Combating fluconazole-resistant fungi with novel β-azole-phenylacetone derivatives

Article abstract of DOI:10.1016/j.ejmech.2019.111689

A series of β-azole-phenylacetone derivatives with novel structures were designed and synthesized to combat the increasing incidence of susceptible fungal infections and drug-resistant fungal infections. The antifungal activity of the synthesized compounds was assessed against five susceptible strains and five fluconazole-resistant strains. Antifungal activity tests showed that most of the compounds exhibited excellent antifungal activities against five pathogenic strains with MIC values in the range of 0.03–1 μg/mL. Compounds with R¹ = 3-F substituted and 15o and 15ae exhibited moderate antifungal activities against fluconazole-resistant strains 17# and CaR with MIC values in the range of 1–8 μg/mL. Compounds with R¹ = H or 2-F (such as 15a, 15o, 15p) displayed moderate to good antifungal activity against fluconazole-resistant strains 632, 901 and 904 with MIC values in the range of 0.125–4 μg/mL. Notably, 15o and 15ae exhibited antifungal activity against five susceptible strains and five fluconazole-resistant strains. Preliminary mechanistic studies showed that the potent antifungal activity of compound 15ae stemmed from inhibition of C. albicans CYP51. Compounds 15o, 15z and 15ae were nearly nontoxic to mammalian A549 cells.

Full text of DOI:10.1016/j.ejmech.2019.111689

European Journal of Medicinal Chemistry 183 (2019) 111689
Contents lists available at ScienceDirect
European Journal of Medicinal Chemistry
journal homepage: http://www.elsevier.com/locate/ejmech
Research paper
Combating fluconazole-resistant fungi with novel b-azole-
phenylacetone derivatives
Liyu Zhao a, Nannan Sun a, Linfeng Tian a, Yin Sun a, Yixuan Chen a, Xinran Wang a,
,
Shizhen Zhao b, Xin Su c, Dongmei Zhao a *, Maosheng Cheng a
a Key Laboratory of Structure-Based Drug Design and Discovery, Ministry of Education, School of Pharmaceutical Engineering, Shenyang Pharmaceutical
University, 103 Wenhua Road, Shenhe District, Shenyang, 110016, China
b Key Laboratory of Receptors-Mediated Gene Regulation and Drug Discovery, School of Medicine, Henan University, Kaifeng, 475004, China
c The School of Life Science and Biopharmaceutical, Shenyang Pharmaceutical University, 103 Wenhua Road, Shenhe District, Shenyang, 110016, China
a r t i c l e i n f o
a b s t r a c t
Article history:
A series of b-azole-phenylacetone derivatives with novel structures were designed and synthesized to
Received 28 July 2019
Received in revised form
6 September 2019
Accepted 7 September 2019
Available online 13 September 2019
combat the increasing incidence of susceptible fungal infections and drug-resistant fungal infections. The
antifungal activity of the synthesized compounds was assessed against five susceptible strains and five
fluconazole-resistant strains. Antifungal activity tests showed that most of the compounds exhibited
excellent antifungal activities against five pathogenic strains with MIC values in the range of 0.03e1 mg/
mL. Compounds with R1 ¼3-F substituted and 15o and 15ae exhibited moderate antifungal activities
against fluconazole-resistant strains 17# and CaR with MIC values in the range of 1e8 mg/mL. Compounds
Keywords:
CYP51
Azole antifungals
Structure-activity relationship
Fluconazole-resistance
with R1 ¼ H or 2-F (such as 15a, 15o, 15p) displayed moderate to good antifungal activity against
fluconazole-resistant strains 632, 901 and 904 with MIC values in the range of 0.125e4 mg/mL. Notably,
15o and 15ae exhibited antifungal activity against five susceptible strains and five fluconazole-resistant
strains. Preliminary mechanistic studies showed that the potent antifungal activity of compound 15ae
stemmed from inhibition of C. albicans CYP51. Compounds 15o, 15z and 15ae were nearly nontoxic to
mammalian A549 cells.
© 2019 Elsevier Masson SAS. All rights reserved.
1. Introduction
inhibiting fungal lanosterol 14a-demethylase (CYP51) [10e14].
Fluconazole, a typical azole antifungal agent, has been used in the
clinic for almost thirty years. Given its high therapeutic index and
more favorable safety profile, fluconazole has been used as a first-
line antifungal agent and some derivatives have been developed,
for example, itraconazole, voriconazole and albaconazole (Fig. 1).
However, the widespread use of azole agents leads to severe drug
resistance, which has significantly decreased the therapeutic effi-
cacy. The mechanism of drug resistance mainly includes: (1)
overexpression or gene mutation of CYP51 [15,16] (2) upregulation
of drug excretion genes (e.g., CDR1, CDR2 and MDR1); [17]; (3) the
formation of biofilm [18]. Severe drug resistance has promoted
ongoing discoveries azole antifungal agents with novel structures,
low toxicity and high efficiency.
During the past decades, the incidence of systemic fungal in-
fections has increased dramatically, due to the growing number of
immunocompromised patients, such as cancer patients undergoing
chemotherapy or organ transplant and patients with AIDS [1e4].
Candida spp., Cryptococcus neoformans and Aspergillus spp. are the
three major invasive fungal pathogens [5]. Among them, Candida
albicans causes the most common fungal infections. Currently,
antifungal agents in the clinic can be divided into four classes ac-
cording to the mode of action: polyenes (e.g., amphotericin B and
nystatin) [6], azoles (e.g., fluconazole and itraconazole) [7], echi-
nocandins (e.g., caspofungin and micafungin) [8], and antimetab-
olites (e.g., 5-fluorocytosine) [9].
Among them, azole agents can block the biosynthesis of
ergosterol (a very important component of cell membrane) by
Previously, a number of azole derivatives in our compound li-
brary were screened and evaluated for their in vitro antifungal ac-
tivity according to the protocols of the Clinical Laboratory Standard
Institute (CLSI). Compound 5 has a novel
b-azole-phenylacetone
scaffold, and it showed excellent antifungal activity against five
* Corresponding author.
E-mail address: medchemzhao@163.com (D. Zhao).
https://doi.org/10.1016/j.ejmech.2019.111689
0223-5234/© 2019 Elsevier Masson SAS. All rights reserved.

2
L. Zhao et al. / European Journal of Medicinal Chemistry 183 (2019) 111689
Fig. 1. Chemical structures of azole antifungal agents and lead compound 5.
susceptible strains but was inactive against fluconazole-resistant
strains 17# and CaR, which were isolated from AIDS patients. To
discover compounds with activity against both five susceptible
strains and five fluconazole-resistant strains and to explore the
structure-activity relationship, a series of
b-azole-phenylacetone
derivatives have been designed and synthesized and their in vitro
antifungal activity against susceptible strains and fluconazole-
resistant strains was analyzed. The antifungal activity result
showed that most compounds exhibited excellent antifungal ac-
tivity against the five susceptible strains with MIC values in the
range of 0.03e1 mg/mL. For the fluconazole-resistant strains, com-
pounds 15b, 15q, 15t and 15z with R1 ¼3-F substitution and 15o
and 15ae showed moderate antifungal activity against fluconazole-
resistant strains 17# and CaR with MIC values in the range of
1e8
m
g/mL. Compounds with R1 ¼ H or 2-F substitution, such as
15a, 15o, 15p, displayed moderate to good antifungal activity
against fluconazole-resistant strains 632, 901 and 904 with MIC
values in the range of 0.125e4 mg/mL. Notably, 15o and 15ae
exhibited antifungal activity against five susceptible strains and five
fluconazole-resistant strains.
Scheme 1. Synthesis of intermediates 8a-n. Reagents and conditions: (a) Pd(PPh3)4,
K2CO3, dioxane, reflux, 5 h.
were synthesized via amide reaction of amino 14a-g and acid 8a-n
in DMF at room temperature.
2. Results and discussion
As depicted in Scheme 3, the triazole derivative 18 was syn-
thesized using procedures similar to those described above, except
that 1,10-Carbonyl-di(1,2,4-triazole) and triazole were used instead
of CDI and imidazole.
2.1. Chemistry
The synthetic route of key intermediates 8a-n was illustrated in
Scheme 1. Commercially available substituted 4-bromobenzoic acid
6a-g and substituted phenylboronic 7a-i were reacted to afford 8a-
n via a palladium-catalyzed Suzuki coupling reaction [19].
2.2. In vitro antifungal activity
Target compounds 15a-ae were prepared according the pro-
cedures shown in Scheme 2. The bromoacetophenones 9a-g were
reacted with hexamethylenetetramine and then refluxed in the
presence of 37% HCl to afford the amino derivatives 10a-g. The
amino derivatives 10a-g were protected with (Boc)2O, and com-
pounds 11a-g were obtained. Treatment of compounds 11a-g with
formaldehyde and NaHCO3 in MeOH/H2O afforded hydroxy com-
pounds 12a-g [20]. Compounds 12a-g were reacted with CDI and
imidazole to form imidazole derivatives 13a-g, and then cleavage of
the Boc protecting group of compounds 13a-g with hydrochloric
acid gave amino derivatives 14a-g. The target compounds 15a-ae
The in vitro antifungal activity of target compounds was evalu-
ated against five pathogenic fungi according to the protocols of the
Clinical Laboratory Standard Institute (CLSI) [21]. Fluconazole (FCZ)
and itraconazole (ITZ) were used as reference drugs. The in vitro
results of the antifungal activities are summarized in Table 1.
The results showed that most of the compounds exhibited
moderate to good antifungal activities against Candida albicans,
Candida tropicalis, Candida glabrata, and Candida parapsilosis. Of
these, compounds 15a, 15b and 15u-ae show the excellent anti-
fungal activities with the MIC values in the range of 0.03e1 mg/mL,

L. Zhao et al. / European Journal of Medicinal Chemistry 183 (2019) 111689
3
Scheme 2. General synthesis of the target compounds 15a-ae. Reagents and conditions: (a) i) hexamethylenetetramine, CHCl3, 50 ꢀC; ii) 37% HCl, EtOH, reflux; (b) (Boc)2O, NaHCO3,
MeOH, H2O, rt.; (c) 37% CH2O (aq), NaHCO3, EtOH; (d) imidazole, CDI, CH3CN, 70 ꢀC; (e) HCleEtOH, rt.; (f) HOBt, EDCI, DIEA, DMF, rt.
Scheme 3. Synthesis of the target compound 18. Reagents and conditions: (a) Triazole, 1,10-Carbonyl-di(1,2,4-triazole), CH3CN, 70 ꢀC; (b) HCleEtOH, rt.; (c) HOBt, EDCI, DIEA, DMF,
rt.
which are superior to the reference drug fluconazole. The anti-
fungal activity of compound 15e with 40-F substituted on the
biphenyl group almost disappeared. Compounds 15f-n with -Cl or
eCH3 substituted on the biphenyl group was inactive against the
fungi. Compound 18 with a triazole group exhibited a slightly
decrease in antifungal activities against Candida albicans and
Candida tropicalis.
isolated from AIDS patients. Strains 632, 901 and 904 are also
fluconazole-resistant strains of Candida albicans, which were iso-
lated from clinic. The resistance mechanism of strain 17# is corre-
lated with the increase in mRNA levels of ERG11, CDR1 (encodes a
protein which belongs to the superfamily of ATP-binding cassette
transporters) and MDR1 (encodes a protein from the major facili-
tator superfamily). For the resistance strain CaR, increased MDR1
mRNA levels and the mutation of ERG11 (E266D, G464S, V488I)
correlated with decreased drug susceptibility. The potent com-
pounds were selected for evaluation of in vitro antifungal activity
against the five fluconazole-resistant strains. The results are sum-
marized in Table 2. The lead compound 5 was inactive against the
fluconazole-resistant strains 17# and CaR with the MIC
2.3. In vitro antifungal activity against fluconazole-resistant strains
of Candida albicans
In recent years, given the widespread use of antifungal agents,
fungi have developed severe resistance to marketed drugs, espe-
cially fluconazole. Therefore, it is necessary to evaluate its anti-
fungal activity against fluconazole-resistant strains in the
development of antifungal drugs. Strains 17# and CaR are
fluconazole-resistant strains of Candida albicans, which were
values > 64
m
g/mL. Compounds 15b, 15q, 15t and 15z with R1 ¼3-F
substituted and 15o and 15ae exhibited moderate antifungal ac-
tivities against strains 17# and CaR with MIC values in the range of
1e8 mg/mL. Among them, compounds 15z and 15ae exhibited the

4
L. Zhao et al. / European Journal of Medicinal Chemistry 183 (2019) 111689
Table 1
used to analyze the sterol composition in cells membrane using
fluconazole as the reference drug [22]. The sterol profile results
were summarized in Table 3. The sterol profile in the absence of
drug indicated that ergosterol was the only sterol (100%) detected.
In vitro antifungal activities of the target compounds (MIC, m
g/mL)a.
When Candida albicans were cultured with fluconazole at 0.25 mg/
mL, the content of ergosterol in the cell membrane decreased
sharply from 100% to 63%, and the contents of lanosterol, eburicol
and 14
lated. These changes in sterol levels were caused by inhibiting the
sterol 14 -demethylase enzyme (CYP51) of the ergosterol biosyn-
thetic pathway. When treated with compound 15ae at sub-MIC
levels of 0.015 g/mL, the same changing trend of sterol contents
a-methyl ergosta-8, 24(28)-dien-3b,6a-diol were accumu-
a
Compd. R1
R2
R3
C. alb.(I) C. alb.(II) C. tro. C. gla. C. par.
m
15a
15b
15c
15d
15e
15f
15g
15h
15i
2-F
3-F
H
H
H
2-Cl
3-Cl
H
H
H
20-F
30-F
40-F
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
2-F
2-F
2-F
3-F
3-F
3-F
3-Cl
3-Cl
3-Cl
4-F
4-F
4-F
4-Cl
4-Cl
4-Cl
0.06
0.125
0.5
0.25
4
>16
8
2
0.125
0.25
1
0.06
0.06
0.25
0.125 >64
8
>16
>16
>16
>16
>16
>16
>16
>16
>16
1
0.25
0.5
1
0.125
0.125
2
in the cell membrane was detected compared with the fluconazole
group. Moreover, we detected a relatively low amount of ergosterol
and a high quantity of lanosterol, eburicol and 14
8,24(28)-dien-3 ,6 -diol. The results indicated that compound
15ae acts by inhibiting the sterol 14 -demethylase enzyme
a-methyl ergosta-
0.5
1
b
a
>16
>16
>16
>16
>16
>16
>16
>16
>16
>16
0.125
0.5
>64
>64
>64
4
>64
>64
>64
>64
>64
>64
2
>64
>64
1
2
2
>64
>64
>64
>64
>64
>64
>64
>64
>64
>64
0.125
2
a
H
(CYP51), thereby affecting the biosynthesis of ergosterol.
20-Cl
40-Cl
H
H
0.5
2.5. In vitro cytotoxicity assay
15j
15k
15l
2-CH3
3-CH3
H
H
H
>16
>16
>16
>16
2
0.125
0.5
0.5
0.06
0.125
0.125
0.03
0.06
0.06
0.06
0.06
0.06
0.06
0.06
0.06
H
20-CH3
30-CH3
40-CH3
H
b
-Azole-phenylacetone derivatives exhibited excellent anti-
15m
15n
15o
15p
15q
15r
15s
15t
15u
15v
15w
15x
15y
15z
15aa
15 ab
15ac
15ad
15ae
18
fungal activity against pathogenic fungi. Therefore, it is necessary to
consider the potential toxicity to mammalian cells. Potent com-
pounds 15o, 15u, 15z and 15ae were selected to evaluate the
toxicity to human lung carcinoma A549 cells. The results are shown
in Table 4. In general, concentration-dependent toxicity against the
A549 cell line was observed for compounds 15u, 15z and 15ae.
H
2-F
3-F
H
2-F
3-F
H
2-F
3-F
H
2-F
3-F
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
4
1
0.25
1
0.5
0.03
1
1
0.5
1
0.5
0.125
0.25
0.5
When tested at the concentration of 10 mM/L, compounds 15o, 15u,
0.06
0.125
0.125
0.25
0.25
0.25
0.125
0.5
0.125 0.125
15z and 15ae were nontoxic, and cell survival was 100%, 96.35%,
86.78%, and 92.47%, respectively. Therefore, the compounds
showed no toxicity to A549 cells.
0.125 0.25
0.5
0.03
0.25
0.25
0.25
0.5
0.5
0.125
0.25
0.25
0.125 0.125 0.125
2.6. Structure-activity relationships
0.06
0.06
0.06
0.03
0.03
1
0.06
0.5
0.03
0.5
0.5
0.25
0.25
0.25
1
0.125
0.5
2-F
3-F
H
0.5
Compounds 15a and 15b with 2-F or 3-F substituted on the
biphenyl group maintain antifungal activity against the fungi with
the MIC values in the range of 0.06e0.5 mg/mL. The antifungal ac-
4-CH3 0.06
4-CH3 0.03
0.25
0.125
0.06
2
0.125
2
2-F
0.125 0.125
NDb
0.25
4
NDb
0.125
2
tivity decreased when the compounds with 20-F (15c) or 30-F (15d)
substituted on the biphenyl group. The antifungal activity of com-
pound 15e with 40-F on the biphenyl group disappeared. In addi-
tion, compounds 15f-n with -Cl or eCH3 substituted on the
biphenyl group were inactive against pathogenic fungi. This finding
may be due to the fact that the hydrophobic cavity of CYP51
occupied by biphenyl group is relatively narrow, and the -Cl and
eCH3 of large groups easily cause the collision with the CYP51
protein.
5
FCZ
ITZ
0.06
0.5
0.03
0.03
0.125 0.125
a
Abbreviations: C. alb.(I), Candida albicans (SC5314); C. alb.(II), Candida albicans
(GIM 2.194); C. tro., Candida tropicalis (GIM 2.183); C. gla., Candida glabrata; C. par.,
Candida parapsilosis (GIM 2.190); FCZ: Fluconazole; ITZ: Itraconazole.
b
ND ¼ not determined.
best antifungal activity against fluconazole-resistant strains with
Compounds 15o-t with R3 ¼ 2-F or 3-F exhibited slightly weaker
antifungal activity than compounds 15u-ae with R3 ¼ 3-Cl, 4-F, 4-Cl
or 4-CH3. When R3 is 3-Cl, 4-F, 4-Cl or 4-CH3 group, compounds
15u-ae exhibited similar activity, and the substitution on the
biphenyl group has minimal effect on the antifungal activity.
Replacing the imidazole group with a triazole, compound 18
showed slightly decreased activity.
MIC values in the range of 1e2
m
g/mL. Compounds with R1 ¼ H or
2-F substitution displayed moderate to good antifungal activity
against strains 632, 901 and 904, such as 15a, 15o, 15p. Of these,
compounds 15o, 15p, 15r and 15s with R3 ¼ 2-F or 3-F substitution
showed excellent antifungal activity against strains 632, 901 and
904 with MIC values in the range of 0.125e1 mg/mL. Compounds
15u, 15v, 15x, 15y and 15aa with R3 ¼ 3-Cl, 4-F or 4-Cl substitution
showed moderate antifungal activity. In addition, compound 15o
exhibited good antifungal activity against five fluconazole-resistant
strains.
For the resistant strains 17# and CaR, when R3 is an H or F atom,
only the compounds (15b, 15q, 15t, 15z) with R1 ¼3-F and 15o
exhibit the moderate antifungal activity. The compounds are
inactive when R3 is 3-Cl and 4-Cl. Moreover, when R3 is 4-CH3,
compound 15ae with R1 ¼ 2-F shows best antifungal activity
against the two resistant strains.
For the resistant strains 632, 901 and 904, compounds (such as
15o, 15p) with R1 ¼ H or 2-F substituted displayed moderate to
good antifungal activity. Of these, compounds with R3 ¼ 2-F or 3-F
substituted showed excellent antifungal activity against strains 632,
2.4. GC-MS analysis of sterol composition in Candida albicans
(SC5314)
b-Azole-phenylacetone derivatives are a novel class of anti-
fungal agents. To investigate the antifungal mechanism of com-
pound 15ae, gas chromatography-mass spectrometry (GC-MS) was
901 and 904 with MIC values in the range of 0.125e1 mg/mL.

L. Zhao et al. / European Journal of Medicinal Chemistry 183 (2019) 111689
5
Table 2
In vitro antifungal activities of the potent compounds (MIC,
m
g/mL)a.
Compd.
R1
R2
R3
Candida albicans
Strain 17#
Strain CaR
Strain 632
Strain 901
Strain 904
15a
15b
15o
15p
15q
15r
2-F
3-F
H
2-F
3-F
H
2-F
3-F
H
2-F
3-F
H
2-F
3-F
H
2-F
3-F
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
2-F
2-F
2-F
3-F
3-F
3-F
3-Cl
3-Cl
3-Cl
4-F
4-F
4-F
4-Cl
4-Cl
4-Cl
4-CH3
4-CH3
>64
2
8
>64
8
>64
>64
4
>64
>64
>64
>64
>64
2
>64
>64
>64
>64
2
>64
4
1
>64
4
>64
>64
2
>64
>64
>64
>64
>64
2
>64
>64
>64
>64
1
2
0.25
>64
0.25
0.25
>64
0.25
0.25
2
2
8
32
0.5
1
8
1
1
>64
4
4
>64
2
4
>64
4
>64
>64
>64
16
2
<0.125
0.25
2
0.5
0.5
32
4
4
>64
2
4
8
2
>64
32
32
16
1
15s
15t
15u
15v
15w
15x
15y
15z
15aa
15 ab
15ac
15ad
15ae
5
1
4
>64
1
>64
>64
2
>64
>64
16
2-F
16
>64
>64
0.25
>64
>64
0.25
0.5
>64
>64
FCZ
ITZ
>64
>64
>64
>64
aAbbreviations: strain 17#, fluconazole-resistant strain of Candida albicans; strain CaR, fluconazole-resistant strain of Candida albicans; strain 632, fluconazole-resistant strain
of Candida albicans; strain 901, fluconazole-resistant strain of Candida albicans; strain 904, fluconazole-resistant strain of Candida albicans; FCZ: Fluconazole; ITZ: Itraconazole.
Strains 17# and CaR were provided by Institute of Microbiology, Chinese Academy of Sciences. Strains 632, 901 and 904 were provided by the Second Military Medical
University.
Table 3
Table 4
Analysis of sterol composition in C. albicans by GC-MSa.
In vitro cytotoxicity of compounds in A549 cells.
Sterol
% of total sterols (C. alb.)
Compd.
Cell survival (mM/L)
No drug
FCZ
15ae
0.08
0.40
2
10
Lanosterol
Ergosterol
Eburicol
ND
100.00
ND
ND
ND
16.74
63.00
4.27
5.15
4.23
5.07
1.54
23.17
41.99
9.56
13.26
3.04
15o
15u
15z
15ae
FCZ
100%
100%
100%
100%
100%
100%
97.42%
100%
100%
99.07%
100%
97.23%
100%
96.96%
95.69%
100%
96.35%
86.78%
92.47%
95.34%
14
a
-methyl ergosta-8,24(28)-dien-3
b,6
a
-diol
Unknown sterol
Unknown sterol
Unknown sterol
ND
ND
5.85
3.13
a Abbreviations: The fungal strain was treated with DMSO (no drug), Fluconazole at
0.25 g/mL, Compound 15ae at 0.015
g/mL, ND ¼ Not detected.
m
m
imidazole group of compound 15z binds to the heme group through
formation of a coordination bond with the iron atom. The benzoyl
group forms hydrophobic interactions with Thr126, Ile131 and Tyr132
.
Compounds with R3 ¼ 3-Cl, 4-F or 4-Cl substituted showed mod-
The biphenyl group extends into the CYP51 channel and mainly
forms hydrophobic and Van der Waals interactions with the sur-
rounding residues, such as Leu121, Met508, Ser507, Pro230, Tyr64, and
Phe380. In addition, the 2-F on the biphenyl group can form halogen
(fluorine) bonds with Met508. The binding mode of compound 15o
with Candida albicans CYP51 is similar to that of 15z (Fig. 2B).
Amino acid mutations (Y132H, Y132F, K143R, G307S, and S405F)
in CYP51 from fluconazole-resistant Candida albicans that have not
been found in fluconazole-susceptible strains might potentially
influence fluconazole binding to CYP51. Of these, Y132 is the most
common resistance mutation site seen in fluconazole resistant
Candida albicans. The tertiary alcohol group of fluconazole interacts
with the residue Y132 through a water molecule by forming
erate antifungal activity.
2.7. Molecular docking model analysis of compounds 15o and 15z
in the active site of Candida albicans CYP51
To better understand the binding mode of compounds with
Candida albicans CYP51 and provide information for further opti-
mization, compounds 15o and 15z were docked into the active site
of Candida albicans CYP51 using the CDOCKER program in the
Discovery Studio 3.0 software. The published crystal structure of
Candida albicans CYP51 (PDB ID: 5V5Z) served as a useful template
for generating the binding mode [23]. As shown in Fig. 2A, the

6
L. Zhao et al. / European Journal of Medicinal Chemistry 183 (2019) 111689
Fig. 2. (A) Predicted binding mode of 15z in the active site of Candida albicans CYP51. (B) Predicted binding mode of 15o in the active site of Candida albicans CYP51. The halogen
bonds are shown as yellow dashed lines. Figures were generated using PyMOL. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web
version of this article.)
hydrogen bonds. However, when Y132 is mutated, the tertiary
4. Experimental section
alcohol group of fluconazole can be not interacted with the CYP51,
which reduces the binding force.
b
-Azole-phenylacetone de-
4.1. Chemistry
rivatives without the tertiary alcohol group might be advantage for
their antifungal activity against the fluconazole-resistance strains.
All reagents used in the experiment were procured from Aladdin,
Bide and Sinopharm Company (except special instruction) without
further purification. The key intermediates 8a-n and 12a-g were
synthesized according to the literature [19,24,25]. The solvents were
purified according to the standard procedures. The reactions were
monitored by TLC (Jiangyou, Yantai). TLC was performed on silica gel
plates with fluorescence F-254 and visualized with UV light. Silica
gel of 200e300 mesh (Jiangyou, Yantai) was used for column chro-
matography. The melting points of the compounds were determined
on a BüCHI Melting Point B-540 melting point apparatus and were
uncorrected. High-resolution mass spectra (HRMS) were performed
on an Agilent 6530 accurate-mass Q-TOF LC-MS system. GCꢁMS
analysis was performed on an Agilent 1200 LCꢁMS using ESI
mode. Nuclear magnetic resonance (NMR) spectra were recorded on
Bruker Avance III-600 or Bruker Avance III-400 instruments (600 or
400 MHz for 1H and 150 or 100 MHz for 13C) with TMS as an internal
standard. The coupling constants (J) are reported in Hertz, and the
peak multiplicities were described as s, singlet; d, doublet; t, triplet;
q, quartet; m, multiplet; and br, broad peak.
3. Conclusions
To combat the increasing incidence of susceptible fungal in-
fections and drug-resistant fungal infections, a number of azole
derivatives in our compound library were screened, and their
in vitro antifungal activity was evaluated. Compound 5 with a b-
azole-phenylacetone scaffold showed excellent antifungal activity
against the susceptible strains but was inactive against fluconazole-
resistant strains 17# and CaR. To discover compounds active against
both susceptible strains and fluconazole-resistant strains and to
explore the structure-activity relationship, a series of
b-azole-
phenylacetone derivatives with novel structure were designed and
synthesized. The synthesized compounds were evaluated for their
antifungal activity against five susceptible strains and five
fluconazole-resistant strains. Antifungal activity tests showed that
compounds 15a, 15b and 15u-ae exhibited excellent antifungal
activity against pathogenic strains with MIC values in the range of
0.03e1 mg/mL. In addition, compounds 15b, 15q, 15t and 15z with
R1 ¼3-F substituted and 15o and 15ae exhibited moderate anti-
4.2. General procedure for the synthesis of intermediates 8a-n
fungal activity against two fluconazole-resistant strains 17# and
Under an argon atmosphere, substituted 4-bromobenzoic acid
(1.1 equiv.), benzoic acid (1.0 equiv.), K2CO3 (2.0 equiv.), and Pd
[P(Ph)3]4 (0.1 equiv.) were added to dioxane/H2O (10:1). The mixture
was heated at 105 ꢀC for approximately 5 h. The reaction mixture
was cooled to room temperature, and the solvent was removed by
rotary evaporation. The residue was dissolved in water, and the
solution was acidified with 3 N HCl until the product precipitated.
The precipitate was filtered to afford compounds 8a-n.
CaR with MIC values in the range of 1e8 mg/mL. For the resistant
strains 632, 901 and 904, compounds with R1 ¼ H or 2-F substituted
displayed moderate to good antifungal activity. Of these, com-
pounds 15o, 15p, 15r and 15s showed excellent antifungal activity
against strains 632, 901 and 904 with MIC values in the range of
0.125e1 mg/mL. Compounds 15o and 15ae exhibited antifungal
activity against the five susceptible strains and five fluconazole-
resistant strains. Preliminary mechanistic studies showed that the
potent antifungal activity of compound 15ae stemmed from inhi-
bition of C. albicans CYP51. Compounds 15o, 15z and 15ae were
almost nontoxic to mammalian A549 cells. Further investigations of
the potent compounds 15o, 15z and 15ae are still in progress.
4.3. General procedure for the synthesis of intermediates 10a-g
Hexamethylenetetramine (1.0 equiv.) was added to a solution of

L. Zhao et al. / European Journal of Medicinal Chemistry 183 (2019) 111689
7
bromoacetophenone (1.0 equiv.) in CHCl3. The mixture was heated
4.8. The procedure for the synthesis of the compounds 15a-ae
at 50 ꢀC for approximately 2 h. After filtering, the residue was
washed with CHCl3 and EtOH sequentially. Then, the residue was
dissolved in EtOH, and 37% HCl (6.0 equiv.) was added to the
mixture. The mixture was refluxed for 4 h and monitored with TLC.
After filtering, the filtrate was evaporated in vacuum to afford
compounds 10a-g.
To a solution of acid 8a-n (1.0 equiv.) in DMF, HOBt (1.1 equiv.)
and EDCI (1.1 equiv.) were added and the mixture was stirred for
1 h at room temperature. Then the amino salt 14a-g (1.1 equiv.) and
DIEA (2.2 equiv.) were added. The reaction was stirred and moni-
tored with TLC. The mixture was poured into water and extracted
with ethylacetate three times. The combined organic layers were
dried over Na2SO4 and evaporated in a vacuum. The crude product
4.3.1. 2-Amino-1-phenylethan-1-one hydrochloride (10a)
Light white solid; yield: 89.5%. 1H NMR (600 MHz, DMSO)
d 8.40
was
purified
by
silica
gel
column
chromatography
(CH3OH:CH2Cl2 ¼ 40:1) to afford target compounds 15a-ae.
(s, 3H), 8.06e8.00 (m, 2H), 7.74 (t, J ¼ 7.4 Hz, 1H), 7.62e7.58 (m, 2H),
4.63e4.59 (m, 2H).
4.8.1. N-(3-(1H-imidazol-1-yl)-1-oxo-1-phenylpropan-2-yl)-2-
fluoro-[1,10-biphenyl]-4-carboxamide (15a)
4.4. The procedure for the synthesis of the intermediates 11a-g
Light white solid; yield: 48.5%; mp: 136.7e137.0 ꢀC. 1H NMR
(600 MHz, DMSO)
d
9.28 (d, J ¼ 8.4 Hz, 1H), 8.03 (d, J ¼ 7.5 Hz, 2H),
Briefly, (Boc)2O (1.5 equiv.) and NaHCO3 (2.5 equiv.) were added
to a solution of the amino 10a-g (1.0 equiv.) in MeOH/H2O (1:1). The
mixture was stirred at room temperature overnight, and then
poured into ice-water, and the product precipitated. The mixture
was filtered, and the residue was dried to give compounds 11a-g as
a white solid.
7.65 (ddd, J ¼ 21.9, 11.7, 7.1 Hz, 6H), 7.58e7.54 (m, 3H), 7.53 (t,
J ¼ 7.7 Hz, 2H), 7.50 (t, J ¼ 7.6 Hz, 2H), 7.44 (t, J ¼ 7.3 Hz, 1H), 7.25 (s,
1H), 6.86 (s, 1H), 5.81e5.77 (m, 1H), 4.61 (dd, J ¼ 14.1, 4.4 Hz, 1H),
4.43 (dd, J ¼ 14.1, 9.7 Hz, 1H). 13C NMR (150 MHz, DMSO)
d 197.28,
164.88, 159.95, 158.32, 138.41, 135.36, 134.76, 134.71, 134.62, 134.08,
131.93, 131.85, 131.44, 129.31, 129.18, 128.92, 128.78, 124.25, 120.53,
115.51, 115.35, 55.44, 46.27. HRMS (EI): m/z (Mþ) for C25H20FN3O2:
calcd. 413.154; found 413.1548.
4.5. The procedure for the synthesis of the intermediates 12a-g
To a solution of the amino protected compounds 11a-g (1.0
equiv.) in ethanol, NaHCO3 (0.5 M, 0.5 equiv.), 37% CH2O (1.5 equiv.)
were added. The mixture was stirred at 50 ꢀC for 48 h, and then the
organic solvent was removed under vacuum. The residue was dis-
solved in DCM and washed with water, brine sequentially. The
organic phase was dried over Na2SO4 and filtered. The filtrate was
concentrated and purified by silica column to give the compounds
12a-g as a white solid.
4.8.2. N-(3-(1H-imidazol-1-yl)-1-oxo-1-phenylpropan-2-yl)-3-
fluoro-[1,10-biphenyl]-4-carboxamide (15b)
Light white solid; yield: 43.1%; mp: 140.0e141.0 ꢀC. 1H NMR
(600 MHz, DMSO)
d
9.04 (dd, J ¼ 8.3, 1.4 Hz, 1H), 8.05e8.01 (m, 2H),
7.74e7.71 (m, 2H), 7.66 (t, J ¼ 6.8 Hz, 1H), 7.63 (s, 1H), 7.61e7.52 (m,
2H), 7.51e7.40 (m, 2H), 7.22 (s, 1H), 6.88 (s, 1H), 5.77e5.74 (m, 1H),
4.60 (dd, J ¼ 14.2, 4.4 Hz, 1H), 4.40 (dd, J ¼ 14.2, 9.4 Hz, 1H). 13C NMR
(150 MHz, DMSO)
d 197.16, 163.76, 160.85, 159.19, 145.29, 145.23,
4.5.1. .Tert-butyl (3-hydroxy-1-oxo-1-phenylpropan-2-yl)
138.40, 138.26, 135.31, 134.06, 130.86, 130.83, 129.56, 129.14, 128.84,
128.75, 127.41, 123.00, 121.99, 121.90, 120.51, 114.70, 114.54, 55.57,
46.31. HRMS (EI): m/z (Mþ) for C25H20FN3O2: calcd. 413.154; found
413.1548.
carbamate (12a)
Light white solid; yield: 70.6%. 1H NMR (600 MHz, CDCl3)
d 8.00
(d, J ¼ 7.5 Hz, 2H), 7.62 (t, J ¼ 7.4 Hz, 1H), 7.50 (t, J ¼ 7.8 Hz, 2H), 7.26
(s, 1H), 5.87 (s, 1H), 5.34 (s, 1H), 4.02 (dd, J ¼ 11.6, 3.4 Hz, 1H), 3.86
(dd, J ¼ 11.6, 4.6 Hz, 1H), 1.47 (s, 9H).
4.8.3. N-(3-(1H-imidazol-1-yl)-1-oxo-1-phenylpropan-2-yl)-20-
fluoro-[1,10-biphenyl]-4-carboxamide (15c)
Light white solid; yield: 47.8%. 1H NMR (600 MHz, DMSO)
d 9.41
4.6. The procedure for the synthesis of the intermediates 13a-g
(d, J ¼ 8.4 Hz, 1H), 8.05e8.02 (m, 2H), 7.86 (d, J ¼ 8.4 Hz, 2H), 7.68 (s,
1H), 7.64e7.59 (m, 3H), 7.56e7.50 (m, 3H), 7.47e7.44 (m, 1H),
7.35e7.30 (m, 2H), 7.26 (s, 1H), 6.84 (s, 1H), 5.78e5.72 (m, 1H), 4.60
(dd, J ¼ 14.1, 4.5 Hz, 1H), 4.49 (dd, J ¼ 14.1, 9.6 Hz, 1H). 13C NMR
The intermediates 12a-g (1.0 equiv.), CDI (1.2 equiv.), and
imidazole (1.0 equiv.) were added to acetonitrile. The mixture was
heated at 70 ꢀC for 2 h and then cooled to room temperature. The
solvent was removed under vacuum. The residue was dissolved in
ethylacetate, washed with water thrice, dried over Na2SO4 and
filtered. The filtrate was concentrated to afford compounds 13a-g as
a white solid.
(150 MHz, DMSO)
d 197.45, 166.08, 160.32, 158.68, 138.67, 138.39,
135.46, 133.95, 132.98, 131.26, 130.71, 130.66, 129.24, 129.22, 129.12
(2C), 128.78 (2C), 128.58, 128.13 (2C), 127.81, 125.54, 125.51, 120.58,
116.73, 116.59, 55.53, 46.23. HRMS (EI): m/z (Mþ) for C25H20FN3O2:
calcd. 413.154; found 413.1549.
4.6.1. Tert-butyl (3-(1H-imidazol-1-yl)-1-oxo-1-phenylpropan-2-
yl)carbamate (13a)
4.8.4. N-(3-(1H-imidazol-1-yl)-1-oxo-1-phenylpropan-2-yl)-30-
fluoro-[1,10-biphenyl]-4-carboxamide (15d)
Light white solid; yield: 78.3%. 1H NMR (600 MHz, DMSO)
d 7.96
Light white solid; yield: 45.5%; mp: 164.1e165.2 ꢀC. 1H NMR
(d, J ¼ 7.4 Hz, 2H), 7.65 (t, J ¼ 7.4 Hz, 1H), 7.59 (d, J ¼ 8.8 Hz, 1H), 7.57
(s, 1H), 7.52 (t, J ¼ 7.7 Hz, 2H), 7.17 (s, 1H), 6.85 (s, 1H), 5.30e5.26 (m,
1H), 4.43e4.39 (m, 1H), 4.18e4.14 (m, 1H), 1.26 (s, 9H).
(600 MHz, DMSO)
d
9.20 (t, J ¼ 7.5 Hz, 1H), 8.03 (d, J ¼ 6.9 Hz, 2H),
7.83e7.81 (m, 2H), 7.80e7.77 (m, 2H), 7.65e7.62 (m, 2H), 7.59e7.55
(m, 2H), 7.54e7.49 (m, 3H), 7.26e7.22 (m, 2H), 6.87e6.81 (m, 1H),
5.78e5.74 (m, 1H), 4.60 (dd, J ¼ 14.0, 3.9 Hz, 1H), 4.46e4.41 (m, 1H).
4.7. The procedure for the synthesis of the intermediates 14a-g
13C NMR (150 MHz, DMSO)
d 197.47, 166.06, 163.96, 162.34, 142.20,
The Boc protected compounds 13a-g (1.0 equiv.) was added to
HCleEtOH (4 N, 7.0 equiv.); then the mixture was stirred at room
temperature for 3 h. The mixture was filtered, and the residue was
dried to afford 14a-g as a white solid.
141.97, 141.92, 138.39, 135.43, 134.01, 133.10, 131.47, 131.42, 129.15
(2C), 128.78 (2C), 128.74, 128.44 (2C), 127.28 (2C), 123.46, 120.53,
115.39, 115.25, 114.19, 114.05, 55.43, 46.28. HRMS (EI): m/z (Mþ) for
C25H20FN3O2: calcd. 413.154; found 413.1548.

8
L. Zhao et al. / European Journal of Medicinal Chemistry 183 (2019) 111689
4.8.5. N-(3-(1H-imidazol-1-yl)-1-oxo-1-phenylpropan-2-yl)-40-
fluoro-[1,10-biphenyl]-4-carboxamide (15e)
4.8.10. N-(3-(1H-imidazol-1-yl)-1-oxo-1-phenylpropan-2-yl)-2-
methyl-[1,10-biphenyl]-4-carboxamide (15j)
Light white solid; yield: 47.1%; mp: 110.0e110.9 ꢀC. 1H NMR
Light white solid; yield: 49.5%; mp: 83.4e85.2 ꢀC. 1H NMR
(600 MHz, DMSO)
d
9.18 (d, J ¼ 8.3 Hz, 1H), 8.03 (d, J ¼ 7.9 Hz, 2H),
(600 MHz, DMSO) d 9.18 (s,1H), 8.02 (d, 2H), 7.68e7.60 (m, 4H), 7.52
7.80 (d, J ¼ 8.3 Hz, 2H), 7.76e7.73 (m, 2H), 7.72 (d, J ¼ 8.4 Hz, 2H),
7.65e7.61 (m, 2H), 7.52 (t, J ¼ 7.8 Hz, 2H), 7.31 (t, J ¼ 8.9 Hz, 2H), 7.23
(s, 1H), 6.85 (s, 1H), 5.76 (td, J ¼ 9.0, 4.6 Hz, 1H), 4.60 (dd, J ¼ 14.1,
4.4 Hz, 1H), 4.43 (dd, J ¼ 14.1, 9.7 Hz, 1H). 13C NMR (150 MHz,
(t, J ¼ 7.8 Hz, 2H), 7.45 (t, J ¼ 7.5 Hz, 2H), 7.38 (t, J ¼ 6.8 Hz, 1H),
7.34e7.32 (m, 2H), 7.27e7.22 (m, 2H), 6.86 (s, 1H), 5.76 (td, J ¼ 9.1,
4.5 Hz, 1H), 4.60 (dd, J ¼ 14.1, 4.5 Hz, 1H), 4.46e4.41 (m, 1H), 2.23 (s,
3H). 13C NMR (150 MHz, DMSO)
d 197.47, 166.19, 144.97, 140.82,
DMSO)
d
197.48, 166.12, 163.54, 161.91, 142.63, 138.38, 136.01,
138.36, 135.44, 133.98, 132.53, 130.05, 129.74, 129.23 (2C), 129.13
(2C), 128.79 (4C), 128.59, 127.84, 125.34, 120.58, 55.28, 46.36, 20.64.
HRMS (EI): m/z (Mþ) for C26H23N3O2: calcd. 409.179; found
409.1791.
135.99, 135.44, 134.00, 132.51, 129.47, 129.42, 129.14 (2C), 128.78
(2C), 128.73, 128.43 (2C), 127.04 (2C), 120.52, 116.39, 116.25, 55.41,
46.28. HRMS (EI): m/z (Mþ) for C25H20FN3O2: calcd. 413.154; found
413.1539.
4.8.11. N-(3-(1H-imidazol-1-yl)-1-oxo-1-phenylpropan-2-yl)-3-
methyl-[1,10-biphenyl]-4-carboxamide (15k)
4.8.6. N-(3-(1H-imidazol-1-yl)-1-oxo-1-phenylpropan-2-yl)-2-
chloro-[1,10-biphenyl]-4-carboxamide (15f)
Light white solid; yield: 48.8%; mp: 147.9e149.6 ꢀC. 1H NMR
Light white solid; yield: 48.5%; mp: 151.1e153.0 ꢀC. 1H NMR
(600 MHz, DMSO)
d
8.99 (d, J ¼ 8.6 Hz, 1H), 8.02 (d, J ¼ 7.4 Hz, 2H),
(600 MHz, DMSO)
d
9.31 (d, J ¼ 8.4 Hz, 1H), 8.03e8.00 (m, 2H), 7.89
7.67 (t, J ¼ 7.4 Hz, 2H), 7.63 (d, J ¼ 7.4 Hz, 2H), 7.55 (t, J ¼ 7.8 Hz, 2H),
7.47e7.43 (m, 4H), 7.37 (t, J ¼ 7.3 Hz, 1H), 7.27 (s, 1H), 7.08e7.05 (m,
1H), 6.91 (s, 1H), 5.77e5.73 (m, 1H), 4.57 (dd, J ¼ 14.1, 4.3 Hz, 1H),
4.38 (dd, J ¼ 14.1, 10.0 Hz, 1H), 2.06 (s, 3H). 13C NMR (150 MHz,
(d, J ¼ 1.1 Hz, 1H), 7.76 (d, J ¼ 8.0 Hz, 1H), 7.65e7.62 (m, 2H), 7.53 (t,
J ¼ 7.7 Hz, 2H), 7.50e7.46 (m, 3H), 7.45e7.42 (m, 3H), 7.23 (s, 1H),
6.85 (s, 1H), 5.79e5.76 (m, 1H), 4.59 (dd, J ¼ 14.2, 4.4 Hz, 1H), 4.42
(dd, J ¼ 14.1, 9.7 Hz, 1H). 13C NMR (150 MHz, DMSO)
d
197.26,
DMSO) d 197.62, 168.95, 141.83, 139.80, 138.49, 136.75, 135.56,
164.80, 143.28, 138.41, 138.32, 135.36, 134.25, 134.08, 132.14, 131.93,
129.54, 129.19, 128.95, 128.78, 128.69, 126.82, 120.54, 55.41, 46.27.
HRMS (EI): m/z (Mþ) for C25H20ClN3O2: calcd. 429.1244; found
429.1238.
135.06, 133.95, 129.41 (2C), 129.26, 129.08 (2C), 128.79 (3C), 128.29,
127.98, 127.22 (2C), 124.17, 120.59, 55.03, 46.28, 19.50. HRMS (EI):
m/z (Mþ) for C26H23N3O2: calcd. 409.179; found 409.1803.
4.8.12. N-(3-(1H-imidazol-1-yl)-1-oxo-1-phenylpropan-2-yl)-20-
methyl-[1,10-biphenyl]-4-carboxamide (15l)
4.8.7. N-(3-(1H-imidazol-1-yl)-1-oxo-1-phenylpropan-2-yl)-3-
chloro-[1,10-biphenyl]-4-carboxamide (15g)
Light white solid; yield: 46.5%; mp: 143.4e144.2 ꢀC. 1H NMR
Light white solid; yield: 49.0%; mp: 141.5e142.8 ꢀC. 1H NMR
(600 MHz, DMSO)
d
9.18 (d, J ¼ 8.4 Hz, 1H), 8.03 (d, J ¼ 7.8 Hz, 2H),
(600 MHz, DMSO)
d
9.21 (d, J ¼ 8.6 Hz, 1H), 8.03 (d, J ¼ 7.9 Hz, 2H),
7.77 (d, J ¼ 8.1 Hz, 2H), 7.67e7.62 (m, 2H), 7.53 (t, J ¼ 7.7 Hz, 2H),
7.40 (d, J ¼ 8.2 Hz, 2H), 7.30e7.24 (m, 4H), 7.18 (d, J ¼ 7.2 Hz, 1H),
6.86 (s, 1H), 5.79e5.75 (m, 1H), 4.59 (dd, J ¼ 14.1, 4.3 Hz, 1H), 4.43
(dd, J ¼ 14.1, 9.7 Hz, 1H), 2.20 (s, 3H). 13C NMR (150 MHz, DMSO)
7.71e7.64 (m, 6H), 7.56 (t, J ¼ 7.7 Hz, 2H), 7.47 (t, J ¼ 7.6 Hz, 2H), 7.41
(t, J ¼ 7.2 Hz, 1H), 7.27 (s, 1H), 7.12 (d, J ¼ 8.0 Hz, 1H), 6.91 (s, 1H),
5.77 (td, J ¼ 9.1, 4.4 Hz, 1H), 4.57 (dd, J ¼ 14.1, 4.4 Hz, 1H), 4.37 (dd,
J ¼ 14.1, 9.7 Hz, 1H). 13C NMR (150 MHz, DMSO)
d
197.16, 166.29,
d 197.45, 166.33, 145.05, 140.79, 138.40, 135.44, 135.13, 134.02,
143.43, 138.54, 138.29, 135.36, 134.75, 134.06, 131.12, 129.56 (3C),
129.11 (2C), 128.95 (2C), 128.82, 128.03, 127.38 (3C), 125.69, 120.58,
55.02, 46.26. HRMS (EI): m/z (Mþ) for C25H20ClN3O2: calcd.
429.1244; found 429.1249.
132.31, 130.91, 129.87, 129.48, 129.17, 128.80, 128.76, 128.23, 127.72,
126.50, 120.53, 55.37, 46.29, 20.58. HRMS (EI): m/z (Mþ) for
C26H23N3O2: calcd. 409.179; found 409.1805.
4.8.13. N-(3-(1H-imidazol-1-yl)-1-oxo-1-phenylpropan-2-yl)-30-
methyl-[1,10-biphenyl]-4-carboxamide (15m)
4.8.8. N-(3-(1H-imidazol-1-yl)-1-oxo-1-phenylpropan-2-yl)-20-
chloro-[1,10-biphenyl]-4-carboxamide (15h)
Light white solid; yield: 53.7%; mp: 150.6e152.1 ꢀC. 1H NMR
Light white solid; yield: 54.8%; mp: 115.4e117.1 ꢀC. 1H NMR
(600 MHz, DMSO)
d
9.17 (d, J ¼ 8.4 Hz, 1H), 8.05e8.01 (m, 2H), 7.80
(600 MHz, DMSO)
d
9.21 (d, J ¼ 8.4 Hz, 1H), 8.05e8.00 (m, 2H), 7.79
(d, J ¼ 8.4 Hz, 2H), 7.71 (d, J ¼ 8.4 Hz, 2H), 7.67 (s, 1H), 7.63 (t,
J ¼ 7.4 Hz, 1H), 7.54e7.50 (m, 3H), 7.48 (d, J ¼ 7.8 Hz, 1H), 7.36 (t,
J ¼ 7.6 Hz, 1H), 7.24 (s, 1H), 7.21 (d, J ¼ 7.3 Hz, 1H), 6.86 (s, 1H),
5.78e5.74 (m, 1H), 4.60 (dd, J ¼ 14.1, 4.5 Hz, 1H), 4.43 (dd, J ¼ 14.1,
(d, J ¼ 8.4 Hz, 2H), 7.66e7.61 (m, 2H), 7.59e7.56 (m, 1H), 7.53 (t,
J ¼ 7.8 Hz, 2H), 7.49 (d, J ¼ 8.4 Hz, 2H), 7.45e7.39 (m, 3H), 7.24 (s,
1H), 6.85 (s, 1H), 5.78e5.75 (m, 1H), 4.60 (dd, J ¼ 14.1, 4.5 Hz, 1H),
4.43 (dd, J ¼ 14.1, 9.7 Hz, 1H). 13C NMR (150 MHz, DMSO)
d
197.42,
9.6 Hz, 1H), 2.37 (s, 3H). 13C NMR (150 MHz, DMSO)
d 197.47, 166.18,
166.19, 142.33, 139.38, 138.40, 135.42, 134.03, 133.06, 131.87, 131.63,
130.36, 130.14, 129.78, 129.16, 128.78, 128.74, 128.07, 127.68, 120.55,
55.40, 46.29. HRMS (EI): m/z (Mþ) for C25H20ClN3O2: calcd.
429.1244; found 429.1254.
143.81, 139.48, 138.68,138.34, 135.44, 134.01, 132.45, 129.38, 129.23,
129.15 (2C), 128.78 (2C), 128.55, 128.38 (2C), 127.96, 127.04 (2C),
124.48, 120.59, 55.37, 46.35, 21.54. HRMS (EI): m/z (Mþ) for
C26H23N3O2: calcd. 409.179; found 409.1789.
4.8.9. N-(3-(1H-imidazol-1-yl)-1-oxo-1-phenylpropan-2-yl)-40-
chloro-[1,10-biphenyl]-4-carboxamide (15i)
4.8.14. N-(3-(1H-imidazol-1-yl)-1-oxo-1-phenylpropan-2-yl)-40-
methyl-[1,10-biphenyl]-4-carboxamide (15n)
Light white solid; yield: 52.6%; mp: 176.5e177.7 ꢀC. 1H NMR
Light white solid; yield: 46.3%; mp: 129.9e132.5 ꢀC. 1H NMR
(600 MHz, DMSO)
d
9.19 (d, J ¼ 8.4 Hz, 1H), 8.02 (d, J ¼ 7.3 Hz, 2H),
(600 MHz, DMSO)
d
9.17 (d, J ¼ 8.4 Hz, 1H), 8.04e8.00 (m, 2H), 7.79
7.81 (d, J ¼ 8.4 Hz, 2H), 7.76e7.71 (m, 4H), 7.66 (s, 1H), 7.63 (t,
J ¼ 7.4 Hz, 1H), 7.55e7.49 (m, 4H), 7.23 (s, 1H), 6.85 (s, 1H), 5.76 (td,
J ¼ 9.2, 4.6 Hz, 1H), 4.60 (dd, J ¼ 14.1, 4.5 Hz, 1H), 4.42 (dd, J ¼ 14.1,
(d, J ¼ 8.4 Hz, 2H), 7.74e7.68 (m, 3H), 7.63 (t, J ¼ 7.4 Hz, 1H), 7.59 (d,
J ¼ 8.1 Hz, 2H), 7.52 (t, J ¼ 7.8 Hz, 2H), 7.28 (d, J ¼ 8.0 Hz, 2H), 7.26 (s,
1H), 6.89 (s,1H), 5.76 (td, J ¼ 9.3, 4.5 Hz,1H), 4.61 (dd, J ¼ 14.1, 4.5 Hz,
1H), 4.43 (dd, J ¼ 14.1, 9.6 Hz, 1H), 2.34 (s, 3H). 13C NMR (150 MHz,
9.6 Hz, 1H). 13C NMR (150 MHz, DMSO)
d 197.47, 166.07, 142.31,
138.38, 138.33, 135.43, 134.01, 133.53, 132.85, 129.45 (2C), 129.16
(4C), 128.78 (2C), 128.73, 128.48 (2C), 127.08 (2C), 120.52, 55.41,
46.28. HRMS (EI): m/z (Mþ) for C25H20ClN3O2: calcd. 429.1244;
found 429.1250.
DMSO) d 197.49, 166.18, 143.61, 138.37, 138.07, 136.61, 135.44, 134.00,
132.23, 130.09 (2C), 129.14 (2C), 128.78 (2C), 128.67, 128.40 (2C),
127.18 (2C), 126.75 (2C), 120.55, 55.39, 46.31, 21.17. HRMS (EI): m/z
(Mþ) for C26H23N3O2: calcd. 409.179; found 409.1797.

L. Zhao et al. / European Journal of Medicinal Chemistry 183 (2019) 111689
9
4.8.15. N-(1-(2-fluorophenyl)-3-(1H-imidazol-1-yl)-1-oxopropan-
2-yl)-[1,10-biphenyl]-4-carboxamide (15o)
d 196.32, 164.97, 163.26, 161.63, 159.96, 158.32, 138.40, 137.63,
137.59, 134.59, 134.54, 132.02, 131.93, 131.51, 131.49, 131.42, 131.37,
129.32, 129.30, 129.18 (2C), 128.94, 128.71, 124.93, 124.23, 124.21,
121.02, 120.87, 120.56, 115.50, 115.34, 115.31, 115.15, 55.62, 46.12.
HRMS (EI): m/z (Mþ) for C25H19F2N3O2: calcd. 431.1445; found
431.1449.
Light white solid; yield: 44.8%; mp: 176.7e178.3 ꢀC. 1H NMR
(600 MHz, DMSO)
d
9.25 (d, J ¼ 7.7 Hz, 1H), 7.79 (td, J ¼ 7.6, 1.6 Hz,
1H), 7.76 (d, J ¼ 8.5 Hz, 2H), 7.72 (d, J ¼ 8.5 Hz, 2H), 7.70e7.68 (m,
2H), 7.60 (s, 2H), 7.48 (t, J ¼ 7.7 Hz, 2H), 7.40 (t, J ¼ 7.4 Hz, 1H),
7.34e7.29 (m, 2H), 7.18 (s, 1H), 6.86 (s, 1H), 5.35 (td, J ¼ 9.2, 4.2 Hz,
1H), 4.67 (dd, J ¼ 14.2, 4.2 Hz, 1H), 4.42 (dd, J ¼ 14.2, 9.5 Hz, 1H). 13
C
4.8.20. 3-Fluoro-N-(1-(3-fluorophenyl)-3-(1H-imidazol-1-yl)-1-
oxopropan-2-yl)-[1,10-biphenyl]-4-carboxamide (15t)
NMR (150 MHz, DMSO)
d 195.95, 166.10, 161.05, 159.37, 143.26,
139.07, 137.84, 134.82, 134.76, 131.97, 130.62, 129.03 (2C), 128.37,
128.14, 127.91 (2C), 126.91 (2C), 126.63 (2C), 124.56, 124.46, 124.38,
119.96, 116.60, 116.45, 58.88, 58.86, 45.19. HRMS (EI): m/z (Mþ) for
Light white solid; yield: 38.9%; mp: 142.2e144.1 ꢀC. 1H NMR
(600 MHz, DMSO)
d
9.08 (d, J ¼ 6.9 Hz, 1H), 7.85 (d, J ¼ 7.8 Hz, 1H),
7.78e7.75 (m, 1H), 7.72 (d, J ¼ 7.3 Hz, 2H), 7.65 (s, 1H), 7.61e7.56 (m,
3H), 7.54e7.50 (m, 1H), 7.49 (t, J ¼ 7.6 Hz, 2H), 7.46e7.41 (m, 2H),
7.23 (s, 1H), 6.89 (s, 1H), 5.70 (td, J ¼ 9.0, 4.5 Hz, 1H), 4.60 (dd,
J ¼ 14.2, 4.4 Hz, 1H), 4.42 (dd, J ¼ 14.2, 9.4 Hz, 1H). 13C NMR
C
25H20FN3O2: calcd. 413.154; found 413.1552.
4.8.16. 2-Fluoro-N-(1-(2-fluorophenyl)-3-(1H-imidazol-1-yl)-1-
oxopropan-2-yl)-[1,10-biphenyl]-4-carboxamide (15p)
(150 MHz, DMSO)
d 196.23, 163.85, 163.24, 161.61, 160.84, 159.18,
Light white solid; yield: 49.5%; mp: 163.0e163.9 ꢀC. 1H NMR
145.37, 145.31, 138.40, 138.23, 137.60, 137.56, 131.35, 131.30, 130.80,
130.79, 129.56 (2C), 129.15, 128.63, 127.41 (2C), 124.96, 124.94,
123.07, 123.05, 121.82, 121.73, 120.94, 120.80, 120.56, 115.39, 115.24,
114.73, 114.57, 55.82, 46.13. HRMS (EI): m/z (Mþ) for C25H19F2N3O2:
calcd. 431.1445; found 431.1456.
(600 MHz, DMSO)
d
9.34 (d, J ¼ 7.7 Hz, 1H), 7.81e7.78 (m, 1H),
7.64e7.58 (m, 5H), 7.56 (d, J ¼ 8.5 Hz, 2H), 7.49 (t, J ¼ 7.5 Hz, 2H),
7.44 (t, J ¼ 7.3 Hz, 1H), 7.34e7.30 (m, 2H), 7.18 (s, 1H), 6.87 (s, 1H),
5.39e5.35 (m, 1H), 4.67 (dd, J ¼ 14.2, 4.2 Hz, 1H), 4.41 (dd, J ¼ 14.2,
9.5 Hz, 1H). 13C NMR (150 MHz, DMSO)
d 196.15, 165.27, 161.53,
159.89 (d, J ¼ 10.7 Hz), 158.28, 138.32, 135.39, 135.34, 134.64, 134.61,
131.96, 131.87, 131.47, 131.44, 131.09, 129.31, 129.30, 129.22, 129.17
(2C), 128.90, 125.08, 124.81, 124.73, 124.20, 124.18, 120.41, 117.10,
116.95, 115.45, 115.29, 59.39, 59.37e59.35 (m), 45.62. HRMS (EI): m/
z (Mþ) for C25H19F2N3O2: calcd. 431.1445; found 431.1457.
4.8.21. N-(1-(3-chlorophenyl)-3-(1H-imidazol-1-yl)-1-oxopropan-
2-yl)-[1,10-biphenyl]-4-carboxamide (15u)
Light white solid; yield: 52.5%; mp: 126.6e127.8 ꢀC. 1H NMR
(600 MHz, DMSO)
d
9.22 (d, J ¼ 8.2 Hz, 1H), 7.99 (t, J ¼ 1.8 Hz, 1H),
7.94 (d, J ¼ 7.9 Hz,1H), 7.79 (d, J ¼ 8.5 Hz, 2H), 7.74 (d, J ¼ 8.5 Hz, 2H),
7.71e7.68 (m, 3H), 7.62 (s, 1H), 7.55 (t, J ¼ 7.9 Hz, 1H), 7.48 (t,
J ¼ 7.7 Hz, 2H), 7.40 (t, J ¼ 7.4 Hz, 1H), 7.21 (s, 1H), 6.84 (s, 1H), 5.69
(td, J ¼ 8.9, 4.6 Hz, 1H), 4.59 (dd, J ¼ 14.1, 4.5 Hz, 1H), 4.43 (dd,
4.8.17. 3-Fluoro-N-(1-(2-fluorophenyl)-3-(1H-imidazol-1-yl)-1-
oxopropan-2-yl)-[1,10-biphenyl]-4-carboxamide (15q)
Light white solid; yield: 45.6%; mp: 126.3e128.2 ꢀC. 1H NMR
(400 MHz, DMSO)
d
10.13 (d, J ¼ 5.6 Hz, 1H), 9.14e9.06 (m, 1H),
J ¼ 14.1, 9.5 Hz, 1H). 13C NMR (150 MHz, DMSO)
d 196.62, 166.27,
7.83e7.76 (m, 2H), 7.73e7.70 (m, 2H), 7.65e7.63 (m, 1H), 7.60 (s,
1H), 7.59e7.54 (m, 2H), 7.50e7.46 (m, 2H), 7.44e7.39 (m, 2H),
7.35e7.31 (m, 2H), 7.18 (s, 1H), 6.89 (s, 1H), 5.37 (td, J ¼ 8.6, 4.3 Hz,
143.79, 139.50, 138.38, 137.41, 133.93, 133.57, 132.40, 131.09, 129.49
(2C), 128.74, 128.62, 128.39 (3C), 127.37 (2C), 127.30, 127.14 (2C),
120.53, 55.61, 46.09. HRMS (EI): m/z (Mþ) for C25H20ClN3O2: calcd.
429.1244; found 429.1256.
1H), 4.67 (dd, J ¼ 14.2, 4.3 Hz, 1H), 4.41 (dd, J ¼ 14.2, 9.1 Hz, 1H). 13
C
NMR (150 MHz, DMSO)
d 195.63, 163.64, 161.11, 160.34, 159.43,
158.68, 144.80,144.75,140.90,137.79,134.90,134.84,130.63,130.29,
130.27, 129.09 (2C), 128.66, 128.38, 126.95 (2C), 124.58, 124.34,
124.26, 122.53, 122.51, 121.44, 121.34, 119.96, 116.61, 116.46, 114.22,
114.06, 58.93, 45.18. HRMS (EI): m/z (Mþ) for C25H19F2N3O2: calcd.
431.1445; found 431.1453.
4.8.22. N-(1-(3-chlorophenyl)-3-(1H-imidazol-1-yl)-1-oxopropan-
2-yl)-2-fluoro-[1,10-biphenyl]-4-carboxamide (15v)
Light white solid; yield: 47.9%; mp: 81.3e83.1 ꢀC. 1H NMR
(600 MHz, DMSO)
d
9.31 (d, J ¼ 8.2 Hz, 1H), 7.98 (t, J ¼ 1.8 Hz, 1H),
7.95e7.91 (m, 1H), 7.71e7.69 (m, 1H), 7.67e7.60 (m, 4H), 7.58e7.54
(m, 3H), 7.52e7.48 (m, 2H), 7.46e7.42 (m, 1H), 7.23 (s, 1H), 6.87 (s,
1H), 5.72 (td, J ¼ 9.3, 4.6 Hz, 1H), 4.60 (dd, J ¼ 14.1, 4.5 Hz, 1H), 4.43
4.8.18. N-(1-(3-fluorophenyl)-3-(1H-imidazol-1-yl)-1-oxopropan-
2-yl)-[1,10-biphenyl]-4-carboxamide (15r)
(dd, J ¼ 14.1, 9.5 Hz, 1H). 13C NMR (150 MHz, DMSO)
d 195.95,
Light white solid; yield: 50.7%; mp: 145.2e146.7 ꢀC. 1H NMR
164.53, 159.50, 157.86, 137.95, 136.87, 134.14, 134.13, 134.10, 133.52,
133.17, 131.56, 131.47, 131.03, 131.01, 130.65, 128.84, 128.82, 128.69
(2C), 128.45, 128.35, 127.93, 126.84, 123.75, 123.73, 120.06, 115.03,
114.87, 55.17, 45.61. HRMS (EI): m/z (Mþ) for C25H19ClFN3O2: calcd.
447.115; found 447.1171.
(600 MHz, DMSO)
d
9.21 (d, J ¼ 8.3 Hz, 1H), 7.86 (d, J ¼ 7.8 Hz, 1H),
7.80 (d, J ¼ 8.5 Hz, 2H), 7.78e7.75 (m, 1H), 7.74 (d, J ¼ 8.5 Hz, 2H),
7.71e7.68 (m, 2H), 7.62 (s, 1H), 7.58 (td, J ¼ 8.0, 5.8 Hz, 1H), 7.49 (dt,
J ¼ 11.1, 6.1 Hz, 3H), 7.40 (t, J ¼ 7.4 Hz, 1H), 7.22 (s, 1H), 6.84 (s, 1H),
5.72e5.69 (m, 1H), 4.60 (dd, J ¼ 14.1, 4.5 Hz, 1H), 4.44 (dd, J ¼ 14.1,
9.6 Hz, 1H). 13C NMR (150 MHz, DMSO)
d 196.54, 166.26, 163.24,
161.62, 143.79, 139.51, 138.38, 137.73, 137.69, 132.40, 131.37, 131.32,
129.50 (2C), 128.73, 128.62, 128.41 (2C), 127.37 (2C), 127.14 (2C),
124.92, 120.92, 120.78, 120.54, 115.31, 115.16, 55.61, 46.13. HRMS
(EI): m/z (Mþ) for C25H20FN3O2: calcd. 413.154; found 413.155.
4.8.23. N-(1-(3-chlorophenyl)-3-(1H-imidazol-1-yl)-1-oxopropan-
2-yl)-3-fluoro-[1,10-biphenyl]-4-carboxamide (15w)
Light white solid; yield: 47.2%; mp: 126.0e128.0 ꢀC. 1H NMR
(600 MHz, DMSO)
d
9.09 (dd, J ¼ 8.2, 1.3 Hz, 1H), 7.99 (t, J ¼ 1.8 Hz,
1H), 7.94 (d, J ¼ 7.9 Hz, 1H), 7.73e7.71 (m, 3H), 7.64 (s, 1H),
7.60e7.55 (m, 3H), 7.49 (t, J ¼ 7.6 Hz, 2H), 7.46e7.41 (m, 2H), 7.22 (s,
1H), 6.89 (s, 1H), 5.69 (td, J ¼ 8.9, 4.5 Hz, 1H), 4.60 (dd, J ¼ 14.2,
4.5 Hz, 1H), 4.41 (dd, J ¼ 14.2, 9.3 Hz, 1H). 13C NMR (150 MHz,
4.8.19. 2-Fluoro-N-(1-(3-fluorophenyl)-3-(1H-imidazol-1-yl)-1-
oxopropan-2-yl)-[1,10-biphenyl]-4-carboxamide (15s)
Light white solid; yield: 54.8%; mp: 128.2e130.8 ꢀC. 1H NMR
(600 MHz, DMSO)
d
9.30 (d, J ¼ 8.3 Hz, 1H), 7.85 (d, J ¼ 7.8 Hz, 1H),
DMSO) d 196.32, 163.83, 160.83, 159.17, 145.38, 145.33, 138.39,
7.78e7.75 (m, 1H), 7.67e7.61 (m, 4H), 7.59e7.54 (m, 3H), 7.50 (t,
J ¼ 7.6 Hz, 3H), 7.46e7.42 (m, 1H), 7.22 (t, J ¼ 1.1 Hz, 1H), 6.85 (d,
J ¼ 0.9 Hz, 1H), 5.73 (td, J ¼ 9.4, 4.6 Hz, 1H), 4.60 (dd, J ¼ 14.2, 4.5 Hz,
1H), 4.43 (dd, J ¼ 14.2, 9.6 Hz, 1H). 13C NMR (150 MHz, DMSO)
138.22, 137.30, 133.93, 133.59, 131.07, 130.79, 130.77, 129.56 (2C),
129.15, 128.69, 128.44, 127.42 (2C), 127.34, 123.07, 123.05, 121.80,
121.70, 120.54, 114.73, 114.57, 55.80, 46.08. HRMS (EI): m/z (Mþ) for
C25H19ClFN3O2: calcd. 447.115; found 447.1162.

10
L. Zhao et al. / European Journal of Medicinal Chemistry 183 (2019) 111689
4.8.24. N-(1-(4-fluorophenyl)-3-(1H-imidazol-1-yl)-1-oxopropan-
2-yl)-[1,10-biphenyl]-4-carboxamide (15x)
4.8.29. N-(1-(4-chlorophenyl)-3-(1H-imidazol-1-yl)-1-oxopropan-
2-yl)-3-fluoro-[1,10-biphenyl]-4-carboxamide (15ac)
Light white solid; yield: 50.6%; mp: 81.7e83.5 ꢀC. 1H NMR
Light white solid; yield: 40.5%; mp: 120.2e122.1 ꢀC. 1H NMR
(600 MHz, DMSO)
d
9.18 (d, J ¼ 8.3 Hz, 1H), 8.10 (dd, J ¼ 8.8, 5.5 Hz,
(600 MHz, DMSO)
d
9.06 (dd, J ¼ 8.2, 1.5 Hz, 1H), 8.02 (d, J ¼ 8.6 Hz,
2H), 7.81 (d, J ¼ 8.4 Hz, 2H), 7.74 (d, J ¼ 8.4 Hz, 2H), 7.71e7.68 (m,
2H), 7.63 (s, 1H), 7.48 (t, J ¼ 7.6 Hz, 2H), 7.40 (t, J ¼ 7.3 Hz, 1H), 7.36 (t,
J ¼ 8.8 Hz, 2H), 7.22 (s, 1H), 6.84 (s, 1H), 5.76e5.72 (m, 1H), 4.58 (dd,
J ¼ 14.1, 4.6 Hz,1H), 4.43 (dd, J ¼ 14.1, 9.6 Hz,1H). 13C NMR (150 MHz,
2H), 7.73 (d, J ¼ 7.3 Hz, 2H), 7.63e7.61 (m, 4H), 7.59e7.56 (m, 1H),
7.51e7.45 (m, 4H), 7.43 (t, J ¼ 7.3 Hz,1H), 7.21 (s,1H), 6.88 (s,1H), 5.71
(td, J ¼ 8.9, 4.5 Hz, 1H), 4.59 (dd, J ¼ 14.2, 4.5 Hz, 1H), 4.41 (dd,
J ¼ 14.2, 9.3 Hz, 1H). 13C NMR (150 MHz, DMSO)
d 196.30, 163.79,
DMSO)
d
195.65, 165.96, 165.73, 164.28, 143.27, 139.05, 137.90,
160.84, 159.18, 145.36, 145.30, 138.86, 138.40, 138.24, 134.12, 130.86,
130.84, 130.68 (2C), 129.56 (2C), 129.26 (2C), 129.14, 128.77, 127.41
(2C),123.04, 121.84,121.75,120.50,114.72,114.56, 55.67, 46.15. HRMS
(EI): m/z (Mþ) for C25H19ClFN3O2: calcd. 447.115; found 447.117.
132.00,131.73,131.35,131.28,129.96,129.02 (2C),128.21,127.96 (2C),
126.90 (2C), 126.64 (2C), 120.07, 115.84, 115.70, 54.87, 45.78. HRMS
(EI): m/z (Mþ) for C25H20FN3O2: calcd. 413.154; found 413.1553.
4.8.25. 2-Fluoro-N-(1-(4-fluorophenyl)-3-(1H-imidazol-1-yl)-1-
oxopropan-2-yl)-[1,10-biphenyl]-4-carboxamide (15y)
4.8.30. N-(3-(1H-imidazol-1-yl)-1-oxo-1-(p-tolyl)propan-2-yl)-
[1,10-biphenyl]-4-carboxamide (15ad)
Light white solid; yield: 49.0%; mp: 130.5e131.4 ꢀC. 1H NMR
Light white solid; yield: 48.3%; mp: 76.6e78.0 ꢀC. 1H NMR
(600 MHz, DMSO)
d
9.27 (d, J ¼ 8.2 Hz, 1H), 8.10 (dd, J ¼ 8.4, 5.6 Hz,
(600 MHz, DMSO)
d
9.14 (d, J ¼ 8.4 Hz, 1H), 7.94 (d, J ¼ 8.1 Hz, 2H),
2H), 7.68e7.61 (m, 4H), 7.58e7.55 (m, 2H), 7.50 (t, J ¼ 7.6 Hz, 2H),
7.46e7.42 (m, 1H), 7.37 (t, J ¼ 8.8 Hz, 2H), 7.22 (s, 1H), 6.84 (s, 1H),
5.78e5.74 (m, 1H), 4.58 (dd, J ¼ 14.1, 4.4 Hz, 1H), 4.42 (dd, J ¼ 14.0,
7.82 (d, J ¼ 8.2 Hz, 2H), 7.73 (d, J ¼ 8.3 Hz, 2H), 7.70 (d, J ¼ 7.6 Hz,
2H), 7.63 (s, 1H), 7.48 (t, J ¼ 7.6 Hz, 2H), 7.40 (t, J ¼ 7.3 Hz, 1H), 7.33
(d, J ¼ 8.1 Hz, 2H), 7.22 (s, 1H), 6.83 (s, 1H), 5.76e5.72 (m, 1H), 4.57
(dd, J ¼ 14.1, 4.5 Hz, 1H), 4.41 (dd, J ¼ 14.1, 9.6 Hz, 1H), 2.35 (s, 3H).
9.7 Hz, 1H). 13C NMR (150 MHz, DMSO)
d 195.92, 166.47, 164.91,
164.80, 159.96, 158.32, 138.40, 134.67, 134.61, 132.10, 131.98, 131.89,
131.83, 131.77, 131.45, 129.31, 129.30, 129.18, 128.93, 128.77, 124.25,
120.53, 116.36, 116.22, 115.53, 115.36, 55.37, 46.22. HRMS (EI): m/z
(Mþ) for C25H19F2N3O2: calcd. 431.1445; found 431.1447.
13C NMR (150 MHz, DMSO)
d 196.92, 166.08, 144.54, 143.68, 139.54,
138.38, 132.87, 132.58, 129.73 (2C), 129.50 (2C), 128.93 (2C), 128.72,
128.60 (2C), 128.44, 127.37 (2C), 127.08 (2C), 120.52, 55.24, 46.35,
21.65. HRMS (EI): m/z (Mþ) for C26H23N3O2: calcd. 409.179; found
409.1804.
4.8.26. 3-Fluoro-N-(1-(4-fluorophenyl)-3-(1H-imidazol-1-yl)-1-
oxopropan-2-yl)-[1,10-biphenyl]-4-carboxamide (15z)
4.8.31. N-(3-(1H-imidazol-1-yl)-1-oxo-1-(p-tolyl)propan-2-yl)-2-
fluoro-[1,10-biphenyl]-4-carboxamide (15ae)
Light white solid; yield: 41.2%; mp: 120.3e122.1 ꢀC. 1H NMR
(600 MHz, DMSO)
d
9.05 (d, J ¼ 8.2 Hz, 1H), 8.10 (dd, J ¼ 8.6, 5.5 Hz,
Light white solid; yield: 42.3%; mp: 148.3e150.1 ꢀC. 1H NMR
2H), 7.73e7.71 (m, 2H), 7.64 (s, 1H), 7.61e7.56 (m, 2H), 7.50e7.45
(m, 3H), 7.44e7.41 (m, 1H), 7.38 (t, J ¼ 8.8 Hz, 2H), 7.22 (s, 1H), 6.88
(s, 1H), 5.74 (td, J ¼ 8.8, 4.6 Hz, 1H), 4.59 (dd, J ¼ 14.2, 4.5 Hz, 1H),
(600 MHz, DMSO)
d
9.24 (d, J ¼ 8.5 Hz, 1H), 7.93 (d, J ¼ 8.2 Hz, 2H),
7.69e7.62 (m, 4H), 7.56 (d, J ¼ 8.1 Hz, 2H), 7.50 (t, J ¼ 7.6 Hz, 2H),
7.45e7.42 (m, 1H), 7.33 (d, J ¼ 8.1 Hz, 2H), 7.23 (s, 1H), 6.84 (s, 1H),
5.78e5.74 (m, 1H), 4.57 (dd, J ¼ 14.1, 4.5 Hz, 1H), 4.40 (dd, J ¼ 14.1,
4.40 (dd, J ¼ 14.2, 9.3 Hz, 1H). 13C NMR (150 MHz, DMSO)
d 195.80,
166.46, 164.79, 163.79, 160.84, 159.18, 145.33, 145.27, 138.38, 138.25,
132.09, 131.88, 131.82, 130.85, 130.83, 129.56 (2C), 129.13, 128.67,
127.41 (2C), 123.05, 123.03, 121.92, 121.83, 120.54, 116.30, 116.16,
114.71, 114.55, 55.55, 46.26. HRMS (EI): m/z (Mþ) for C25H19F2N3O2:
calcd. 431.1445; found 431.1456.
9.7 Hz,1H), 2.36 (s, 3H). 13C NMR (150 MHz, DMSO)
d 196.71,164.79,
159.95, 158.32, 144.64, 138.40, 134.78, 134.73, 134.62, 132.80, 131.91,
131.82, 131.45, 131.43, 129.77, 129.31, 129.30, 129.18, 128.93, 128.74,
124.26, 124.24, 120.53, 115.52, 115.36, 55.27, 46.34, 21.66. HRMS
(EI): m/z (Mþ) for C26H22FN3O2: calcd. 427.1696; found 427.1709.
4.8.27. N-(1-(4-chlorophenyl)-3-(1H-imidazol-1-yl)-1-oxopropan-
2-yl)-[1,10-biphenyl]-4-carboxamide (15aa)
4.9. The procedure for the synthesis of compound 18
Light white solid; yield: 48.3%; mp: 149.7e150.4 ꢀC. 1H NMR
The synthetic procedures of compound 18 were similar to those
used for compounds 15a-ae.
(600 MHz, DMSO)
d
9.20 (d, J ¼ 8.3 Hz, 1H), 8.01 (d, J ¼ 8.6 Hz, 2H),
7.80 (d, J ¼ 8.4 Hz, 2H), 7.74 (d, J ¼ 8.4 Hz, 2H), 7.70 (d, J ¼ 7.5 Hz,
2H), 7.62e7.58 (m, 3H), 7.48 (t, J ¼ 7.7 Hz, 2H), 7.40 (t, J ¼ 7.3 Hz,1H),
7.21 (s, 1H), 6.84 (s, 1H), 5.71 (td, J ¼ 9.0, 4.6 Hz, 1H), 4.59 (dd,
J ¼ 14.1, 4.5 Hz, 1H), 4.42 (dd, J ¼ 14.1, 9.5 Hz, 1H). 13C NMR
4.9.1. N-(1-oxo-1-phenyl-3-(1H-1,2,4-triazol-1-yl)propan-2-yl)-
[1,10-biphenyl]-4-carboxamide (18)
Light white solid; yield: 40.6%; mp: 117.1e119.0 ꢀC. 1H NMR
(150 MHz, DMSO)
d
196.63, 166.21, 143.77, 139.52, 138.83, 138.38,
(600 MHz, DMSO)
d
9.21 (d, J ¼ 8.3 Hz, 1H), 8.52 (s, 1H), 7.98 (d,
134.23, 132.42, 130.62 (2C), 129.49 (2C), 129.27 (2C), 128.76, 128.61,
128.42 (2C), 127.37 (2C), 127.12 (2C), 120.52, 55.49, 46.16. HRMS
(EI): m/z (Mþ) for C25H20ClN3O2: calcd. 429.1244; found 429.1251.
J ¼ 7.3 Hz, 2H), 7.96 (s, 1H), 7.80 (d, J ¼ 8.4 Hz, 2H), 7.73 (d, J ¼ 8.4 Hz,
2H), 7.71e7.68 (m, 2H), 7.62 (t, J ¼ 7.4 Hz, 1H), 7.52 (t, J ¼ 7.8 Hz, 2H),
7.48 (t, J ¼ 7.7 Hz, 2H), 7.40 (t, J ¼ 7.3 Hz, 1H), 5.83 (td, J ¼ 8.5, 5.0 Hz,
1H), 4.83 (dd, J ¼ 14.0, 4.9 Hz, 1H), 4.66 (dd, J ¼ 14.0, 8.8 Hz, 1H). 13
C
4.8.28. N-(1-(4-chlorophenyl)-3-(1H-imidazol-1-yl)-1-oxopropan-
2-yl)-2-fluoro-[1,10-biphenyl]-4-carboxamide (15 ab)
NMR (150 MHz, DMSO) d 196.90, 166.14, 151.98, 145.36, 143.73,
139.52, 135.34, 133.99, 132.47, 129.50, 129.15, 128.68, 128.61, 128.43,
127.37, 127.09, 54.51, 48.96. HRMS (EI): m/z (Mþ) for C24H20N4O2:
calcd. 396.1586; found 396.1589.
Light white solid; yield: 39.0%; mp: 147.1e148.3 ꢀC. 1H NMR
(600 MHz, DMSO)
d
9.28 (d, J ¼ 8.1 Hz, 1H), 8.01 (d, J ¼ 8.1 Hz, 2H),
7.67e7.60 (m, 6H), 7.58e7.55 (m, 2H), 7.50 (t, J ¼ 7.6 Hz, 2H),
7.46e7.42 (m, 1H), 7.22 (s, 1H), 6.85 (s, 1H), 5.74 (td, J ¼ 8.7, 4.7 Hz,
4.10. In vitro antifungal testing
1H), 4.59 (dd, J ¼ 14.2, 4.5 Hz, 1H), 4.42 (dd, J ¼ 14.0, 9.6 Hz, 1H). 13
C
NMR (150 MHz, DMSO)
d
196.42, 164.92, 159.96, 158.32, 138.91,
Five pathogenic fungi (Guangdong culture collection center) and
five fluconazole-resistant strains of Candida albicans were selected
to determine the in vitro minimum inhibitory concentrations (MIC)
according to the protocols of the Clinical Laboratory Standard
Institute (CLSI, formerly NCCLS). Fluconazole and itraconazole were
138.39, 134.60, 134.58, 134.15, 132.00, 131.91, 131.48, 131.46, 130.62,
129.31, 129.18, 128.93, 128.78, 124.24, 124.22, 120.53, 115.52, 115.36,
55.50, 46.15. HRMS (EI): m/z (Mþ) for C25H19ClFN3O2: calcd.
447.115; found 447.1158.

L. Zhao et al. / European Journal of Medicinal Chemistry 183 (2019) 111689
11
used as positive control drugs. The RPMI 1640 medium (Gibco, USA)
compounds described in this article.
was adjusted to pH 7.0 with 3-[N-morpholino]- propanesulfonic
acid (MOPS, Genyiew, USA). Fluconazole, itraconazole and the
target compounds were dissolved in DMSO and serially diluted into
the RPMI 1640 medium to achieve final concentrations ranged from
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The authors thank Hongwei Liu from Institute of Microbiology,
Chinese Academy of Sciences for providing the fluconazole-
resistant strains of Candida albicans (strains 17# and CaR). The au-
thors thank Prof. Yongbing Cao from School of Pharmacy, the Sec-
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resistant strains 632, 901 and 904. This work was supported by
Program for Innovative Research Team of the Ministry of Education
and Program for Liaoning Innovative Research Team in University.
Appendix. Supplementary data
Supplementary data associated with this article can be found in
the online version, at https://doi.org/10.1016/j.ejmech.2019.111689.
These data include MOL files and InChiKeys of the most important