl2:MeOH ¼ 5:1); IR (KBr): 3341, 2974, 2938, 1731, 1635, 1612,
1517, 1461, 1382, 1345, 1172, 1111, 1039 cmꢄ1; 1H NMR (600 MHz,
CDCl3): 8.20e8.18 (m,1H), 7.76e7.71 (m,1H), 7.66 (d,1H, J ¼ 7.8 Hz),
7.27e7.24 (m, 4H), 7.23 (d, 1H, J ¼ 7.8 Hz), 6.89e6.87 (m, 2H),
5.05e5.03 (m, 1H), 4.96 (s, 1H), 4.73e4.71 (m, 1H), 4.50e4.47 (m,
3H), 4.31e4.28 (m, 1H), 3.89e3.86 (m, 3H), 3.72e3.70 (m, 2H),
3.59e3.57 (m, 2H), 3.27e3.23 (m, 4H), 3.19e3.17 (m, 2H), 2.55e2.51
(m, 3H), 2.32e2.24 (m, 6H), 2.20 (s, 3H), 2.15e2.13 (m, 2H), 1.97 (s,
2H), 1.85e1.82 (m, 3H), 1.69e1.67 (m, 1H), 1.59e1.56 (m, 2H),
1.50e1.48 (m, 2H), 1.39e1.38 (m, 1H), 1.29e0.79 (m, 33H); 13C NMR
6.6.23. 400-O-[Trans-
b-(2-furyl)acrylamido]carbamoyl-11-O-(4-
methoxybenzyl)carbamoyl azithromycin (27)
White solids, yield 68.4%, mp 133e137 ꢀC, TLC Rf ¼ 0.25
(CH2Cl2:MeOH ¼ 5:1); IR (KBr): 3321, 2973, 2937, 2836, 1811, 1730,
1637, 1608, 1579, 1513, 1462, 1382, 1338, 1168, 1110, 1035 cmꢄ1; 1H
NMR (600 MHz, CDCl3): 7.47e7.45 (m, 2H), 7.24e7.22 (m, 3H),
6.89e6.87 (m, 2H), 6.59e6.57 (m, 1H), 6.47e6.45 (m, 1H),
5.04e5.02 (m, 1H), 4.96e4.94 (m, 1H), 4.68 (s, 1H), 4.45e4.38 (m,
3H), 4.25e4.22 (m, 1H), 3.86e3.84 (m, 3H), 3.68e3.66 (m, 2H), 3.59
(s, 2H), 3.28e3.23 (m, 4H), 3.18e3.15 (m, 2H), 2.54e2.51 (m, 3H),
2.31e2.25 (m, 6H), 2.21 (s, 3H), 2.11e2.08 (m, 2H), 2.03 (s, 2H),
1.87e1.83 (m, 3H), 1.67e1.65 (m, 1H), 1.56 (s, 2H), 1.48e1.45 (m,
2H), 1.38 (s, 1H), 1.30e0.85 (m, 33H); MS (ESI) m/z calcd. for
(100 MHz, CDCl3)
d 176.68, 167.77, 164.46, 158.22, 148.47, 130.93,
129.83, 128.85, 128.63, 124.16, 113.95, 104.09, 96.49, 75.35, 73.93,
70.60, 65.58, 65.22, 55.29, 49.66, 45.65, 42.56, 40.31, 35.71, 35.10,
30.58, 29.75, 21.03, 19.18, 17.39, 14.34, 13.72, 11.48; MS (ESI) m/z
calcd. for C57H88N6O18 1144.6; found (M þ Hþ) 1146.1.
C
55H87N5O17 1089.6; found (M þ Hþ) 1091.4.
6.6.28. 400-O-[Trans-
b-(2-methoxyphenyl)acrylamido]carbamoyl-
11-O-(4-methoxybenzyl) carbamoyl azithromycin (32)
6.6.24. 400-O-[Trans-
b-(2-thienyl)acrylamido]carbamoyl-11-O-(4-
White solids, yield 70.4%, mp 143e147 ꢀC, TLC Rf ¼ 0.22
(CH2Cl2:MeOH ¼ 5:1); IR (KBr): 3463, 2973, 2836, 1815, 1732, 1614,
1514, 1462, 1381, 1171, 1110, 1046 cmꢄ1; 1H NMR (600 MHz, CDCl3):
7.97 (d, 1H, J ¼ 15.6 Hz), 7.47 (d, 2H, J ¼ 7.2 Hz), 7.36e7.33 (m, 2H),
7.24 (d, 2H, J ¼ 7.2 Hz), 6.87e6.85 (m, 2H), 6.59 (d, 1H, J ¼ 15.6 Hz),
5.07e5.05 (m, 1H), 4.99 (s, 1H), 4.76e4.74 (m, 1H), 4.55e4.52 (m,
3H), 4.33e4.30 (m, 1H), 3.87e3.85 (m, 6H), 3.71e3.69 (m, 2H),
3.57e3.55 (m, 2H), 3.28e3.25 (m, 4H), 3.21e3.18 (m, 2H),
2.53e2.49 (m, 3H), 2.31e2.25 (m, 6H), 2.18 (s, 3H), 2.14e2.11 (m,
2H), 2.03 (s, 2H),1.87e1.85 (m, 3H),1.71e1.68 (m,1H),1.57e1.55 (m,
2H), 1.52e1.50 (m, 2H), 1.41e1.39 (m, 1H), 1.36e0.86 (m, 33H); MS
(ESI) m/z calcd. for C58H91N5O17 1129.6; found (M þ Hþ) 1131.2.
methoxybenzyl)carbamoyl azithromycin (28)
White solids, yield 71.5%, mp 142e144 ꢀC, TLC Rf ¼ 0.22
(CH2Cl2:MeOH ¼ 5:1); IR (KBr): 3323, 2974, 2835, 1814, 1733, 1618,
1586, 1514, 1461, 1381, 1246, 1171, 1111, 1042 cmꢄ1; 1H NMR
(600 MHz, CDCl3): 7.36e7.34 (m, 1H), 7.25e7.23 (m, 2H), 7.21e7.18
(m, 1H), 7.05e7.03 (m, 1H), 6.99e6.97 (m, 1H), 6.88e6.83 (m, 3H),
5.06e5.04 (m, 1H), 4.93 (s, 1H), 4.68e4.67 (m, 1H), 4.47e4.42 (m,
3H), 4.27e4.24 (m, 1H), 3.88e3.85 (m, 3H), 3.67e3.65 (m, 2H),
3.59e3.57 (m, 2H), 3.26e3.21 (m, 4H), 3.16e3.13 (m, 2H), 2.52e2.49
(m, 3H), 2.30e2.24 (m, 6H), 2.20 (s, 3H), 2.10e2.08 (m, 2H), 1.99 (s,
2H), 1.85e1.81 (m, 3H), 1.66e1.64 (m, 1H), 1.55e1.53 (m, 2H),
1.47e1.44 (m, 2H), 1.39e1.37 (m, 1H), 1.33e0.88 (m, 33H); MS (ESI)
m/z calcd. for C55H87N5O16S 1105.6; found (M þ Hþ) 1107.1.
6.6.29. 400-O-[Trans-
b-(3,4-dimethoxyphenyl)acrylamido]
carbamoyl-11-O-(4-methoxybenzyl) carbamoyl azithromycin (33)
White solids, yield 66.2%, mp 142e146 ꢀC, TLC Rf ¼ 0.25
(CH2Cl2:MeOH ¼ 5:1); IR (KBr): 3501, 2974, 2836, 1813, 1733, 1630,
1514, 1463, 1381, 1168, 1110, 1040 cmꢄ1; 1H NMR (600 MHz, CDCl3):
7.65e7.63 (m, 1H), 7.22e7.16 (m, 3H), 7.07e7.05 (m, 1H), 6.88e6.83
(m, 4H), 5.08e5.05 (m, 1H), 4.96 (s, 1H), 4.73e4.71 (m, 1H),
4.52e4.48 (m, 3H), 4.32e4.31 (m, 1H), 3.83e3.81 (m, 9H),
3.70e3.68 (m, 2H), 3.55e3.53 (m, 2H), 3.30e3.27 (m, 4H),
3.22e3.20 (m, 2H), 2.54e2.52 (m, 3H), 2.32e2.26 (m, 6H),
2.20e2.18 (m, 3H), 2.13e2.09 (m, 2H), 2.01e1.99 (m, 2H), 1.85e1.83
(m, 3H), 1.71e1.69 (m, 1H), 1.58e1.56 (m, 2H), 1.53e1.51 (m, 2H),
1.42e1.40 (m, 1H), 1.43e0.94 (m, 33H); 13C NMR (100 MHz, CDCl3)
6.6.25. 400-O-[Trans-
b-(4-chlorophenyl)acrylamido]carbamoyl-11-
O-(4-methoxybenzyl)carbamoyl azithromycin (29)
White solids, yield 69.5%, mp 148e152 ꢀC, TLC Rf ¼ 0.24
(CH2Cl2:MeOH ¼ 5:1); IR (KBr): 3319, 2937, 1813, 1732, 1634, 1590,
1514, 1461, 1380, 1172, 1092, 1040 cmꢄ1; 1H NMR (600 MHz, CDCl3):
7.66e7.63 (m, 1H), 7.41e7.33 (m, 5H), 7.27e7.25 (m, 2H), 7.24e7.23
(m, 2H), 5.02e5.00 (m, 1H), 4.93e4.92 (m, 1H), 4.65 (s, 1H),
4.43e4.34 (m, 3H), 4.24e4.22 (m, 1H), 3.84e3.82 (m, 3H),
3.67e3.65 (m, 2H), 3.57 (s, 2H), 3.29e3.21 (m, 4H), 3.17e3.15 (m,
2H), 2.55e2.50 (m, 3H), 2.29e2.23 (m, 6H), 2.19 (s, 3H), 2.12e2.10
(m, 2H), 2.01 (s, 2H), 1.89e1.82 (m, 3H), 1.68e1.66 (m, 1H), 1.58 (s,
2H), 1.49e1.47 (m, 2H), 1.40 (s, 1H), 1.33e0.88 (m, 33H); MS (ESI) m/
z calcd. for C57H88ClN5O16 1133.6; found (M þ Hþ) 1135.2.
d
176.65, 165.58, 158.18, 151.22, 149.27, 130.97, 130.28, 129.83,
129.37, 129.29, 127.36, 122.38, 113.93, 111.09, 109.90, 75.26, 73.82,
73.19, 70.66, 69.02, 65.23, 63.31, 61.96, 55.97, 55.90, 55.28, 49.68,
45.55, 43.07, 42.56, 40.35, 35.12, 29.71, 29.25, 27.54, 21.76, 21.30,
21.02, 17.33, 14.35, 11.48; MS (ESI) m/z calcd. for C59H93N5O18
1159.7; found (M þ Hþ) 1161.3.
6.6.26. 400-O-[Trans-
b-(4-bromophenyl)acrylamido]carbamoyl-11-
O-(4-methoxybenzyl)carbamoyl azithromycin (30)
White solids, yield 72.1%, mp 149e152 ꢀC, TLC Rf ¼ 0.20
(CH2Cl2:MeOH ¼ 5:1); IR (KBr): 3459, 2973, 2936, 1814, 1730, 1636,
1610, 1585, 1514, 1461, 1380, 1170, 1111, 1042 cmꢄ1; 1H NMR
(600 MHz, CDCl3): 7.65e7.62 (m, 1H), 7.51e7.48 (m, 2H), 7.36e7.34
(m, 2H), 7.26e7.22 (m, 5H), 5.03e5.01 (m, 1H), 4.95 (s, 1H),
4.70e4.67 (m, 1H), 4.45e4.43 (m, 3H), 4.28e4.25 (m, 1H),
3.87e3.84 (m, 3H), 3.69e3.67 (m, 2H), 3.61e3.59 (m, 2H),
Acknowledgments
This research was supported financially by the National Natural
Science Foundation of China (21072114), the Natural Science
Foundation of Shandong (ZR2015BM019), and ChinaeAustralia

M. Yan et al. / European Journal of Medicinal Chemistry 103 (2015) 506e515
515
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