Synthesis, spectroscopic characterization, X-ray structure, and in vivo neurotropic activity of new 1,5-benzodiazepin-2-ones

Article abstract of DOI:10.1007/s00044-016-1605-z

The paper reports the synthesis and in vivo pharmacological studies of a series of N-alkyl-1,5-benzodiazepine-2-ones. In this work, 19 novel benzodiazepine derivatives have been prepared and characterized by spectroscopic methods including 2D nuclear magnetic resonance techniques. Crystal structure of 1-benzyl-8-methyl-4-phenyl-1H-benzo[b][1,4]diazepin-2(3H)-one has also been determined by X-ray diffraction. Prediction of activity spectra for substances prediction and docking studies onto human serum albumin were conducted. Two compounds under these investigation showed high antihypoxic, tranquilizing, and anticonvulsant activity in vivo.

Full text of DOI:10.1007/s00044-016-1605-z

MEDICINAL
CHEMISTRY
RESEARCH
Med Chem Res
DOI 10.1007/s00044-016-1605-z
ORIGINAL RESEARCH
Synthesis, spectroscopic characterization, X-ray structure, and in vivo
neurotropic activity of new 1,5-benzodiazepin-2-ones
Alexandr A. Gaponov1 Elena T. Zlenko2 Svetlana V. Shishkina3
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Oleg V. Shishkin3 Oleksii M. Antypenko4 Serhii V. Tretiakov1
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1,5
Vitaliy A. Palchikov
Received: 17 April 2015 / Accepted: 1 June 2016
© Springer Science+Business Media New York 2016
Abstract The paper reports the synthesis and in vivo
pharmacological studies of a series of N-alkyl-1,5-benzo-
diazepine-2-ones. In this work, 19 novel benzodiazepine
derivatives have been prepared and characterized by spec-
troscopic methods including 2D nuclear magnetic resonance
techniques. Crystal structure of 1-benzyl-8-methyl-4-phe-
nyl-1H-benzo[b][1,4]diazepin-2(3H)-one has also been
determined by X-ray diffraction. Prediction of activity
spectra for substances prediction and docking studies onto
human serum albumin were conducted. Two compounds
under these investigation showed high antihypoxic, tran-
quilizing, and anticonvulsant activity in vivo.
substructural units. Benzodiazepines (BDZs) represent an
important class of pharmaceuticals and possess sedative,
hypnotic, anxiolytic, anticonvulsant, miorelaxant, amnesic,
antimicrobial, and antitumor activities (Borges et al., 2016;
Wang et al., 2015; Hammer et al., 2015; Gavai et al., 2015;
Olkkola and Ahonen, 2008; Page et al., 2002). They are
also used to treat a variety of conditions such as alcohol
addiction, seizures, anxiety, panic, agitation, and insomnia.
BDZ-based sedatives and hypnotics are among the most
prescribed drugs in the community (Drummer, 2009).
There are some differences in activity between 1,5- and 1,4-
BDZs. A greater therapeutic potential and lower incidence of
side effects were noted for 1,5-BDZs compared to 1,4-BDZs
(Pandeya and Rajput, 2012). 1,5-Benzodiazepin-2-ones have
been used in clinics as antisecretory, anxiolytic, and antic-
onvulsant agents. Examples thereof include, telenzepine (Eltze
et al., 1985), arfendazam (Hofmann et al., 1982), lofendazam
(Müller et al., 1986), triflubazam (Nicholson et al., 1977),
clobazam (Kruse, 1982), and CP-1414S (Carli et al., 1981;
Caccia et al., 1982). Members of this family also exhibit a
wide range of other activities such as interleukin-1β-converting
enzyme inhibition, antiarrhythmic properties (Claremon et al.,
1996), delayed rectifier potassium current blocking (Herpin
et al., 2000) and are used for adjuvant therapy of drug-resistant
epilepsy (Fisher and Blum, 1995). Furthermore, 2,3-dihydro-
1H-1,5-benzodiazepin-2-ones are viewed as potential imaging
agents for the metabotropic glutamate receptor subtype 2
(Gilfillan et al., 2013). As a result, benzodiazepin-2-ones are
considered as privileged scaffolds in drug discovery and in
drug development (Viviano et al., 2015; Welsch et al., 2010).
Starting from the 1960s, the important biological prop-
erties of these compounds have led to active synthetic work
and extensive pharmacological studies.
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Keywords Synthesis 1,5-Benzodiazepin-2-one Neurotropic
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activity Crystal structure Biological activity spectrum
Introduction
Many biologically active compounds, both natural and
synthetic in origin, incorporate azaheterocycles as
Elena T. Zlenko and Oleg V. Shishkin: Deceased
* Vitaliy A. Palchikov
palchikoff@mail.ru
1
Department of Chemistry, Oles Honchar Dnipropetrovsk National
University, Dnipropetrovsk, Ukraine
2
Dnipropetrovsk Medical Academy, Dnipropetrovsk, Ukraine
3
Institute for Single Crystals NAS of Ukraine, Kharkov, Ukraine
4
Zaporizhzhya State Medical University, Zaporizhzhya, Ukraine
5
We analyzed structures of 50 FDA approved drugs
containing 1,4- and 1,5-BDZ subunits and found that many
Peoples’ Friendship University of Russia, Moscow, Russian
Federation

Med Chem Res
Diazepam: R1 = Me, R2 = H, R3 = Ph, R4 = Cl; Prazepam: R1 = cyclopropylmethyl, R2 = H, R3 = Ph,
R4 = Cl; Pinazepam: R1 = propargyl, R2 = H, R3 = Ph, R4 = Cl; Halazepam: R1 = 2,2,2-trifluoroethyl,
R2 = H, R3 = Ph, R4 = Cl; Diclazepam: R1 = Me, R2 = H, R3 = 2-ClC6H4, R4 = Cl; Flurazepam: R1 =
Et2NCH2CH2, R2 = H, R3 = 2-FC6H4, R4 = Cl; Flutoprazepam: R1 = cyclopropylmethyl, R2 = H, R3
= 2-FC6H4, R4 = Cl; Nimetazepam: R1 = Me, R2 = H, R3 = Ph, R4 = NO2; Flunitrazepam: R1 = Me,
R2 = H, R3 = 2-FC6H4, R4 = NO2; Tetrazepam: R1 = Me, R2 = H, R3 = cyclohex-1-en-1-yl, R4 = Cl;
Temazepam: R1 = Me, R2 = OH, R3 = Ph, R4 = Cl; Lormetazepam: R1 = Me, R2 = OH, R3 = 2-ClC6H4,
R4 = Cl; Cinolazepam: R1 = NCCH2CH2, R2 = OH, R3 = 2-FC6H4, R4 = Cl
R1
N
O
R2
R4
N
R3
1,4-BDZ core drugs
R1
O
R4
R3
N
Arfendazam: R1 = Ph, R2 = EtOC(O), R3 = H, R4 = Cl, X = CH2; Lofendazam: R1 = Ph, R2 = H, R3
= H, R4 = Cl, X = CH2; Triflubazam: R1 = Me, R2 = Ph, R3 = CF3, R4 = H, X = C=O; Clobazam: R1
= Me, R2 = Ph, R3 = Cl, R4 = H, X = C=O
X
N
R2
1,5-BDZ core drugs
Fig. 1 General structures of some commercial drugs containing 1,4- or 1,5-BDZ core
compounds include N-alkylamide fragments (Fig. 1). We
therefore synthesized a family of 25 N-alkyl-1,5-benzodia-
zepine-2-ones and evaluated their biological potential in
silico using prediction of activity spectra for substances
(PASS, Goel et al., 2011) and molecular docking approa-
ches. The compounds were characterized using infrared
radiation (IR), 1H and 13C nuclear magnetic resonance
(NMR) spectroscopy, X-ray diffraction, and elemental
analysis. Two compounds were tested for neurotropic
(antihypoxic, tranquilizing, and anticonvulsant) properties.
We envision that synthetic and biological studies of the
novel 1,5-BDZs can be further expanded toward a greater
scope and utility.
UV-254 plates using diethyl ether and hexane as eluents; the
plates were visualized with iodine vapor.
X-ray diffraction study
The colourless crystals of compound 29 (C23H20N2O) are
monoclinic. At 293 K, a = 9.540(3), b = 12.832(1), c =
14.928(3) Ǻ, β = 94.47(2)°, V = 1821.9(7) Ǻ3, Mr = 340.41,
Z = 4, space group P21/n, dcalc = 1.241 g/сm3, μ(MoKα) =
0.077 mm−1, F(000) = 720. Intensities of 8854 reflections
(3164 independent, Rint = 0.020) were measured on an
Xcalibur-3 diffractometer (graphite-monochromated MoKα
radiation, CCD detector, ω-scanning, 2Θmax = 50°). The
structure was solved by direct methods using SHELXTL
package (Sheldrick, 2008). Positions of the hydrogen atoms
were located from electron density difference maps and
refined by “riding” the model with Uiso = nUeq (n = 1.5 for
methyl group and n = 1.2 for other hydrogen atoms) of the
carrier atom. Full-matrix least-squares refinement against F2
in anisotropic approximation for nonhydrogen atoms using
3127 reflections was converged to wR2 = 0.096 (R1 = 0.036
for 1875 reflections with F 4 4σ(F), S = 0.862). The final
atomic coordinates and crystallographic data for the mole-
cule 29 have been deposited to the Cambridge Crystal-
lographic Data Centre, 12 Union Road, CB2 1EZ, UK (fax:
+44-1223-336033; e-mail: deposit@ccdc.cam.ac.uk) and
are available on request quoting the deposition number
CCDC 1044106.
Experimental methods
Chemistry
Solvents were dried and distilled immediately prior to use.
Melting points were determined in open capillary tubes and
reported uncorrected. IR spectra were recorded on a UR-20 or
Specord 75IR spectrometer using KBr pellets. NMR spectra
were measured on Varian VXR, Bruker Spectrospin DPX-
400 (only for 2D NMR spectra of compound 27), or Bruker
Avance DRX-500 spectrometer at room temperature in
appropriate solvents. Chemical shifts are reported in parts per
million (ppm) with respect to the solvent residual signal
(CDCl3 1H: δ = 7.26 ppm, 13C: δ = 77.16 ppm; dimethyl
sulfoxide (DMSO)-d6 1H: δ = 2.50 ppm, 13C: δ = 39.52 ppm).
Coupling constants (J) are reported in Hertz (Hz). Low
resolution mass-spectra of compounds 34, 35 were recorded
on a Varian 1200L spectrometer in electron impact ionization
mode at the energy of 70 eV. The elemental analysis (C, H,
N) was performed using Carlo Erba analyzer. The analytical
results were within 0.4 % of the theoretical values. Thin-
layer chromatography (TLC) was performed on Silufol
The starting BDZs 1–8 were prepared according to the
literature procedures (Vernin et al., 1980; El-Shafei et al.,
1982). Their physical and spectral data were in correspon-
dence with those reported (Vernin et al., 1980; El-Shafei
et al., 1982). Compounds 10, 17, 22, 24, and 28 were
described by Solomko et al. (1990) and El-Shafei et al.
(1982) without spectral data. The NMR spectra of com-
pounds 18, 19, and 20 in CDCl3 were described in Chen
et al. (2011) and Essassi et al. (1987) without IR data.

Med Chem Res
General procedures for the synthesis of substituted benzo
[b][1,4]diazepin-2(3H)-ones (9–35)
was filtered off and the solvent was removed in vacuo. The
residue was then dissolved in 10 mL of chloroform and
washed with brine (2 × 10 mL), dried over Na2SO4, and
concentrated in vacuo to afford the crude product. Pure
compounds 10, 12, 14, 16–19, 22–24, 27–29, 33 were
obtained after recrystallization from hexane (or
hexane–benzene mixture) or by flash chromatography on
silica (hexane–ethyl acetate, 3:1 v/v).
Method C: A stirred mixture of the benzodiazepin-2-one
1 or 4 (5 mmol) and sodium hydride (60 % in oil, 0.40 g, 10
mmol) in N,N-Dimethylformamide (20 mL) was heated to
100 °C over 0.5 h. 2-(Chloromethyl)oxirane (0.93 g, 10
mmol) was then added dropwise, and the reaction mixture
was heated for additional 3 h. Upon cooling to room tem-
perature, the solid was filtered off and the filtrate was
poured into brine. The aqueous phase was extracted with
chloroform (3 × 30 mL). The combined organic layers were
washed with brine (25 mL) and dried over Na2SO4. The
solvent was removed in vacuo to afford the crude product.
Pure compounds 13 and 21 were obtained after recrys-
tallization from hexane (or hexane–benzene mixture).
Method A: The appropriate benzodiazepin-2-one (5 mmol,
see Table 1), tetrabutylammonium bromide (TBAB, 0.097
g, 0.3 mmol), and 50 % aqueous NaOH (3 ml) were mixed
in benzene (30 mL) at room temperature. The alkyl halide
(10 mmol, see Table 1) was added dropwise to the stirred
mixture. The stirring was continued at 60 °C for 1.5 h. After
cooling, the benzene layer was separated and washed with
brine (2 × 10 mL), then dried over Na2SO4. The solvent was
removed in vacuo to afford the crude product. Pure com-
pounds 9–12, 14–20, 22–35 were obtained after recrys-
tallization from hexane (or hexane–benzene mixture) or by
flash chromatography on silica (hexane–ethyl acetate, 3:1 v/
v).
Method B: The appropriate alkyl halide (10 mmol, see
Table 1) was added dropwise to the stirred mixture of the
benzodiazepin-2-one (5 mmol, see Table 1) and potassium
hydroxide (1.40 g, 25 mmol) in acetone (30 mL). The
reaction was heated at reflux for 3 h. After cooling, the solid
Table 1 Synthesized
N-alkyl-BDZs 9-33
Starting
compound
R1
R2 R3
R4
R1-X (alkylating
agent)
Product Method (A/B/C),
yield (%)
1
1
1
1
1
Me
Et
Me
Me
Me
Me
H
H
H
H
H
H
H
H
H
H
MeI
9
A, 93
EtBr
10
11
12
13
A, 90; B, 82
A, 72
n-Pr
Bn
n-PrCl
BnCl
A, 74; B, 78
C, 79
2,3-Epoxypropyl Me
2-(Chloromethyl)
oxirane
2
3
3
4
4
4
4
4
Me
Me
Bn
Me
Me
Me
Ph
H
H
H
H
H
H
H
H
Cl
Me
Me
H
MeI
14
15
16
17
18
19
20
21
A, 88; B, 81
A, 76
MeI
BnCl
MeI
A, 78; B, 75
А, 92; B, 89
A, 88; B, 91
A, 94; B, 90
A, 86
Me
Et
Ph
H
EtBr
BnCl
Allyl-Br
Bn
Ph
H
Allyl
Ph
H
2,3-Epoxypropyl Ph
H
2-(Chloromethyl)
oxirane
C, 77
5
5
6
6
6
6
7
7
7
8
8
8
Me
Bn
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
H
H
H
H
H
H
H
H
H
Cl
Cl
MeI
22
23
24
25
26
27
28
29
30
31
32
33
A, 77; B, 81
A, 80; B, 74
A, 85; B, 77
A, 88
BnCl
Me
Et
OMe MeI
OMe EtBr
OMe BnCl
OMe Allyl-Br
Bn
A, 91
Allyl
Me
Bn
A, 83; B, 85
A, 87; B, 79
A, 90; B, 94
A, 88
Me
Me
Me
H
MeI
BnCl
Allyl
Me
Et
Allyl-Br
MeI
Ph NO2
Ph NO2
Ph NO2
A, 82
H
EtBr
A, 79
Allyl
H
Allyl-Br
A, 80; B, 75

Med Chem Res
The yield, melting point, and spectral data for each
compound are given below.
3.02 (m, 2Н, СН2), 3.81 (m, 2Н, СН2), 4.15 (m, 1Н, СН),
5.35 (d, 1Н, J = 11.0, С(О)СН2), 5.87 (d, 1Н, J = 11.0,
С(О)СН2), 7.18 (m, 3Н, HAr), 7.48 (s, 1Н, HAr); anal. calcd.
for C13H14N2O2 (230.27): C, 67.81; H, 6.13; N, 12.17;
found: C, 67.52; H, 5.87; N, 12.40.
1,4-Dimethyl-1H-benzo[b][1,4]diazepin-2(3H)-one (9)
Yield: method A, 0.88 g (93 %); m.p. 28–29 °C (28 °C
(El-Shafei et al., 1982)); IR (KBr) cm−1: 1670, 1610, 1585;
1H NMR (500 MHz, DMSO-d6): 2.30 (s, 3H, C–CH3), 2.76
(d, 1H, J = 11.4, CH2), 3.28 (d, 1H, J = 11.8, CH2), 3.30
(s, 3H, N–CH3), 7.15 (m, 3H, HAr), 7.32 (d, 1H, J = 7.6,
HAr); anal. calcd. for C11H12N2O (188.23): C, 70.19;
H, 6.43; N, 14.88; found: C, 70.02; H, 6.46; N, 15.07.
8-Chloro-1,4-dimethyl-1H-benzo[b][1,4]diazepin-2(3H)-
one (14) Yield: method A, 0.98 g (88 %); method B, 0.90
g (81 %); m.p. 107–108 °C; IR (KBr) cm−1: 1690, 1600,
1560; 1H NMR (400 MHz, DMSO-d6): 2.32 (s, 3H,
C–CH3), 2.78 (d, 1H, J = 11.1, CH2), 3.30 (s, 3H, N–CH3),
3.35 (d, 1H, J = 11.7, CH2), 7.13 (dd, 2H, J = 7.1, 2.6, HAr),
7.32 (d, 1H, J = 2.6, HAr); anal. calcd. for C11H11ClN2O
(222.67): C, 59.33; H, 4.98; N, 12.58; found: C, 59.27;
H, 5.04; N, 12.36.
1-Ethyl-4-methyl-1H-benzo[b][1,4]diazepin-2(3H)-one
(10) Yield: method A, 0.91 g (90 %); method B, 0.83 g
(82 %); m.p. 129–130 °C (130 °C (Vernin et al., 1980)),
130 °C (El-Shafei et al., 1982); IR (KBr) cm−1: 1675, 1605,
1590; 1H NMR (500 MHz, DMSO-d6): 0.98 (t, 3H, J = 7.1,
CH2CH3), 2.24 (s, 3H, C–CH3), 2.79 (d, 1H, J = 11.3, C(O)
СH2), 3.30 (d, 1H, J = 11.3, C(O)СH2), 3.73 (m, 1H,
CH2CH3), 4.00 (m, 1H, CH2CH3), 7.23 (m, 3H, HAr), 7.49
(d, 1Н, J = 7.7, HAr); 13C NMR (125 MHz, DMSO-d6):
13.29 (CH2CH3), 27.00 (C–CH3), 41.88 (CH2CH3), 43.61
(C(O)СH2), 122.59 (CAr), 125.10 (CAr), 125.78 (CAr),
126.19 (CAr), 133.23 (CAr), 141.89 (CAr), 164.07 (C=N),
165.30 (С=О); anal. calcd. for C12H14N2O (202.26):
C, 71.26; H, 6.98; N, 13.85; found: C, 71.05; H, 6.80;
N, 13.99.
1,4,8-Trimethyl-1H-benzo[b][1,4]diazepin-2(3H)-one
(15) Yield: method A, 0.77 g (76 %); m.p. 103–104 °C; IR
(KBr) cm−1: 1680, 1605, 1535; 1H NMR (400 MHz,
DMSO-d6): 2.28 (s, 3H, N = C–CH3), 2.37 (s, 3H, C–CH3),
2.74 (d, 1H, J = 11.2, CH2), 3.25 (d, 1H, J = 11.6, CH2),
3.30 (s, 3H, N–CH3), 6.96 (d, 1H, J = 8.3, HAr), 7.05
(d, 1H, J = 8.3, HAr), 7.10 (s, 1H, HAr); anal. calcd. for
C12H14N2O (202.26): C, 71.26; H, 6.98; N, 13.85; found:
C, 71.02; H, 7.10; N, 13.98.
1-Benzyl-4,8-dimethyl-1H-benzo[b][1,4]diazepin-2(3H)-
one (16) Yield: method A, 1.09 g (78 %); method B, 1.04
g (75 %); m.p. 119–120 °C; IR (KBr) cm−1: 1675, 1600,
1560; 1H NMR (500 MHz, DMSO-d6): 2.25 (s, 3H,
N=C–CH3), 2.28 (s, 3H, C–CH3), 2.97 (d, 1H, J = 10.6,
C(O)СH2), 3.39 (d, 1H, J = 10.6, C(O)СH2), 4.99 (d, 1H,
J = 15.9, CH2C6H5), 5.26 (d, 1H, J = 15.9, CH2C6H5),
6.98 (d, 1H, J = 6.7, HAr), 7.07 (d, 2H, J = 8.1, HAr), 7.14
(m, 1H, HAr), 7.24 (m, 3H, HAr), 7.28 (s, 1H, HAr);
13C NMR (125 MHz, DMSO-d6): 20.62 (C–CH3),
26.86 (N=C–CH3), 43.35 (C(O)СH2), 49.18 (CH2C6H5),
122.48 (CAr), 125.98 (CAr), 126.09 (CAr), 126.26 (CAr),
126.84 (CAr), 128.39 (CAr), 128.76 (CAr), 132.98 (CAr),
135.02 (CAr), 137.60 (C–CH3), 139.52 (CAr), 164.35
(C=N), 164.62 (С=О); anal. calcd. for C18H18N2O
(278.36): C, 77.67; H, 6.52; N, 10.06; found: C, 77.48;
H, 6.45; N, 9.94.
4-Methyl-1-propyl-1H-benzo[b][1,4]diazepin-2(3H)-one
(11) Yield: method A, 0.91 g (72 %); m.p. 68–69 °C
(70 °C (Vernin et al., 1980)); IR (KBr) cm−1: 1670, 1605,
1580; 1H NMR (400 MHz, DMSO-d6): 0.74 (t, 3H,
СH2CH2CH3), 1.36 (m, 1H, СH2CH2CH3), 1.48 (m, 1H,
СH2CH2CH3), 2.28 (s, 3H, C–CH3), 2.73 (d, 1H, J = 10.8,
C(O)СH2), 3.27 (d, 1H, J = 11.4, C(O)СH2), 3.55 (m, 1H,
СH2CH2CH3), 4.10 (m, 1H, СH2CH2CH3), 7.14 (m, 3H,
HAr), 7.30 (d, 1Н, J = 7.9, HAr); anal. calcd. for C13H16N2O
(216.28): C, 72.19; H, 7.46; N, 12.95; found: C, 71.98;
H, 7.50; N, 13.07.
1-Benzyl-4-methyl-1H-benzo[b][1,4]diazepin-2(3H)-one
(12) Yield: method A, 0.98 g (74 %); method B, 1.03 g
(78 %); m.p. 124–125 °C (124 °C (Vernin et al., 1980)); IR
(KBr) cm−1: 1685, 1610, 1590; 1H NMR (400 MHz,
DMSO-d6): 2.33 (s, 3H, CH3), 2.94 (d, 1H, J = 11.0, C(O)
СH2), 3.40 (d, 1H, J = 11.5, C(O)СH2), 5.03 (dd, 2H,
J = 7.0, 2.5, CH2C6H5), 7.02 (d, 2H, J = 7.3, HAr), 7.15 (m,
4H, HAr), 7.24 (m, 2H, HAr), 7.31 (d, 1H, J = 7.4, HAr);
anal. calcd. for C17H16N2O (264.33): C, 77.25; H, 6.10;
N, 10.60; found: C, 77.12; H, 5.97; N, 10.44.
1-Methyl-4-phenyl-1H-benzo[b][1,4]diazepin-2(3H)-one
(17) Yield: method A, 1.15 g (92 %); method B, 1.12 g
(89 %); m.p. 66–67 °C; IR (KBr) cm−1: 1680, 1640, 1615,
1
1580. H NMR (500 MHz, DMSO-d6): 2.98 (d, 1H, J =
12.2, CH2), 3.30 (s, 3H, CH3), 4.14 (d, 1H, J = 12.4, CH2),
7.33 (m, 2H, HAr), 7.40 (dd, 1H, J = 7.7, 1.7, HAr), 7.55 (m,
4H, HAr), 8.09 (dd, 2Н, J = 8.0, 1.5, HAr); 13C NMR
(125 MHz, DMSO-d6): 34.69 (CH3), 39.68 (C(O)СH2),
122.30 (CAr), 125.07 (CAr), 126.30 (CAr), 127.67 (CAr),
128.83 (CAr), 131.30 (CAr), 134.94 (CAr), 136.81 (CAr),
140.98 (CAr), 160.32 (C=N), 165.67 (С=О); anal. calcd. for
1-(2,3-Epoxypropyl)-4-methyl-1H-benzo[b][1,4]diazepin-2
(3H)-one (13) Yield: method C, 0.91 g (79 %); m.p.
128–130 °C; IR (KBr) cm−1: 1670, 1610, 1580, 1260, 925,
1
860; H NMR (400 MHz, DMSO-d6): 2.30 (s, 3H, CH3),

Med Chem Res
C16H14N2O (250.30): C, 76.78; H, 5.64; N, 11.19; found:
C, 76.61; H, 5.54; N, 11.04.
1-(2,3-Epoxypropyl)-4-phenyl-1H-benzo[b][1,4]diazepin-2
(3H)-one (21) Yield: method C, 1.13 g (77 %); m.p.
74–76 °C; IR (KBr) cm−1: 1680, 1620, 1580, 1255, 925,
1-Ethyl-4-phenyl-1H-benzo[b][1,4]diazepin-2(3H)-one
(18) Yield: method A, 1.16 g (88 %); method B, 1.20 g
(91 %); m.p. 75–76 °C (72–74 °C (Vernin et al., 1980);
78–80 °C (Essassi et al., 1987)); IR (KBr) cm−1: 1675,
1
855; H NMR (400 MHz, DMSO-d6): 2.78 (m, 2Н, СН2),
3.98 (m, 2Н, СН2), 4.31 (m, 1Н, СН), 5.58 (d, 1Н, J = 11.5,
С(О)СН2), 6.16 (d, 1Н, J = 11.5, С(О)СН2), 6.70 (m, 1Н,
HAr), 7.20 (m, 8Н, HAr); anal. calcd. for C18H16N2O2
(292.34): C, 73.95; H, 5.52; N, 9.58; found: C, 74.22; H,
5.47; N, 9.85.
1
1635, 1615, 1580; H NMR (500 MHz, DMSO-d6): 0.98
(t, 3H, J = 7.1, CH3), 2.96 (d, 1H, J = 12.1, C(O)СH2), 3.76
(q, 1H, J = 7.1, CH2CH3), 4.03 (q, 1H, J = 7.1, CH2CH3),
4.11 (d, 1H, J = 12.1, C(O)СH2), 7.33 (m, 2H, HAr), 7.39
(dd, 1H, J = 7.4, 2.1, HAr), 7.55 (m, 4H, HAr), 8.09 (dd, 2Н,
J = 7.9, 1.5, HAr); 13C NMR (125 MHz, DMSO-d6): 13.33
(CH3), 39.69 (C(O)СH2), 41.90 (CH2CH3), 122.61 (CAr),
125.31 (CAr), 126.34 (CAr), 126.88 (CAr), 127.70 (CAr),
128.81 (CAr), 131.27 (CAr), 133.36 (CAr), 136.84 (CAr),
141.97 (CAr), 160.71 (C=N), 164.50 (С=О); anal. calcd. for
C17H16N2O (264.33): C, 77.25; H, 6.10; N, 10.60; found:
C, 76.96; H, 5.94; N, 10.79.
8-Chloro-1-methyl-4-phenyl-1H-benzo[b][1,4]diazepin-2
(3H)-one (22) Yield: method A, 1.10 g (77 %); method B,
1.16 g (81 %); m.p. 85–86 °C; IR (KBr) cm−1: 1690, 1630,
1
1605, 1575; H NMR (500 MHz, DMSO-d6): 3.05 (d, 1H,
J = 11.3, C(O)CH2), 3.30 (s, 3H, CH3), 4.17 (d, 1H, J =
10.9, C(O)CH2), 7.35 (d, 1H, J = 9.6, HAr), 7.41 (d, 1H,
J = 8.6, HAr), 7.55 (m, 3H, HAr), 7.64 (s, 1H, HAr), 8.09
(d, 2Н, J = 7.0, HAr); 13C NMR (125 MHz, DMSO-d6):
34.63 (NCH3), 39.69 (C(O)СH2), 122.05 (CAr), 125.01
(CAr), 127.70 (CAr), 128.39 (CAr), 128.81 (CAr), 130.01
(CAr), 131.45 (CAr), 135.93 (CAr), 136.49 (CAr–Cl), 139.84
(CAr), 160.80 (C=N), 165.46 (С=О); anal. calcd. for
C16H13ClN2O (284.74): C, 67.49; H, 4.60; N, 9.84; found:
C, 67.68; H, 4.53; N, 9.98.
1-Benzyl-4-phenyl-1H-benzo[b][1,4]diazepin-2(3H)-one
(19) Yield: method A, 1.52 g (94 %); method B, 1.46 g
(90 %); m.p. 128–129 °C (128 °C (Vernin et al., 1980)); IR
1
(KBr) cm−1: 1670, 1630, 1610, 1575; H NMR (500 MHz,
DMSO-d6): 3.17 (d, 1H, J = 11.8, C(O)СH2), 4.24 (d, 1H, J
= 11.9, C(O)СH2), 5.05 (d, 1H, J = 16.1, CH2C6H5), 5.28
(d, 1H, J = 16.0, CH2C6H5), 6.97 (d, 2H, J = 7.1, HAr), 7.14
(m, 1H, HAr), 7.20 (m, 2H, HAr), 7.25 (s, 2H, HAr), 7.36 (s,
1-Benzyl-8-chloro-4-phenyl-1H-benzo[b][1,4]diazepin-2
(3H)-one (23) Yield: method A, 1.44 g (80 %); method B,
1.34 g (74 %); m.p. 131–132 °C; IR (KBr) cm−1: 1680,
1635, 1610, 1580; 1H NMR (500 MHz, DMSO-d6): 3.17 (d,
1H, J = 11.8, C(O)СH2), 4.24 (d, 1H, J = 11.9, C(O)СH2),
5.08 (d, 1H, J = 16.0, CH2C6H5), 5.28 (d, 1H, J = 15.9,
CH2C6H5), 6.95 (d, 2H, J = 7.1, HAr), 7.18 (m, 4H, HAr),
7.31 (d, 1H, J = 11.9, HAr), 7.52 (m, 4H, HAr), 8.14 (d, 2Н,
J = 7.2, HAr); anal. calcd. for C22H17ClN2O (360.84): C,
73.23; H, 4.75; N, 7.76; found: C, 73.50; H, 4.79; N, 7.54.
1H, HAr), 7.56 (m, 4H, HAr), 8.12 (d, 2Н, J = 7.3, HAr); 13
C
NMR (125 MHz, DMSO-d6): 39.69 (C(O)СH2), 49.27
(CH2C6H5), 122.50 (CAr), 125.35 (CAr), 126.17 (CAr),
126.29 (CAr), 126.81 (CAr), 126.89 (CAr), 127.74 (CAr),
128.40 (CAr), 128.81 (CAr), 131.29 (CAr), 133.29 (CAr),
136.79 (CAr), 137.41 (CAr), 141.81 (CAr), 160.70 (C=N),
165.16 (С=О); anal. calcd. for C22H18N2O (326.40): C,
80.96; H, 5.56; N, 8.58; found: C, 81.21; H, 5.39; N, 8.48.
8-Methoxy-1-methyl-4-phenyl-1H-benzo[b][1,4]diazepin-2
(3H)-one (24) Yield: method A, 1.19 g (85 %); method B,
1.08 g (77 %); m.p. 92–93 °C; IR (KBr) cm−1: 1675, 1640,
1-Allyl-4-phenyl-1H-benzo[b][1,4]diazepin-2(3H)-one
(20) Yield: method A, 1.19 g (86 %); m.p. 106–108 °C
(108 °C (Vernin et al., 1980)); IR (KBr) cm−1: 1675, 1620,
1
1600, 1580; H NMR (500 MHz, DMSO-d6): 2.98 (d, 1H,
J = 12.1, C(O)СH2), 3.32 (s, 3H, N–CH3), 3.84 (s, 3H,
CH3), 4.12 (d, 1H, J = 12.1, C(O)СH2), 6.94 (dd, 1H, J =
8.6, 2.2, HAr), 7.03 (d, 1H, J = 2.2, HAr), 7.33 (d, 1H, J =
8.8, HAr), 7.52 (d, 3H, J = 6.6, HAr), 8.06 (dd, 2Н, J = 7.8,
1.6, HAr); 13C NMR (125 MHz, DMSO-d6): 34.76 (NCH3),
39.69 (C(O)СH2), 55.57 (OCH3), 106.49 (CAr), 112.02
(CAr), 127.40 (CAr), 128.17 (CAr), 128.71 (CAr), 130.88
(CAr), 134.93 (CAr), 135.84 (CAr), 136.94 (CAr), 157.34
(C=N), 158.24 (C–OCH3), 165.30 (С=О); anal. calcd. for
C17H16N2O2 (280.33): C, 72.84; H, 5.75; N, 9.99; found: C,
72.94; H, 5.79; N, 10.05.
1
1605, 1575; H NMR (500 MHz, DMSO-d6): 3.06 (d, 1H,
J = 12.1, C(O)СH2), 4.17 (d, 1H, J = 12.1, C(O)СH2), 4.49
(q, 2H, J = 15.0, CH2–CH=CH2), 4.95 (d, 1H, J = 16.9,
CH2–CH=CH2), 5.03 (d, 1H, J = 10.4, CH2–CH=CH2),
5.73 (m, 1H, CH2–CH=CH2), 7.31 (dd, 2H, J = 9.3, 2.1,
HAr), 7.40 (d, 1H, J = 9.3, HAr), 7.55 (d, 4H, J = 7.2, HAr),
8.10 (d, 2Н, J = 7.5, HAr); 13C NMR (125 MHz, DMSO-
d6): 39.69 (C(O)СH2), 49.01 (CH2–CH=CH2), 115.93
(CH2–CH=CH2), 122.36 (CAr), 125.25 (CAr), 126.20
(CAr), 126.81 (CAr), 127.65 (CAr), 128.76 (CAr), 131.25
(CAr), 133.58 (CAr), 133.64 (CH2–CH=CH2), 136.71 (CAr),
141.54 (CAr), 160.58 (C=N), 164.68 (С=О); anal. calcd. for
C18H16N2O (276.34): C, 78.24; H, 5.84; N, 10.14; found:
C, 78.52; H, 5.90; N, 10.08.
1-Ethyl-8-methoxy-4-phenyl-1H-benzo[b][1,4]diazepin-2
(3H)-one (25) Yield: method A, 1.29 g (88 %); m.p.
154–155 °C; IR (KBr) cm−1: 1680, 1630, 1605, 1570;

Med Chem Res
1H NMR (500 MHz, DMSO-d6): 0.97 (t, 3H, J = 7.0,
CH2CH3), 2.97 (d, 1H, J = 11.1, C(O)СH2), 3.78 (d, 1H, J
= 11.2, C(O)СH2), 3.84 (s, 3H, CH3), 4.09 (q, 2H, J = 7.0,
CH2CH3), 6.95 (dd, 1H, J = 8.5, 1.7, HAr), 7.05 (s, 1H,
HAr), 7.33 (d, 1H, J = 8.8, HAr), 7.52 (d, 3H, J = 6.1, HAr),
8.06 (d, 2Н, J = 6.4, HAr); 13C NMR (125 MHz, DMSO-
d6): 13.19 (CH2CH3), 39.69 (C(O)СH2), 41.84 (CH2CH3),
55.54 (OCH3), 106.76 (CAr), 112.27 (CAr), 127.43 (CAr),
128.19 (CAr), 128.69 (CAr), 130.86 (CAr), 134.15 (CAr),
136.01 (CAr), 136.96 (CAr), 157.35 (C=N), 158.72
(C–OCH3), 164.17 (С=О); anal. calcd. for C18H18N2O2
(294.35): C, 73.45; H, 6.16; N, 9.52; found: C, 73.40; H,
6.02; N, 9.70.
1,8-Dimethyl-4-phenyl-1H-benzo[b][1,4]diazepin-2(3H)-
one (28) Yield: method A, 1.15 g (87 %); method B, 1.05
g (79 %); m.p. 91–92 °C; IR (KBr) cm−1: 1690, 1620, 1605;
1H NMR (500 MHz, DMSO-d6): 2.39 (s, 3H, C–CH3), 2.97
(d, 1H, J = 11.7, C(O)CH2), 3.29 (s, 3H, N–CH3), 4.11 (d,
1H, J = 11.7, C(O)CH2), 7.12 (d, 1H, J = 8.0, HAr), 7.28 (d,
1H, J = 8.0, HAr), 7.34 (s, 1H, HAr), 7.53 (d, 3H, J = 6.9,
HAr), 8.07 (d, 2Н, J = 7.2, HAr); 13C NMR (125 MHz,
DMSO-d6): 20.72 (C–CH3), 34.60 (N–CH3), 39.68 (C(O)
СH2), 122.23 (CAr), 125.95 (CAr), 126.66 (CAr), 127.49
(CAr), 128.72 (CAr), 131.05 (CAr), 134.66 (CAr), 135.83
(CAr), 136.85 (C–CH3), 138.70 (CAr), 159.44 (C=N),
165.44 (С=О); anal. calcd. for C17H16N2O (264.33): C,
77.25; H, 6.10; N, 10.60; found: C, 77.39; H, 5.97; N,
10.78.
1-Benzyl-8-methoxy-4-phenyl-1H-benzo[b][1,4]diazepin-2
(3H)-one (26) Yield: method A, 1.62 g (91 %); m.p.
1
99–100 °C; IR (KBr) cm−1: 1675, 1625, 1600; H NMR
1-Benzyl-8-methyl-4-phenyl-1H-benzo[b][1,4]diazepin-2
(3H)-one (29) Yield: method A, 1.53 g (90 %); method B,
1.60 g (94 %); m.p. 145–146 °C; IR (KBr) cm−1: 1680, 1615,
(500 MHz, DMSO-d6): 3.08 (d, 1H, J = 11.8, C(O)СH2),
3.71 (s, 3H, CH3), 4.13 (d, 1H, J = 11.9, C(O)СH2), 5.11 (s,
2H, CH2C6H5), 6.79 (dd, 1H, J = 7.2, 2.4, HAr), 6.87 (d,
1H, J = 6.7, HAr), 7.07 (d, 2H, J = 8.6, HAr), 7.19 (m, 4H,
HAr), 7.49 (d, 3H, J = 6.3, HAr), 8.10 (d, 2Н, J = 7.2, HAr);
anal. calcd. for C23H20N2O2 (356.43): C, 77.51; H, 5.66; N,
7.86; found: C, 77.38; H, 5.51; N, 7.92.
1
1575; H NMR (500 MHz, DMSO-d6): 2.29 (s, 3H, CH3),
3.14 (d, 1H, J = 11.7, C(O)СH2), 4.20 (d, 1H, J = 11.7, C(O)
СH2), 5.03 (d, 1H, J = 16.1, CH2C6H5), 5.30 (d, 1H, J =
16.1, CH2C6H5), 6.95 (d, 2H, J = 7.3, HAr), 7.07 (d, 1H, J =
8.0, HAr), 7.19 (m, 4H, HAr), 7.37 (s, 1H, HAr), 7.55 (d, 3H,
J = 6.1, HAr), 8.10 (d, 2Н, J = 6.4, HAr); 13C NMR
(125 MHz, DMSO-d6): 20.70 (C–CH3), 39.69 (C(O)СH2),
49.17 (CH2C6H5), 122.58 (CAr), 126.22 (CAr), 126.35 (CAr),
126.69 (CAr), 126.85 (CAr), 127.64 (CAr), 128.36 (CAr),
128.76 (CAr), 131.11 (CAr), 133.05 (CAr), 135.72 (CAr),
136.91 (CAr), 137.52 (C–CH3), 139.69 (CAr), 159.97 (C=N),
165.00 (С=О); anal. calcd. for C23H20N2O (340.43): C,
81.15; H, 5.92; N, 8.23; found: C, 81.09; H, 5.80; N, 8.29.
1-Allyl-8-methoxy-4-phenyl-1H-benzo[b][1,4]diazepin-2
(3H)-one (27) Yield: method A, 1.27 g (83 %); method B,
1.31 g (85 %); m.p. 106–108 °C; IR (KBr) cm−1: 1668,
1
1606, 1563; H NMR (400 MHz, DMSO-d6): 3.06 (d, 1H,
J = 11.9, C(O)СH2), 3.79 (s, 3H, CH3), 4.14 (d, 1H,
J = 11.9, C(O)СH2), 4.49 (m, 2H, CH2–CH=CH2), 4.97
(d, 1H, J = 17.3, CH2–CH=CH2), 5.05 (d, 1H, J = 10.5,
CH2–CH=CH2), 5.74 (m, 1H, CH2–CH=CH2), 6.94 (dd,
1H, J = 8.8, 2.2, HAr), 7.05 (s, 1H, HAr), 7.33 (d, 1H, J =
8.8, HAr), 7.53 (m, 3H, HAr), 8.06 (d, 2H, J = 7.6, HAr); 1H
NMR (400 MHz, CDCl3): 3.01 (d, 1H, J = 11.7, C(O)СH2),
3.75 (s, 3H, CH3), 4.09 (d, 1H, J = 11.7, C(O)СH2), 4.26 (d,
1H, J = 15.2, CH2–CH=CH2), 4.50 (d, 1H, J = 15.2,
CH2–CH=CH2), 5.09 (m, 2H, CH2–CH=CH2), 5.83 (m,
1H, CH2–CH=CH2), 6.80 (d, 1H, J = 8.9, HAr), 6.89 (s, 1H,
HAr), 7.36 (m, 4H, HAr), 8.06 (m, 2H, HAr); 13C NMR
(100 MHz, DMSO-d6): 39.68 (C(O)СH2), 49.28
(CH2–CH=CH2), 55.55 (OCH3), 106.71 (CAr), 112.30
(CAr), 116.05 (CH2–CH=CH2), 127.55 (CAr), 128.32 (CAr),
128.81 (CAr), 131.02 (CAr), 133.79 (CH2–CH=CH2),
134.69 (CAr), 135.63 (CAr), 136.98 (CAr), 157.33 (C=N),
158.71 (C–OCH3), 164.56 (С=О); 13C NMR (100 MHz,
CDCl3): 39.96 (C(O)СH2), 50.95 (CH2–CH=CH2), 55.53
(OCH3), 106.42 (CAr), 112.11 (CAr), 116.70 (CH2–CH=
CH2), 127.69 (CAr), 128.55 (CAr), 128.66 (CAr), 131.08
(CAr), 133.32 (CH2–CH=CH2), 135.45 (CAr), 136.93 (CAr),
157.53 (C=N), 163.14 (C–OCH3), 164.81 (С=О); anal.
calcd. for C19H18N2O2 (306.36): C, 74.49; H, 5.92; N, 9.14;
found: C, 74.68; H, 5.97; N, 9.03.
1-Allyl-8-methyl-4-phenyl-1H-benzo[b][1,4]diazepin-2
(3H)-one (30) Yield: method A, 1.28 g (88 %); m.p.
1
138–139 °C; IR (KBr) cm−1: 1670, 1620, 1600; H NMR
(500 MHz, DMSO-d6): 2.36 (s, 3H, CH3), 3.04 (d, 1H, J =
11.9, C(O)СH2), 4.14 (d, 1H, J = 11.9, C(O)СH2), 4.49 (q,
2H, J = 16.1, CH2–CH=CH2), 4.93 (d, 1H, J = 13.4,
CH2–CH=CH2), 5.02 (d, 1H, J = 13.8, CH2–CH=CH2), 5.73
(m, 1H, CH2–CH=CH2), 7.12 (d, 1H, J = 7.9, HAr), 7.29 (d,
1H, J = 7.8, HAr), 7.36 (s, 1H, HAr), 7.54 (d, 3H, J = 6.7,
HAr), 8.08 (d, 2H, J = 6.7, HAr); 13C NMR (125 MHz,
DMSO-d6): 20.76 (C–CH3), 39.68 (C(O)СH2), 48.93
(CH2–CH=CH2), 115.79 (CH2–CH=CH2), 122.37 (CAr),
126.24 (CAr), 126.72 (CAr), 127.55 (CAr), 128.73 (CAr),
131.08 (CAr), 133.42 (CAr), 133.63 (CH2–CH=CH2), 135.75
(CAr), 136.83 (C–CH3), 139.37 (CAr), 159.82 (C=N), 164.53
(С=О); anal. calcd. for C19H18N2O (290.37): C, 78.59; H,
6.25; N, 9.65; found: C, 78.82; H, 6.10; N, 9.58.
1-Methyl-7-nitro-4-phenyl-1H-benzo[b][1,4]diazepin-2
(3H)-one (31) Yield: method A, 1.21 g (82 %); m.p.
1
151–153 °C; IR (KBr) cm−1: 1685, 1635, 1600; H NMR

Med Chem Res
(500 MHz, DMSO-d6): 3.06 (d, 1H, J = 11.6, C(O)СH2),
3.37 (s, 3H, CH3), 4.21 (d, 1H, J = 11.8, C(O)СH2), 7.55
(m, 3H, HAr), 7.81 (d, 1H, J = 7.9, HAr), 8.15 (m, 4H, HAr);
anal. calcd. for C16H13N3O3 (295.30): C, 65.08; H, 4.44; N,
14.23; found: C, 65.21; H, 4.48; N, 14.28.
(dd, 1H, J = 17.0, 7.4, N+–CH2C≡CH), 2.92 (dd, 1H, J =
17.0, 7.4, N+–CH2C≡CH), 3.21 (m, 1H, N+–CH2C≡CH),
3.28 (m, 1H, N–CH2C≡CH), 4.74 (d, 1H, J = 17.8, C(O)
СH2), 4.80 (d, 1H, J = 17.8, C(O)СH2), 7.40–7.74 (m, 9H,
HAr); 13C NMR (125 MHz, DMSO-d6): 16.70 (N–
CH2C≡CH), 36.39 (C(O)СH2), 48.14 (N+–CH2C≡CH),
72.53 (N+–CH2C≡CH), 74.82 (N–CH2C≡CH), 79.31
(N–CH2C≡CH), 81.46 (N+–CH2C≡CH), 122.39 (CAr),
126.04 (CAr), 126.39 (CAr), 126.55 (CAr), 126.74 (CAr),
127.77 (CAr), 128.33 (CAr), 128.74 (CAr), 129.82 (CAr),
132.50 (CAr), 137.26 (CAr), 140.65 (CAr), 163.46 (C=N),
165.68 (С=О); anal. calcd. for C21H17BrN2O (393.28): C,
64.13; H, 4.36; N, 7.12; found: C, 64.35; H, 4.10; N, 7.45.
MS m/z: 313 (M+, cationic part of the salt).
1-Ethyl-7-nitro-4-phenyl-1H-benzo[b][1,4]diazepin-2(3H)-
one (32) Yield: method A, 1.22 g (79 %); m.p. 119–121 °C;
1
IR (KBr) cm−1: 1670, 1625, 1600; H NMR (300 MHz,
DMSO-d6): 1.06 (t, 3H, J = 6.8, CH2CH3), 3.13 (d, 1H, J =
11.0, C(O)СH2), 3.90 (d, 1H, J = 7.0, CH2CH3), 4.06 (d,
1H, J = 7.1, CH2CH3), 4.25 (d, 1H, J = 11.1, C(O)СH2),
7.60 (m, 3H, HAr), 7.83 (d, 1H, J = 7.8, HAr), 8.17 (m, 4H,
HAr); anal. calcd. for C17H15N3O3 (309.32): C, 66.01; H,
4.89; N, 13.58; found: C, 66.09; H, 4.98; N, 13.73.
1-Allyl-7-nitro-4-phenyl-1H-benzo[b][1,4]diazepin-2(3H)-
one (33) Yield: method A, 1.29 g (80 %); method B, 1.21
g (75 %); m.p. 141–143 °C; IR (KBr) cm−1: 1680, 1630,
Docking studies
Compounds 9–33 were subjected to docking studies against
human serum albumin (HSA). Ligand preparation: substance
structures were drawn using MarvinSketch 6.3.0 and saved in
mol format (MarvinSketch, http://www.chemaxon.com)]
Geometries were then optimized with HyperChem 8.0.8 using
molecular mechanics algorithm MM+ over 1000 cycles using
Polak-Ribiere (Conjugate Gradient) algorithm. The pre-
optimized structures were further refined using semi-
empirical (PM3) molecular modeling and saved as pdb
files. The pdb files were converted to PDBQT using
AutoDockTools-1.5.6, leaving the number of active torsions at
the default setting (Trott and Olson, 2010). Protein prepara-
tion: the PDB file (2BXF) was downloaded from the protein
data bank (http://www.pdb.org). Discovery Studio 4.0 was
used to delete water molecules and the ligand from the crystal
structure. The obtained protein structure was then saved as a
pdb file. Polar hydrogens were added using AutoDockTools-
1.5.6 and the structure was saved as a PDBQT file. Grid box
was set as the following: center_x = 53.967, center_y =
35.000, center_z = 74.155, size_x = 18, size_y = 18, size_z =
16. The docking was performed using Vina 1.1.2 (Sanner,
1999). The results were visualized using Discovery Studio 4.0.
1
1600; H NMR (500 MHz, DMSO-d6): 3.23 (d, 1H, J =
11.0, C(O)СH2), 4.29 (d, 1H, J = 11.0, C(O)СH2),
4.57 (s, 2H, CH2–CH=CH2), 5.00 (d, 1H, J = 17.3,
CH2–CH=CH2), 5.09 (d, 1H, J = 10.4, CH2–CH=CH2),
5.78 (m, 1H, CH2–CH=CH2), 7.59 (m, 3H, HAr), 7.76 (d,
1H, J = 9.1, HAr), 8.16 (m, 4H, HAr); 13C NMR (125 MHz,
DMSO-d6): 39.68 (C(O)СH2), 49.21 (CH2–CH=CH2),
116.49 (CH2–CH=CH2), 120.47 (CAr), 122.21 (CAr),
123.85 (CAr), 128.00 (CAr), 128.89 (CAr), 131.93 (CAr),
133.08 (CAr), 136.05 (CH2–CH=CH2), 139.03 (CAr),
141.50 (CAr), 143.72 (C–NO2), 162.92 (C=N), 164.46
(С=О); anal. calcd. for C18H15N3O3 (321.34): C, 67.28; H,
4.71; N, 13.08; found: C, 67.48; H, 4.80; N, 12.91.
4-Methyl-2-oxo-1,5-di(prop-2-yn-1-yl)-2,3-dihydro-1H-
benzo[b][1,4]diazepin-5-ium bromide (34) Yield: method
A, 0.91 g (55 %); semicrystalline solid; IR (KBr) cm−1:
1
3310, 2120, 1720, 1635; H NMR (500 MHz, DMSO-d6):
2.20 (s, 3H, CH3), 2.26 (m, 1H, N–CH2C≡CH), 2.87 (m,
4H, 2 × CH2C≡CH), 3.19 (m, 1H, N+–CH2C≡CH), 4.66
(m, 2H, C(O)СH2), 7.30 (m, 3H, HAr), 7.66 (m, 1H, HAr);
13C NMR (125 MHz, DMSO-d6): 15.77 (CH3), 22.07 (N–
CH2C≡CH), 36.17 (C(O)СH2), 48.84 (N+–CH2C≡CH),
72.59 (N+–CH2C≡CH), 74.69 (N–CH2C≡CH), 79.43
(N–CH2C≡CH), 82.02 (N+–CH2C≡CH), 122.10 (CAr),
125.68 (CAr), 125.78 (CAr), 125.91 (CAr), 132.32 (CAr),
140.62 (CAr), 164.28 (C=N), 165.49 (С=О); anal. calcd. for
C16H15BrN2O (331.21): C, 58.02; H, 4.57; N, 8.46; found:
C, 58.35; H, 4.29; N, 8.59. MS m/z: 251 (M+, cationic part
of the salt).
In silico PASS screening
PASS has been employed as a strong potential tool to
predict the biological activity spectrum of synthetic sub-
stances for the discovery of new drugs. PASS is based on
the SAR analysis of a training set containing more than
205,000 compounds exhibiting more than 3750 kinds of
biological activities (Goel et al., 2011). We performed vir-
tual screening of BDZs 9–33 using PASS online tool (http://
www.way2drug.com/PASSOnline) in order to select the
most promising anticonvulsant (main activity for Diazepam
according to PASS results) compounds for further in vivo
tests. The PASS software predicts the activities of a given
2-Oxo-4-phenyl-1,5-di(prop-2-yn-1-yl)-2,3-dihydro-1H-
benzo[b][1,4]diazepin-5-ium bromide (35) Yield: method
A, 1.28 g (65 %); m.p. 134–136 °C; IR (KBr) cm−1: 3300,
1
2120, 1720, 1630; H NMR (500 MHz, DMSO-d6): 2.12
(m, 1H, N–CH2C≡CH), 2.68 (m, 1H, N–CH2C≡CH), 2.75

Med Chem Res
compound as probable activity (Pa) and probable inactivity
(Pi). Being probabilities, the Pa and Pi vary from 0.000 to
1.000. In general, Pa + Pi ≠ 1, since these values are cal-
culated independently. Only activities with Pa 4 Pi are
considered promising for a particular compound.
Results and Discussion
Chemistry
A series of the starting benzodiazepine-2-ones 1–8 (1:
R2=Me, R3=R4=H; 2: R2=Me, R3=H, R4=Cl; 3: R2=Me,
R3=H, R4=Me; 4: R2=Ph, R3=R4=H; 5: R2=Ph, R3=H,
R4=Cl; 6: R2=Ph, R3=H, R4=OMe; 7: R2=Ph, R3=H,
R4=Me; 8: R2=Ph, R3=NO2, R4=H) was synthesized using
one-pot cyclocondensation of benzoylacetic and acetoacetic
esters with appropriate o-phenylenediamines (caution:
o-phenylenediamines are toxic and environmentally hazar-
dous). Three methods for the direct alkylation of com-
pounds 1–8 were then examined:
Method A: Reaction in benzene at 60 °C with 6 mol % of
a phase-transfer catalyst, TBAB, and an excess of aqueous
50 % NaOH.
Method B: Reaction in acetone with 5 equivalents of
solid KOH under reflux conditions.
Pharmacology
An approval of the Institutional Ethical Committee for Ani-
mal Experiments was obtained prior to performing the tests
below. The experiments were carried out in compliance with
the International Convention for the Protection of Vertebrate
Animals Used for Experimental and Other Scientific Pur-
poses (Strasbourg, 1985) as well as the Law of Ukraine “On
Protection of Animals from Inhumane Treatment”.
In vivo tests: the neurotropic (antihypoxic, tranquilizing
and anticonvulsant) activity and acute toxicity (LD50) of the
newly synthesized compounds 22 and 24 were studied
using white mice of both sexes, weighing 20–30 g. The
animals were housed in plastic cages with the stainless steel
top, had access to food and water ad libitum and were
contained at 21 2 °C with a 12-h light/dark cycle.
Humidity and ventilation were controlled according to
international standards.
Aqueous suspensions of the tested compounds 22 and 24
were prepared with the addition of TWEEN-80 and intro-
duced intraperitoneally 30 min prior to the testing. The same
volume of 0.8 % sodium chloride isotonic solution was
injected into the animals of the control group. The acute
toxicity was determined following intraperitoneal injection
of an investigated substance by establishing the lethal dose
(LD50) for 12 observations, according to the Prozorovskii’s
rapid method (Prozorovskii, 2007). The effect of a substance
injected in a dose of 1/10 LD50 was compared in groups of
12 animals. Neurotropic activity was estimated from: (a) the
influence on the lifetime of mice under hypoxic hypoxia
caused by placing the animals in a separate 125-ml chamber
without absorption of CO2; (b) the influence on the duration
of hexobarbital-induced anesthesia caused by a dose of 60
mg/kg; (c) the pentetrazol-induced spasms caused by an
intraperitoneal injection of 10 % aqueous pentetrazol solu-
tion in the dose of 150 mg/kg. Activity of the tested com-
pounds 22 and 24 was compared to that of a reference drug
Diazepam (oral LD50 for a mouse is 48 mg/kg (Peterson and
Talcott, 2013)) used in its standard dose of 1 mg/kg.
Method C: Reaction in dry DMF at 100 °C using 2
equivalents of NaH.
In all cases, good yields were obtained, ranging from 70
to 95 % (Scheme 1, Table 1). This allowed to produce
various N-alkyl-BDZs for subsequent in vivo tests in an
efficient manner under mild conditions. The reactions were
clean and complete within 1.5–3 h.
Our attempts to monoalkylate the substrates 1 and 4 with
propargyl bromide failed. Treatment of the starting materi-
als with excess of the alkylating agent (method A) gave
products identified as salts 34 and 35 (Scheme 2).
The structures of compounds 9–33 have been con-
1
firmed using IR, H, and 13C NMR spectroscopy as well
as elemental analysis. In the IR spectra, a characteristic
band at around 1600–1620 cm−1 indicates the presence of
the C=N bond of the seven-membered diazepine ring; a
sharp band at 1668–1690 cm−1 represents carbonyl group
1
stretching vibrations. The H NMR spectra of the BDZs
9–33 show characteristic signals for the non-equivalent
methylene protons of the seven-membered diazepine ring
as two doublets at 2.79–3.23 and 3.30–4.29 ppm
(2J 10.6–12.3 Hz), respectively. All the benzyl derivatives
12, 16, 19, 23, 26, and 29 also display two characteristic
doublets at 4.99–5.05 and 5.26–5.30 ppm (2J 15.9–16.1 Hz).
The structures of compounds 34 and 35 are consistent with
their NMR spectra and were further confirmed using mass
spectrometry.
In addition, the structure of the BDZ 27 possessing an
N-allyl substituent was studied in more detail using Corre-
lation Spectroscopy (COSY), Nuclear Overhauser Effect
Spectroscopy (NOESY), Heteronuclear Single-Quantum
Correlation spectroscopy (HSQC), and Heteronuclear
Multiple-Bond Correlation spectroscopy (HMBC) experi-
ments in DMSO-d6. The results are summarized in Fig. 2.
The antihypoxic, tranquilizing and anticonvulsant activ-
ities (NА) were estimated in the group of experimental
animals with respect to the control group and expressed
in percentage. The normalized values were calculated as
NА=(Ne/Nc)·100 %, where Nc and Ne are the mean values in
the control and experimental groups, respectively.
The experimental data were treated statistically by Student’s
test. Differences at p o 0.05 were considered significant.

Med Chem Res
Assignments of the 1H and 13C signals for all other products
were performed by analogy.
We have extracted X-ray diffraction structure of this com-
plex from Protein Data Bank (http://www.pdb.org) and used
it to study the binding of BDZs 9–33 to HSA.
Single crystals of the compound 29 were grown from
hexane solution and studied by X-ray diffraction (Fig. 3).
The seven-membered diazepine ring adopts a boat-like
conformation. The N(2), C(7), C(9), and N(1) atoms are
coplanar within 0.005 Å, whereas deviations of the C(1),
C(6), and C(8) atoms from the plane are − 0.73, − 0.72, and
− 0.77 Å, respectively. As the result, the H(5)…C(16) and
H(5)…C(17) come in close intramolecular contact (corre-
sponding distances are 2.56 and 2.59 Å as compared to the
sum of van der Waals radii being 2.87 Å (Zefirov, 1997)).
In the crystal phase, the C–H···π intermolecular hydrogen
bonds (C(18)–H(18)…C(10)′ (π) (0.5 − x, − 0.5 + y, 0.5 − z)
H…C 2.82 Å C–H…C 151° and C(8)–H(8a)…C(13)′ (π)
(−0.5 − x, − 0.5 + y, 0.5 − z) H…C 2.83 Å C–H…C 142°)
are observed.
The highest binding affinity was observed for compound
33 with binding energy of − 9.8 kcal/mol (Table 2), which is
comparable to that of the reference drug, diazepam
(−9.7 kcal/mol). Visualization of interactions for compound
33 is presented in Fig. 4. Four major hydrogen bonds with
HSA were identified: between LEU430 and the CO group
(3.29 Å), ASN391 and the unsubstituted nitrogen atom of
BDZ (3.25 Å), GLU450 and O of the nitro group (3.32 Å),
and PRO384 and O of the nitro group (3.77 Å) (Bissantz
et al., 2010; Pierce et al., 2002).
In silico PASS screening
PASS-predicted results for diazepam (reference drug) and
BDZs 9–33 are summarized in Table 2. The results for
basic neurotropic activities such as anticonvulsant, anti-
hypoxic, tranquilizing, and analgesic are given. In addi-
tion, we have also identified other important biological
activities with Pa (probability of activity) 4 0.7. The
tranquilizing potential of compounds 9–16 (R2=Me) is
significantly higher than that of their analogs 17–33
(R2=Ph). Compound 9 has the most promising predicted
activity (Pa 0.829). In general, antihypoxic action is
moderate for the two groups of BDZs 9–16 and 17–33, and
close to the value for diazepam (Pa 0.432). Analgesic
activity probabilities are equally very low for all com-
pounds, 9–33, and are characterized by Pa value within
0.208–0.300, which is significantly lower than that for
diazepam (Pa 0.748). The anticonvulsant activities of
BDZs 9–16 and 17–33 have similar predicted prob-
abilities. The best result was found for compound 22. In
silico screening of the synthesized BDZs also showed high
probability levels for the inhibition of amine/taurine
dehydrogenase, gluconate 2-dehydrogenase, and glyco-
sylphosphatidylinositol phospholipase D.
Molecular docking
HSA is an abundant plasma protein and one of the main
endogenous vehicles for biodistribution of molecules by
blood plasma. It has various physiological functions,
including the maintenance of osmotic pressure, transport,
distribution, and participation in the metabolism of many
endogenous and exogenous ligands (e.g., drugs, metabo-
lites, fatty acids, amino acids, and hormones). HSA
increases the solubility of ligands in blood plasma, which
can reduce their toxicity, and/or protect them against oxi-
dation or other reactions (Chaves et al., 2015; Taguchi et al.,
2012; Zsila et al., 2011). On the other hand, binding of
drugs by HSA restricts their free, active concentration. The
problem of overcoming the binding affinity for HSA
represents a major challenge in drug development.
Among all diversity of various BDZs represented in the
literature, we were able to find only one work devoted to
binding studies with HSA (Ghuman et al., 2005). The
authors isolated a corresponding complex with Diazepam.
Scheme 1 The synthesis of
target compounds 9–33
Scheme 2 The synthesis of
BDZ salts 34 and 35

Med Chem Res
Fig. 2 NMR chemical shifts and
important 2D correlations for the
compound 27 (DMSO-d6, ppm)
compounds 22 and 24 in white mice was found to be 687.5
88.6 and 658.0 76.0 mg/kg, respectively. Both
N-methyl BDZs showed significant tranquilizing activity of
4 400 % with respect to the control experiments. This
value is comparable to the activity of diazepam. The anti-
hypoxic activity of the new BDZs is higher than that of
diazepam by up to 1.34 times (for the chlorinated BDZ 22).
The anticonvulsant activity of the new BDZs is at the level
of 337–398 % with respect to the control experiments, but is
significantly lower than that of diazepam. This result is
generally consistent with PASS predictions. To our surprise,
the nature of the substituent at C-8 of the 1,5-BDZ core (Cl
for 22 and OMe for 24) does not affect the tranquilizing and
anticonvulsant activity, as was expected based on the PASS
data (Table 2). Thus, of the two compounds, the chlorine-
containing BDZ 22 is a better antihypoxic agent and the
BDZ 24 exhibits a stronger anticonvulsant effect. We
believe that the neurotropic agents we have discovered
could be possible drug candidates in the future. The
obtained experimental results are summarized in Table 3.
Fig. 3 Molecular structure of 1-benzyl-8-methyl-4-phenyl-1H-benzo
[b][1,4]diazepin-2(3H)-one 29 according to X-ray diffraction
Pharmacology
Conclusions
Based on the results of in silico screening, compound 22
was subjected to further in vivo testing. Our additional
interest to the derivative 22 was caused by its structural
isomerism to diazepam. For comparison with compound 22,
we also studied its analog 24. The BDZs 22 and 24 were
tested for in vivo toxicity, antihypoxic, tranquilizing, and
anticonvulsant properties. The intraperitoneal LD50 for
In this work, we have tested tree different one-pot methods
for the synthesis of N-alkyl-1,5-benzodiazepine-2-ones. We
found that all three are effective for the appropriate cases
and provide desired products within 70–95 % yield. The
products 13 and 21 are the first examples of N-(oxirane-2-
ylmethyl)-containing 1,5-BDZs. These compounds have
great synthetic potential with respect to further

Med Chem Res

Med Chem Res
Fig. 4 Interaction between
compound 33 (shown in red)
and HSA. Hydrogen bonds are
shown in black
Table 3 Neurotropic activity of BDZs 22 and 24
Compound
Antihypoxic activity
Tranquilizing activity
Anticonvulsant activity
Life span,
min
% to the control group
of animals
The duration
of sleep, min
% to the control group
of animals
Life span,
min
% to the control group
of animals
Control
16.4 0.9
24.4 1.7
16.2 0.6
32.3 0.3
16.0 0.7
25.0 1.2
148.8
19.9 3.1
83.2 11.8
19.9 3.1
81.9 10.2
15.0 1.9
61.8 17.7
418.1
4.3 1.5
2325.6
337.2
398.3
Diazepam
Control
100.0 10.6
4.3 1.5
199.4
156.3
411.6
412.0
Compound 22
Control
14.5 3.3
5.8 2.1
Compound 24
23.1 7.8
Acknowledgments This work was financially supported by the grant
of the President of Ukraine for young scientists, GP/F49/080 (super-
visor Dr. Vitaliy Palchikov). The authors are indebted to Dr. Oleksandr
Zhurakovskyi (University of Bristol, UK) for the thorough revision of
the manuscript.
transformations into various oxazaheterocycles (Kas’yan
et al., 2011a, b; Pal’chikov, 2013). In silico screening of the
synthesized compounds showed their high tranquilizing
and anticonvulsant potential coupled with strong proba-
bility levels of inhibition of amine dehydrogenase, taurine
dehydrogenase, gluconate 2-dehydrogenase, and glycosyl-
phosphatidylinositol phospholipase D. According to the
molecular docking studies, the highest binding affinity to
HSA was observed for compound 33 (−9.8 kcal/mol),
which is slightly better than for diazepam (−9.7 kcal/mol).
The two in vivo tested compounds 22 and 24 showed
high levels of antihypoxic, tranquilizing, and anticon-
vulsant activity compared to the reference drug diazepam.
The new compounds were characterized using IR, 1H NMR,
13C NMR, COSY, NOESY, HSQC, HMBC spectroscopy,
X-ray diffractometry, and elemental analysis techniques.
Compliance with ethical standards
Competing interest The author declares that they have no com-
peting interests.
References
Bissantz C, Kuhn B, Stahl MA (2010) Medicinal chemist’s guide to
molecular interactions. J Med Chem 53:5061–5084
Borges RS, Nagurniak GR, Queiroz LMD, Maia CSF, Barros CAL,
Orestes E, da Silva ABF (2016) Structure and toxicity of clozapine
and olanzapine on agranulocytosis. Med Chem Res 25:322–328

Med Chem Res
Caccia S, Ballabio M, Zanini MG, Garattini S, Samanin R (1982)
Antileptazol activity and kinetic of CP 1414 S (7-nitro-2-amino-
5-phenyl-3-H-,1,5-benzodiazepine-4-one) in the rat and mouse.
Eur J Drug Metab Pharmacokinet 7:93–97
Carli M, Ballabio M, Caccia S, Garattini S, Samanin R (1981) Studies
on some pharmacological activities of 7-nitro-2-amino-5-phenyl-
3H-1,5-benzodiazepine (CP 1414 S) in the rat. A comparison
with diazepam. Arzneimittel-Forschung 31:1721–1723
Chaves OA, Amorim APO, Castro LHE, Sant’Anna CMR, de Oliveira
MCC, Cesarin-Sobrinho D, Netto-Ferreira JC, Ferreira ABB (2015)
Fluorescence and docking studies of the interaction between human
serum albumin and pheophytin. Molecules 20:19526–19539
Chen X, Zheng Y, Shu C, Yuan W, Liu B, Zhang X (2011) Enan-
tioselective synthesis of 4-substituted 4,5-dihydro-1H-[1,5]ben-
Kas’yan LI, Pal’chikov VA, Bondarenko YaS (2011b) Five-membered
oxaza heterocyclic compounds on the basis of epoxides and
aziridines. Russ J Org Chem 47:797–841
Kruse H (1982) Clobazam: induction of hyperlocomotion in a new
nonautomatized device for measuring motor activity and
exploratory behavior in mice: Comparison with diazepam and
critical evaluation of the results with an automatized hole-board
apparatus (“Planche á Trous”). Drug Dev Res 2:145–151
Müller WE, Groh B, Bub O, Hofmann HP, Kreiskott H (1986)
In vitro and in vivo studies of the mechanism of action of
arfendazam, a novel 1,5-benzodiazepine. Pharmacopsychiatry
19:314–315
Nicholson AN, Stone BM, Clarke CH (1977) Effect of the 1,5-ben-
zodiazepines, clobazam and triflubazam, on sleep in man. Br J
Clin Pharmacol 4:567–572
zodiazepin-2(3H)-ones
by
the
Lewis
base-catalyzed
hydrosilylation. J Org Chem 76:9109–9115
Olkkola KT, Ahonen J (2008) Midazolam and other benzodiazepines.
Handb Exp Pharmacol 182:335–360
Page C, Michael C, Sutter M, Walker M, Hoffman BB (2002) Inte-
grated pharmacology, 2nd edn. Mosby, Edinburgh
Pal’chikov VA (2013) Morpholines. Synthesis and biological activity.
Russ J Org Chem 49:787–814
Pandeya SN, Rajput N (2012) Synthesis and anticonvulsant activity of
various mannich and schiff bases of 1,5-benzodiazepines. Int J
Med Chem 2012:237965, doi:10.1155/2012/237965
Peterson ME, Talcott PA (2013) Small animal toxicology, 3rd edn,
Elsevier, St Louis, MO, USA.
Pierce AC, Sandretto KL, Bemis GW (2002) Kinase inhibitors and the
case for CH…O hydrogen bonds in protein-ligand binding.
Proteins 49:567–576
Claremon DA, Frieidinger RM, Liverton N, Selnick HG, Smith GR
(1996) Preparation of novel N-(2-oxo-2,3,4,5-tetrahydro-1H-1,5-
benzodiazepin-3-yl)amides for the treatment of arrhythmia. PCT
Int. Appl. WO 9640656
Drummer OH (2009) Benzodiazepines. Wiley Encyclopedia of For-
ensic Science. Wiley, Chichester, UK.
El-Shafei AK, El-Kashef HS, El-Khawaga AM (1982) Synthesis of 2-
sybstituted 3-aryl / heteroaryl-2,3,3a,10-tetrahydro-4-methyl-pyr-
azolo[2,3-b][1,5]benzodiazepines. Indian J Chem 21B:655–657
Eltze M, Gonne S, Riedel R, Schlotke B, Schudt C, Simon WA (1985)
Pharmacological evidence for selective inhibition of gastric acid
secretion by telenzepine, a new antimuscarinic drug. Eur J
Pharmacol 112:211–224
Essassi EM, Salem M, Viallefont P (1987) Action de l’hydroxylamine
sur les dihydro-1,3-benzodiazepine-1,5-thiones(ones)-2. Bull Soc
Chim Fr (5):890–892.
Prozorovskii VB (2007) Statistical treatment of results of pharmaco-
logical studies. Psikhopharmakol Biol Narkol 7:2090–2120
Sanner MF (1999) Python: a programming language for software
integration and development. J Mol Graphics Mod 17:57–61
Sheldrick GM (2008) A short history of SHELX. Acta Crystallogr A
64:112–122
Solomko ZF, Sharbatyan PA, Gaponov AA, Avramenko VI (1990)
Synthesis and mass spectra of 2,3-dihydro-1H-1,5-benzodiaze-
pine-2-thiones. Chem Het Comp 26:341–345
Taguchi K, Chuang VTG, Maruyama T, Otagiri M (2012) Human
serum albumin—new insights on its structural dynamics, func-
tional impacts and pharmaceutical applications. J Pharm Sci
101:3033–3046
Trott O, Olson AJ (2010) AutoDock Vina: improving the speed and
accuracy of docking with a new scoring function, efficient opti-
mization and multithreading. J Comput Chem 31:455–461
Vernin D, Domloi H, Siv C, Metzger J, Archavlis A, Llinas JR (1980)
Alkylation en catalyse par transfert de phase de dihydro-1,3(2H)
benzo[2,3-b]diazepines-1,5-ones-2. anxiolytiques potentiels.
Chem Scr 16:157–162
Viviano M, Milite C, Rescigno D, Castellano S, Sbardella G (2015) A
continuous-flow synthesis of 1,4-benzodiazepin-5-ones, privi-
leged scaffolds for drug discovery. RSC Adv 5:1268–1273
Wang LZ, Li XQ, An YS (2015) 1,5-Benzodiazepine derivatives as
potential antimicrobial agents: design, synthesis, biological eva-
luation, and structure–activity relationships. Org Biomol Chem
13:5497–5509
Welsch ME, Snyder SA, Stockwell BR (2010) Privileged scaffolds for
library design and drug discovery. Curr Opin Chem Biol
14:347–361
Zefirov YuV (1997) ) Shortened intramolecular contacts and specific
interactions in molecular crystals. Cryst Rep (Kristallografiya)
42:936–958
Zsila F, Bikadi Z, Malik D, Hari P, Pechan I, Berces A, Hazai E (2011)
Evaluation of drug-human serum albumin binding interactions
with support vector machine aided online automated docking.
Bioinformatics 27:1806–1813
Fisher R, Blum D (1995) Clobazam, oxcarbazepine, tiagabine, topir-
amate, and other new antiepileptic drugs. Epilepsia 36:S105–S114
Gavai AV, Quesnelle C, Norris D, Han WC, Gill P, Shan W, Balog A,
Chen K, Tebben A, Rampulla R, Wu DR, Zhang Y, Mathur A,
White R, Rose A, Wang H, Yang Z, Ranasinghe A, D’Arienzo C,
Guarino V, Xiao L, Su C, Everlof G, Arora V, Shen DR, Cvijic
ME, Menard K, Wen ML, Meredith J, Trainor G, Lombardo LJ,
Olson R, Baran PS, Hunt JT, Vite GD, Fischer BS, Westhouse
RA, Lee FY (2015) Discovery of clinical candidate BMS-
906024: a potent pan-notch inhibitor for the treatment of leuke-
mia and solid tumors. ACS Med Chem Lett 6:523–527
Ghuman J, Zunszain PA, Petitpas I, Bhattacharya AA, Otagiri M,
Curry S (2005) Structural basis of the drug-binding specificity of
human serum albumin. J Mol Biol 353:38–52
Gilfillan L, Blair A, Morris BJ, Pratt JA, Schweiger L, Pimlott S,
Sutherland A (2013) Synthesis and biological evaluation of novel
2,3-dihydro-1H-1,5-benzodiazepin-2-ones; potential imaging
agents of the metabotropic glutamate 2 receptor. Med Chem
Commun 4:1118–1123
Goel RK, Singh D, Lagunin A, Poroikov V (2011) PASS-assisted
exploration of new therapeutic potential of natural products. Med
Chem Res 20:1509–1514
Hammer H, Ebert B, Jensen HS, Jensen AA (2015) Functional char-
acterization of the 1,5-benzodiazepine clobazam and its major
active metabolite N-desmethylclobazam at human GABAA recep-
tors expressed in Xenopus laevis oocytes. PLoS ONE 10:e0120239
Herpin TF, Van Kirk KG, Salvino JM, Yu ST, Labaudiniere RF
(2000) Synthesis of a 10000 Member 1,5-benzodiazepine-2-one
library by the directed sorting method. J Comb Chem 2:513–521
Hofmann HP, Ereiskott H, Kretzschmar R (1982) Anticonvulsant
properties of the novel 1,5-benzodiazepine Arfendazam. Naunyn-
Schmiedeberg’s Arch Pharmacol 321:R44
Kas’yan LI, Pal’chikov VA, Bondarenko YaS (2011a) Azacycloalkanes
from epoxides and aziridines. Russ J Org Chem 47:1609–1652