A click chemistry approach for the synthesis of cyclic ureido tethered coumarinyl and 1-aza coumarinyl 1,2,3-triazoles as inhibitors of Mycobacterium tuberculosis H37Rv and their in silico studies

Article abstract of DOI:10.1016/j.bmc.2019.115054

Nucleoside bases like uracil, pharmacophoric triazoles and benzimidazolones have been used during the present study to design molecular matrices for antitubercular activity, employing Click Chemistry. Click triazoles 4/7/10 have been obtained by the reaction of 4-(Azidomethyl)-2H-chromen-2-ones/quinolin-2(1H)-ones 3 and propargyl ethers 2/6/9 derived from theophylline/6-methyl uracil/2-benzimidazolone respectively. In addition to spectral data structures have been confirmed by single crystal X-ray diffraction studies in case of uracil bis alkyne (6) and theophylline mono triazole (4c). Theophylline linked mono triazoles, 4(a-d) and 6-methyl uracil linked bis triazoles, 7(a-e) have been found to inhibit Mycobacterium tuberculosis H37Rv with MIC values in the range 55.62–115.62 μM. Benzimidazolone bis triazoles, 10(a-n) showed better activity with MIC in the range 2.33–18.34 μM. Molecular modeling studies using Surflex-Dock algorithm supported our results.

Full text of DOI:10.1016/j.bmc.2019.115054

Bioorganic & Medicinal Chemistry xxx (xxxx) xxxx
Contents lists available at ScienceDirect
Bioorganic & Medicinal Chemistry
journal homepage: www.elsevier.com/locate/bmc
A click chemistry approach for the synthesis of cyclic ureido tethered
coumarinyl and 1-aza coumarinyl 1,2,3-triazoles as inhibitors of
Mycobacterium tuberculosis H37Rv and their in silico studies
a
a,⁎
b
c
Netravati Khanapurmath , Manohar V. Kulkarni , Shrinivas D. Joshi , G.N. Anil Kumar
b
a
Department of Studies in Chemistry, Karnatak University, Pavate Nagar, Dharwad 580003, Karnataka, India
Novel Drug Design and Discovery Laboratory, Department of Pharmaceutical Chemistry, S.E.T.’s College of Pharmacy, Sangolli Rayanna Nagar, Dharwad 580 002,
Karnataka, India
c
Department of Physics, M.S. Ramaiah Institute of Technology, MSRIT Post, MSR Nagar, Bangalore 560054, Karnataka, India
A R T I C L E I N F O
A B S T R A C T
Keywords:
Nucleoside bases like uracil, pharmacophoric triazoles and benzimidazolones have been used during the present
Click triazole
study to design molecular matrices for antitubercular activity, employing Click Chemistry. Click triazoles 4/7/
4
2
-(Azidomethyl)-2H-chromen-2-ones/quinolin-
(1H)-ones
1
0 have been obtained by the reaction of 4-(Azidomethyl)-2H-chromen-2-ones/quinolin-2(1H)-ones 3 and
propargyl ethers 2/6/9 derived from theophylline/6-methyl uracil/2-benzimidazolone respectively. In addition
to spectral data structures have been confirmed by single crystal X-ray diffraction studies in case of uracil bis
alkyne (6) and theophylline mono triazole (4c). Theophylline linked mono triazoles, 4(a-d) and 6-methyl uracil
linked bis triazoles, 7(a-e) have been found to inhibit Mycobacterium tuberculosis H37Rv with MIC values in the
range 55.62–115.62 μM. Benzimidazolone bis triazoles, 10(a-n) showed better activity with MIC in the range
Mycobacterium tuberculosis H37Rv
Surflex-Dock algorithm
2
.33–18.34 μM. Molecular modeling studies using Surflex-Dock algorithm supported our results.
1
. Introduction
Tuberculosis (TB) continues to be a disease with one of the highest
agents. Biodegradation of coumarins leads to in situ generation of car-
1
8
boxylic and phenolic –OH groups which facilitates penetration of
1
9
drugs through the bacterial cell wall. Potent anti-TB activity of tria-
zoles can be ascribed to their ability to inhibit mycobacterial growth by
blocking lipid biosynthesis and hydrogen bonding interaction at the
active site of enzymes viz. DprE1 (decaprenylphosphoryl-b-D-ribose-20-
epimerase) and InhA (NADH dependent trans enoyl-acyl-carrier-protein
mortality rates. World Health Organization (WHO) has estimated
1
0 million cases in 2017 around the world and 1.6 million deaths
1
among them. There is no decrease in the mortality rates despite the
availability of many clinically accepted drugs for the treatment of TB. A
unique feature of the fatal pathogen Mycobacterium tuberculosis (Mtb) is
its ability to combat TB drugs leading to multi drug resistant (MDR),
extensively drug resistant (XDR) and totally drug resistant (TDR) tu-
berculosis. Drug resistant TB requires a long-term treatment using a
combination of isoniazid, rifampicin, ethambutol and pyrazinamide. A
2
0
reductase), which enhances the bioavailability of the molecule.
Cyclic urea and ureides have been identified as pharmacophores in a
2
1–23
number of bioactive compounds.
Further, they have been reported
24
to exhibit a wide range of biological activities, such as antimicrobial,
2
5
26
27
28
antitubercular, antitumor, anti-HIV and antidiabetic. They have
2
–4
5–7
29
30
32
number of review and research articles have emphasized the need
for advanced therapeutic remedies and new drug regimens for TB.
Functionalized heterocycles have emerged as lead molecules in the
also been reported to be NK
1
antagonists, Chk
1
inhibitors and cal-
3
1
cium selective fluoroionophores. Coumarinyl theophylline (Fig. 1B)
3
3
and amidyl theophylline have been reported to exhibit promising
8
9
34,35
chemotherapy of tuberculosis. Heterocyclic moieties like quinolones,
anti-TB activity. Among the uracil derivatives
N-cyclopentenyl ur-
1
0
11
12
13
36
pyrroles, azoles, pyridines, and flavones have been combined to
obtain synergistic effects and have emerged as promising antitubercular
acil (Fig. 1C) inhibited the growth of Mtb at a higher concentration.
During last decade, a variety of nucleoside analogues have been re-
ported to target thymidylate synthase (ThyX), thymidine monopho-
sphate kinase (TMPKmt), adenosine kinase (ADK) and purine nucleo-
side phosphorylase which are the enzymes involved in nucleoside
1
4
agents with low MIC values. Use of coumarins and 1,2,3-triazoles in
17
1
5
16
combination with aryloxy,
alkylspacers
and benzimidazole
(
Fig. 1A) has emerged as a powerful approach in designing anti-TB
⁎
Corresponding author.
E-mail address: manohar274@gmail.com (M.V. Kulkarni).
https://doi.org/10.1016/j.bmc.2019.115054
Received 4 June 2019; Received in revised form 23 July 2019; Accepted 21 August 2019
0968-0896/ © 2019 Elsevier Ltd. All rights reserved.
Please cite this article as: Netravati Khanapurmath, et al., Bioorganic & Medicinal Chemistry, https://doi.org/10.1016/j.bmc.2019.115054

N. Khanapurmath, et al.
Bioorganic & Medicinal Chemistry xxx (xxxx) xxxx
Fig. 1. Present study related anti-tubercular agents.
3
7
salvage pathway. Nucleoside salvage pathway utilizes number of
enzymes, whose structural and functional features are different for Mtb
6-methyl uracil, 5. The required dipolar azides for CuAAC reaction were
obtained by a nucleophilic substitution reaction between sodium azide
3
8
42a
42b
1
compared to humans. N-triazinoindol-benzimidazol-2-ones were re-
and 4-(bromomethyl)-2H-chromen-2-ones /quinolin-2(1H)-ones
3
5,17
ported as Mtb inhibitors in which the cell wall enzyme RmlC (dTDP-6-
in acetone/DMF at room temperature according to earlier reports.
3
9
deoxy-D-xylo-4-hexulose 3′,5′-epimerase) was targeted (Fig. 1D). Pe-
netration of drugs through Mtb cell wall is very difficult since it is made
up of saturated long chain mycolic acids. Hence, targeting RmlC will be
a key factor in development of anti-TB drugs.
Cycloaddition reaction between dipolarophiles 2/6/9 and azides 3
was achieved using ascorbic acid and sodium carbonate along with
copper sulfate in catalytic amounts in DMF/water, 1:1 (v/v) under re-
4
3
flux conditions. CuAAC being a highly regioselective reaction af-
forded exclusively 1,4-disubstituted mono and bis-coumarinyl/1-aza
coumarinyl triazoles 4(a-d) and 7(a-e) of cyclic ureides (2 and 6 re-
spectively), whereas bis-coumarinyl/1-aza coumarinyl triazoles 10(a-n)
of cyclic urea (9) in highly pure form.
In view of our earlier reports on antitubercular activity of cou-
32
1
5,17,19
marinyl triazoles
and reports on corresponding theophyllines
39
as well as ability of benzimidazolones to inhibit enzyme RmlC, it was
thought of interest to design molecular hybrids with these pharmaco-
phoric moieties, to achieve a synergistic effect. Present paper is an ef-
fort towards development of such hybrids of coumarin, triazole, pyr-
imidines and benzimidazolones through Click Chemistry. Alkynes
derived from cyclic urea and ureides and azides derived from 4-bro-
momethyl coumarins/1-aza coumarins have been used to obtain cou-
marinyl mono/bis-1,2,3-triazoles of theophylline, uracil and benzimi-
dazolone (Fig. 2). Structurally, this set include three essential
pharmacophoric motifs, coumarin- ‘cell wall penetrators’, triazole-
Spectroscopic data of the synthesized triazoles 4(a-d), 7(a-e) and
10(a-n) confirmed their structures. Compound 4a (X = O, R = 6-CH ),
3
theophylline coumarinyl triazole exhibited three carbonyl stretching
−1
−1
−1
bands at 1652 cm , 1702 cm
and 1713 cm
in which first two
bands are of theophylline carbonyl groups and third one due to lactone
1
carbonyl stretching. H NMR of 4a (X = O, R = 6-CH
3
) showed singlets
at δ 8.26 and 8.24 ppm corresponding to C
theophylline respectively. C -H of coumarin resonated as a singlet at
5.74 ppm. Methylene protons linked to coumarin C and cyclic ureide
resonated as singlets at 5.93 and 5.60 ppm respectively. C -H and
-H of coumarin appeared as doublets with Jortho = 8.4 Hz at 7.47 and
.43 ppm respectively whereas C -H as a singlet at 7.61 ppm. Coumarin
protons resonated as a singlet at 2.35 ppm and two singlets at
5
-H of triazole and C
8
-H of
3
‘
stable and interactive motif’ and cyclic urea and ureides- ‘Mtb bio-
4
synthesis inhibitors’.
N
9
8
7
C
7
5
2
. Results and discussion
C
6
-CH
3
3
.20 and 3.41 ppm correspond to N-CH ’s protons. Further molecular
3
2.1. Chemistry
ion peak in EI-MS at 433 m/z (50%) supported above results. Finally,
the formation of cyclic theophylline mono-triazoles has been confirmed
by single crystal X-ray diffraction studies of 4c (CCDC No. 1911185).
Fig. 3 depicts ORTEP of 4c in which two molecules of 4c have stacked
one over the other.
Coumarin linked 1,2,3-triazoles developed via ‘Copper catalyzed
Azide Alkyne Cycloaddition reaction (CuAAC)’ have been reported from
1
5,17,19
our lab
and same synthetic strategy has been applied here with
few modifications. Dipolarophiles 2 and 9 have been synthesized by the
Compound 7a (X = O, R = 6-CH ), 6-methyl uracil bis-coumarinyl
3
reaction of theophylline and benzimidazol-2-one with propargyl bro-
−1
4
0,41
triazole also exhibited three carbonyl stretching bands at 1661 cm
,
mide according to earlier reports
(Schemes 1 and 3). Another di-
−1
−1
1
707 cm
and 1727 cm
in which first two bands are of uracil
polarophile 6-methyl uracil bis-propargyl, 6 has been synthesized from
1
moiety and third one due to lactone carbonyl stretching. H NMR of 7a
6
-methyl uracil and propargyl bromide using tetra-butyl ammonium
(
X = O, R = 6-CH
3
) showed singlets at δ 8.26 and 8.12 ppm corre-
bromide (TBAB) and potassium carbonate in DMF (Scheme 2). Spectral
sponding to C -H of both triazole rings. However C
5
5
-H of uracil
data and single crystal X-ray studies of 6 confirmed bis-N-alkylation of
2

N. Khanapurmath, et al.
Bioorganic & Medicinal Chemistry xxx (xxxx) xxxx
Fig. 2. Targeted Cyclic Ureido based coumarinyl-1,2,3-triazoles.
appeared as a singlet at 5.80 ppm. C
3
-H and C
5
-H of two coumarin rings
of compound 10a confirmed the formation of benzimidazol-2-one bis-
resonated as two pairs of singlets at 5.737–5.730 ppm and
coumarinyl triazole. All the signals of coumarin and triazole ring have
1
7
.65–7.64 ppm respectively. Methylene protons linked to coumarin C
and uracil /N also resonated as two pairs of singlets at
.92–5.89 ppm and 5.11–5.06 ppm respectively. C -H and C -H of
coumarin appeared as two pairs of doublets with J = 8.8 Hz at
.476–7.479 and 7.327–7.329 ppm respectively. C -CH protons of
coumarin resonated as two singlets at 2.37–2.36 ppm whereas singlet at
4
shown double integration in H NMR of 10a, which is due to symme-
N
1
3
,
trical nature of the molecule.
5
7
8
2.2. Mycobacterium tuberculosis H37Rv inhibition
7
6
3
All the synthesized compounds were tested for Mycobacterium tu-
2
.41 ppm corresponds to C
6
-CH protons of uracil moiety. Further
3
berculosis strain H37Rv inhibition using microplate Alamar Blue assay
molecular ion peak in EI-MS at 632 m/z (12%) for compound 7a con-
4
4
1
(MABA). Theophylline mono-triazole compounds, 4(a-d) and 6-me-
thyl uracil bis-triazole compounds, 7(a-e) have exhibited moderate in-
hibition of M. tuberculosis H37Rv, with minimum inhibitory con-
centration (MIC) in the range 55.62–115.62 µM (Table 1).
Benzimidazolone bis-triazoles, 10(a-n) have inhibited M. tuberculosis
H37Rv with MIC 2.35–18.34 µM (Table 1). Twelve compounds (10a,
10b, 10c, 10d, 10f, 10g, 10h, 10i, 10j, 10l, 10m and 10n) among
fourteen synthesized benzimidazolone bis-triazoles have shown MIC
values in the range 2.35–8.76 µM, which is less than that of Cipro-
floxacin, a standard drug used whose MIC was 9.43 µM. Compound 10k
was as active as Streptomycin (MIC = 10.74 µM). Compound 10e
showed considerable inhibition with MIC 18.25 µM less than that of
Pyrazinamide.
firmed the formation of uracil bis-coumarinyl triazole. H NMR of 7a
exhibited duplicates for all the signals excluding two signals at 2.41 and
5
.80 ppm, which is due to the unsymmetrical nature of the molecule.
Compound 10a (X = O, R = 6-CH ), benzimidazol-2-one bis-cou-
3
−1
marinyl triazole exhibited two carbonyl stretching bands at 1693 cm
−
1
1
and 1724 cm
due to cyclic urea and lactone carbonyl stretchings
) showed singlets at δ
-H of triazole and C -H of cou-
marin respectively. Methylene protons linked to coumarin C and
benzimidazol-2-one N /N resonated as singlets at 5.87 and 5.13 ppm
respectively. C -H and C -H of coumarin appeared as doublets with
J = 8.4 Hz at 7.43 and 7.29 ppm respectively whereas C -H as a singlet
at 7.57 ppm. Two doublet of doublets with J = 6 and 3.2 Hz at 7.15 and
.98 ppm correspond to aromatic protons of benzimidazol-2-one
moiety. Coumarin C -CH protons resonated as a singlet at 2.30 ppm.
Further (M+H) peak observed at 641 m/z (65%) in positive mode ESI
respectively. H NMR of 10a (X = O, R = 6-CH
3
8
.24 and 5.72 ppm corresponding to C
5
3
4
1
3
7
8
5
Lipophilicity of theophylline mono-triazoles, 4(a-d) and 6-methyl
uracil bis-trazoles, 7(a-c, e) (Clog P: −0.007 to 1.121) was sufficiently
lower than the benzimidazolone bis-triazoles, 10(a-n) (Clog P: 0.428 to
6
6
3
4
.482). Replacement of 6-methyl uracil with benzimidazolone,
Scheme 1. Synthesis of theophylline (cyclic ureide) coumarinyl triazoles.
3

N. Khanapurmath, et al.
Bioorganic & Medicinal Chemistry xxx (xxxx) xxxx
Scheme 2. Synthesis of 6-methyl uracil (cyclic ureide) bis-coumarinyl triazoles.
enhanced the lipophilicity of coumarinyl bis-triazoles, which in turn
increased Mtb H37Rv inhibition. However, lipophilicity of one of the
uracil bis-triazole, 7d (Clog P: 2.119) was as high as that of benzimi-
dazolone bis-triazoles 10(k-n) (Clog P: 0.428 to 2.148). Here, increase
in the lipophilicity of synthesized compound has not enhanced the
ability of the drug molecules to inhibit Mycobacterium tuberculosis
H37Rv. Further, molecular docking studies have been carried out to
rationalize their behavior (see Section 3, below).
further step was to examine their toxicity where Human Embryonic
kidney (HEK293) cells have been employed. From Table 1, tested
compounds exhibited moderate to low levels of cytotoxicity with IC50
values of the human embryonic kidney cells in the range of
943–12294 μM, and none of 23 compounds exhibited any significant
cytotoxic effects, suggesting huge potential for their in vivo use as anti-
TB agents. Theophylline mono-triazoles, 4(a-d) and 6-methyl uracil bis-
triazoles, 7(a-e) moderately inhibited HEK293 cell line with IC50 10 to
1
00 folds higher than the respective MIC values for Mtb H37Rv in-
2.3. Cytotoxicity and stability of the synthesized compounds
hibition. A second level of cytotoxicity was observed for benzimida-
zolone bis-triazoles with IC50 100–10000 folds higher than respective
Mtb H37Rv MIC values, which suggest that compounds 10a-10n can act
as new leads for the development of anti-TB drugs.
We have found a good number of active anti-TB compounds (10a,
1
0b, 10c, 10d, 10f, 10g, 10h, 10i, 10j, 10l, 10m and 10n) and the
Scheme 3. Synthesis of cyclic urea (benzimidazol-2-one) bis-coumarinyl triazoles.
4

N. Khanapurmath, et al.
Bioorganic & Medicinal Chemistry xxx (xxxx) xxxx
Fig. 3. ORTEP diagram of 4c (two molecules stacked).
Stability studies indicated that the samples were stable at room
temperature. There was no significant change in the pattern of ab-
sorption and emission spectra of the compounds when observed in DMF
and various buffers of pH 6–8 (supplementary Fig. S-1) over a period of
Table 1
Inhibition of Mycobacterium tuberculosis H37Rv by Theophylline, 6-methyl ur-
acil and benzimidazolone coumarinyl/1-aza coumarinyl mono and bis-triazoles,
4
(a-d), 7(a-e) and 10a-n and their cytotoxicity against the Human Embryonic
2
4 h. UV and fluorescence spectra of coumarinyl triazoles showed de-
kidney (HEK293) cells.
crease in intensity when observed after 72 h in buffers. However, two
characteristic absorption bands of coumarinyl triazoles around 290 and
Compounds
X
R
MIC (µM)
Clog Pa
Cytotoxicity
IC50 (µM)
3
20 nm and their emission bands45 were unaltered in all the cases.
4
4
4
4
7
7
7
7
7
1
1
1
1
1
1
1
1
1
1
1
1
1
1
a
O
6-CH
3
115.36
55.62
111.17
115.62
79.07
79.07
75.23
75.67
79.28
2.49
0.592
0.427
1.091
−0.007
1.121
1.121
0.789
2.119
−0.079
2.626
2.626
2.294
2.294
3.054
4.482
3.624
3.524
3.976
3.976
0.428
1.426
2.148
2.148
−0.676
−4.278
−1.146
1109.77
1376.65
ND
3
. In silico studies
b
O
6-OCH
3
c
O
5,7-CH
3
d
NH
O
8-CH
6-CH
7-CH
3
3
3
5041.90
1276.89
ND
3.1. Molecular modeling
a
b
O
Molecular modeling has been used to predict the binding interaction
of the compounds in the binding pocket of the enzymes. Molecular
c
O
6-OCH
3
3
1521.55
ND
d
O
5,7-CH
4
6
e
NH
O
8-CH
6-CH
7-CH
3
3
3
1152.60
3579.17
3521.42
4121.01
4617.55
ND
docking was carried out using Sybyl-X, version 2.0, running on Intel®
Core™ i3-2130 CPU@ 3.40 GHz processor using Windows 7 professional
workstation. Surflex-Dock algorithm of sybyl-X 2.0 was used to dock
designed compounds. The 3D crystal structures of enzymes Myco-
bacterium tuberculosis H37Rv InhA-D148G mutant (enoyl-[Acyl-Carrier-
Protein] reductase) in complex with NADH and RmlC (dTDP-6-deoxy-D-
xylo-4-hexulose 3′,5′-epimerase) with dTDP-rhamnose were down-
loaded from the Protein Data Bank with PDB entry codes 4DQU and
0a
0b
0c
0d
0e
0f
0g
0h
0i
0j
0k
0l
0m
0n
O
2.49
O
6-OCH
7-OCH
6-Cl
3
3
4.64
O
2.37
O
18.34
2.49
O
6-CH(CH
3
)
2
3197.70
943.47
3429.04
1133.42
3126.09
ND
O
5,7-CH
7,8-CH
3
3
2.39
O
2.39
O
5,6-benzo
7,8-benzo
H
8.76
2
IXC respectively and used for initial docking studies. Co-crystalized
O
2.34
NH
NH
NH
NH
–
10.23
2.50
ligands (co-factors) were removed from the downloaded structures,
water molecules were removed, essential H atoms were added, and side
chains were fixed during protein preparation. Gasteigere-Huckel
8-CH
6-Cl
7-Cl
–
3
4340.20
12294.15
4570.94
2.35
2.35
4
7
charges were calculated for the ligand, while Amber 7FF02 were used
for the protein. The model was then subjected to energy minimization
following the gradient termination of the Powell method for 3000
iterations using Tripos force field with non-bonding cut off set at 9.0
and the dielectric constant set at 4.0. The binding of the synthesized
compounds was also estimated using a variety of scoring functions that
have been compiled into the single consensus score (C-Score).
Pyrazinamide
Streptomycin
Ciprofloxacin
25.38
10.74
9.43
–
–
–
–
a
Clog P values obtained from Chem-Office 2004 software: ND – Not de-
termined.
5

N. Khanapurmath, et al.
Bioorganic & Medicinal Chemistry xxx (xxxx) xxxx
Fig. 4. Docked view of all the compounds at the active site of the enzymes PDB ID: 2IXC (A) and PDB ID: 4DQU (B).
3
.2. Docking studies
raised from second nitrogen of triazole ring with hydrogens of LYS165
and GLY96 (eN⋯HeLYS165, 2.74 Å; eN⋯HeGLY96, 2.74 Å), third
nitrogen of triazole ring showed two more bonding interactions with
hydrogens of LYS165 and GLY96 (eN⋯HeLYS165, 2.10 Å; eN⋯-
HeGLY96, 2.21 Å), oxygen of δ-lactone carbonyl group exhibited a
bonding interaction with hydrogen of TYR158 (eC]O⋯HeTYR158,
N-Triazinoindol-benzimidazolones have been found to inhibit RmlC
(
dTDP-6-deoxy-D-xylo-4-hexopyranosid-4-ulose 3,5-epimerase), a TB
38
cell wall biosynthetic enzyme. Since benzimidazolone bis-coumarinyl
triazoles exhibited excellent antitubercular activity against Mtb H37Rv,
RmlC was considered as target. Triazoles have been reported as in-
hibitors of InhA-D148G mutant, a NADH-dependent enoyl-[Acyl-Car-
1
.94 Å) and oxygen of cyclic urea carbonyl group also showed hydrogen
bonding interaction with hydrogen of GLY96 (eO⋯HeGLY96, 2.37 Å).
Compound 10m showed four hydrogen bonding interactions at the
active site of the enzyme (PDB ID: 4DQU), as depicted in supplementary
Fig. S-3(A-D).
7
rier-Protein] reductase and a study from our research group supports
1
5
bis-triazoles interaction with InhA-D148G mutant.
All the 23 inhibitors were docked into the active site of enzymes
XIC and 4DQU (Fig. 4). The predicted binding energies of the com-
As shown in Fig. 7B, compound 10h lies well within the enzyme
pocket. Fig. 8A indicates the superimposition of 2-benzimidazolone bis-
triazoles 10h and 10m with ligand, in which both the compounds were
found in plane with the ligand. However, less active theophylline
mono-triazole, 4d and uracil bis-triazole, 7e oriented out of the plane of
the ligand (Fig. 8B). And there were no H-bonding interactions from
triazoles of 7e, when observed at the active pocket of 4DQU (supple-
mentary Fig. S-4). Supplementary Fig. s-5(a-b) represent the hydro-
phobic and hydrophilic amino acids surrounded to the compounds 10h
and 10m.
2
pounds are listed in supplementary Table S-1 and Table S-2. The
comparative molecular docking study of synthesized compounds with
2
IXC and 4DQU ligand highlighted that the synthesized compounds
exhibited high C-score value. 2IXC ligand showed C-score value of 6.93,
whereas the twenty-one out of twenty-three compounds synthesized
have higher C-score values. Similarly, C-score value of 4DQU ligand
was found to be 7.75 whereas the twenty-one out of twenty-three
triazole compounds have higher C-score values. In view of the high C
score values and excellent activity exhibited by benzimidazolono-bis-
coumarinyl triazoles 10h, 10i, 10j and 10m were further studied in
detail for their binding interactions at the active site of the enzymes
PDB: 2IXC and 4DQU.
In silico studies reveal that benzimidazolone bis-coumarinyl triazoles
1
0(a-n), were the most active compounds in the present study which
inhibit InhA-D148G more efficiently than RmlC. Cyclic ureides (theo-
phylline and uracil) in 4d and 7e have tethered the molecules in a non-
interacting manner with 4DQU. A correlation between NADH (4DQU
ligand) and the highly active compounds 10h and 10m has been ob-
served. In turn, H-bonding interactions of triazole nitrogens emerged as
a key factor in the antitubercular activity.
Compound 10j with excellent anti-TB activity and highest C-score
value 9.97, showed five hydrogen bonding interactions at the active site
of 2IXC, as depicted in the Figs. 5(A-D). Among five interactions two
bonding interactions raised from 3rd nitrogen of triazole ring with
hydrogen of ARG59 (eN⋯HeARG59, 2.57 Å; 2.87 Å), 2nd nitrogen of
triazole ring makes a bonding interaction with hydrogen of ARG59
In the present study we have reported three types of triazoles con-
taining theophylline 4(a-d), 6-methyl uracil 7(a-e) and benzimidazo-
lone 10(a-n). Among the mono-triazoles 4(a-d), the 6-methoxy com-
pound (4b) with MIC of 55.62 µM was the most active compound
whereas, others were less active (Table 1). Uracil containing bis-tria-
zoles exhibited MIC values in the range of 75–79 µM and their activity
(
eN⋯HeARG59, 1.92 Å), 2nd nitrogen of another triazole ring makes a
bonding interaction with hydrogen of TYR138 (eN⋯HeTYR138,
.55 Å) and oxygen atom of carbonyl group present on the 2nd position
of coumarin ring makes a bonding interaction with hydrogen of LYS72
eC]O⋯HeLYS72, 2.04 Å). Compound 10i, regioisomer of 10j with
2
(
slightly low anti-TB activity have also shown five interactions at the
active site of enzyme 2IXC (supplementary Fig. S-2). As depicted in
Fig. 6(A) half part of the molecule 10i was outside the active pocket of
enzyme 2IXC and when docked view of 10i and 10j were superimposed
with that of 2IXC ligand, the difference in the orientation of ligand and
compounds 10i and 10j was clearly observed (Fig. 6A). However less
active theophylline mono-triazole, 4d and uracil bis-triazole, 7e were
oriented totally out of the plane of 2IXC ligand (Fig. 6B). The binding
interaction of 2IXC ligand at active site showed eight bonding inter-
actions and the docked view of the same has been depicted in supple-
mentary Fig. S-2, in which ligand lies within the active pocket of en-
zyme 2IXC.
was not sensitive to the groups like eCH
3
/eOCH . In the benzimida-
3
zolone containing bis-triazoles the activity has been found to be sensi-
tive to the groups attached to coumarin ring. Compounds 10a (R = 6-
CH
3
), 10b (R = 7-CH
3
) and 10d (R = 6-CH ) were most active com-
3
pounds in this series with MIC values of 2.49, 2.49 and 2.37 µM. In-
troduction of an additional eCH group as observed in 10g and 10h did
3
inspire the activity. Among benzo substituted 7,8-benzo compound
(10j) with MIC 2.34 µM was better inhibitor than the 5,6-benzo com-
pound (10i) with MIC 8.76 µM. Among the carbostyril compounds 10k-
10n (X = NH), 10l (R = 8-CH ), 10m (R = 6-Cl) and 10n (R = 7-Cl)
3
have MIC values of 2.50, 2.35 and 2.35 µM respectively, which shows
that chloro substituent in the carbostyril has enhanced the activity
compared to unsubstituted compound 10k whose MIC value is
10.23 µM (Table 1). SAR depicted in Fig. 9 indicating all these effects.
Compound 10h having excellent anti-TB activity, showed six hy-
drogen bonding interactions at the active site of 4DQU, as depicted in
the Figs. 7(A-D). Among six interactions two bonding interactions
6

N. Khanapurmath, et al.
Bioorganic & Medicinal Chemistry xxx (xxxx) xxxx
Fig. 5. Compound 10j inside the proposed binding pocket of the enzyme RmlC (A), Docked mode of compound 10j (B), 3D (C) and 2D (D) representation of docked
view of compound 10j at the active site of RmlC.
4
. Conclusion
uncorrected. IR spectra (KBr disc) were recorded on a Nicolet-5700 FT-
1 13
IR spectrophotometer. H and C NMR spectra were recorded on Jeol
From the present study it can be concluded that two triazole units
400 and 100 MHz spectrometer using CDCl
3
and DMSO‑d as solvents.
6
are necessary to achieve significant antitubercular activity as revealed
by benzimidazolone bis-triazoles 10(a-n) and most active compounds
were 10h and 10m. Docking studies substantiated this observation
which revealed an additional interaction of benzimidazolone oxygen.
Theophylline mono triazoles, 4(a-d) and bis triazoles from uracil, 7(a-e)
exhibited least and moderate activity respectively. Better activity of bis-
triazoles 10(a-n) is probably associated with the conformational flex-
ibility which is relatively better than compounds 7(a-e).
Chemical shifts are expressed in δ ppm. Mass spectra were recorded
using Agilent-single Quartz GCMS and Watets model-Synapt G2-LCMS.
Purity of the compound was checked by TLC. All the chemicals pur-
chased were of analytical grade and unless otherwise stated they were
used without further purification.
5
.1.1. Procedure for the synthesis of 1,3-dimethyl-7-(prop-2-ynyl)-1H-
purine-2,6(3H,7H)-dione (2)
Theophylline alkyne
2
was prepared according to literature
4
0
5
. Experimental section
method.
2 g of theophylline 1 (11.1 mM) and 1.9 g of K CO
2
3
(
14.4 mM) taken in 30 mL of DMF were stirred for 30 min at room
5.1. Chemistry
temperature. Then 1.68 mL of propargyl bromide (22.2 mM) added to
the reaction mixture and refluxed for 2 h. After completion of reaction
as monitored by TLC, the reaction mixture was quenched in ice water
Melting points were determined by open capillary method and are
Fig. 6. Superimposition of compounds 10i (Magenta colour) and 10j (Green colour) (A) and compounds 4a (Yellow colour) and 7a (Red colour) (B) with RmlC ligand
(
Blue colour). (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)
7

N. Khanapurmath, et al.
Bioorganic & Medicinal Chemistry xxx (xxxx) xxxx
(A)
(B)
(
C)
(D)
LYS165
2.10 Å
N
N
2.74 Å
N
O
Å
N
N
N
N
Å
1
.
2
N
7
2
3
H
3
C
.
2
2.74 Å
GLY96
CH
3
H
3
C
O
O
O
CH
3
O
1.94 Å
TYR158
Fig. 7. Compound 10h inside the proposed binding pocket of the enzyme InhAD148G (A), Docked mode of compound 10j (B), 3D (C) and 2D (D) representation of
docked view of compound 10h at the active site of InhA-D148G.
and the separated solid was filtered and dried. 2.1 g of off-white com-
indicated by TLC. Then the reaction mixture quenched in ice cold water
and extracted using ethyl acetate (15 mL × 3). 1.2 g of light yellow
compound 6 was obtained after evaporation of ethyl acetate under
pound 2 (M.P = 210–212 °C) was obtained and used for further reac-
−
1
tion without any purification. IR (KBr): cm
1651 and 1704 (theop
1
−1
C]O); H NMR (CDCl
3
, 400 MHz): δ ppm 7.83 (s, 1H, imid-H), 5.17 (d,
reduced pressure. White; Yield 84%; m.p: 124–126 °C; IR (KBr): cm
1
2
2
1
2
H, J = 2.0 Hz, alkyne-CH
.60 (t, 1H, J = 2.0 Hz, alkyne-CH); C NMR (CDCl
55.26, 149.12, 140.44, 133.74, 117.08, 76.56, 76.11, 36.47, 29.83,
8.00; MS (EI) m/z: Calcd. for C10 -218.0804; Found: 218
].
2
), 3.60 (s, 3H, eCH
3
), 3.41 (s, 3H, eCH
3
),
1652 and 1702 (C]O), 2218 (C^C); H NMR (CDCl
3
, 400 MHz): δ ppm
1
3
3
, 100 MHz): δ ppm
5.68 (s, 1H, alkene-CH), 4.71 and 4.69 (d, 2H, J = 2 Hz, -alkyne-CH ),
2
13
2.39 (s, 3H, eCH
3
) 2.36 and 2.17 (t, 1H, J = 2 Hz, alkyne-CH);
C
H
10
4
N O
2
NMR (CDCl , 100 MHz): δ ppm 160.86, 151.31, 151.06, 102.14, 78.01,
3
+%
[
M
77.20, 73.40, 70.70, 34.18, 30.58, 19.51; EI-MS: MS (EI) m/z: Calcd. for
-202.0742; Found: 202 [M+ −100%].
%
C
11
H
10
N
2
O
2
5
.1.2. Procedure for the synthesis of 6-methyl-1,3-di(prop-2-ynyl)
pyrimidine-2,4(1H,3H)-dione (6)
5.1.3. Procedure for the synthesis of substituted 1,3-Bis(prop-2-ynyl)-1H-
1,3-benzimidazol-2(3H)-one (9)
To a stirred solution of 1 g of 6-methyl uracil 5 (7.9 mM), 2.32 g of
potassium carbonate (16.2 mM) and 0.53 g of tetra-n-butyl ammonium
bromide (1.05 mM) in 40 mL of DMF was added 1.42 mL of propargyl
bromide (16.2 mM) drop wise. Reaction mixture was stirred at room
temperature for about 12–14 h till the completion of reaction as
Benzimidazolone bis-alkyne 9 was prepared according to literature
4
1
method. To a mixture of 0.5 g of 1H-benzimidazol-2(3H)-one 8
(3.75 mM), 1.125 g of potassium carbonate (8 mM) and 0.25 g of tetra-
n-butyl ammonium bromide (0.5 mM) in 30 mL of DMF was added
Fig. 8. Superimposition of compounds (A) 10h (Green) and 10m (Purple) and (B) 4d (Purple) and 7e (Green) with 4DQU ligand (Red orange). (For interpretation of
the references to color in this figure legend, the reader is referred to the web version of this article.)
8

N. Khanapurmath, et al.
Bioorganic & Medicinal Chemistry xxx (xxxx) xxxx
Fig. 9. Structure Activity Relationship of coumarinyl cyclic urea and ureide triazoles.
0
.7 mL of propargyl bromide (8 mM). Stirring was continued at room
159.91, 154.96, 151.84, 151.64, 150.17, 149.08, 143.57, 143.05,
134.40, 124.86, 123.88, 117.39, 114.54, 114.50, 106.52, 103.98,
temperature for 6 h. The salt was removed by filtration and the filtrate
concentrated under reduced pressure. The product was purified by re-
49.73, 41.83, 27.74, 25.03, 20.80; MS (EI) m/z: Calcd. for C21
H
19
N O -
7 4
433.1499; Found: 433 [M+ ].
%
crystallization from dichloromethane to give white crystals of 9
1
(
M.P = 152 °C). H NMR (CDCl
3
, 400 MHz): δ ppm 7.22–7.15 (m, 4H,
Ar-H), 4.69 (d, 4H, J = 2.4 Hz, alkyne-CH
2
), 2.29 (t, 2H, J = 2.0 Hz,
5
.1.5.1. 7-((1-((6-Methoxy-2-oxo-2H-chromen-4-yl)methyl)-1H-1,2,3-
1
3
alkyne-CH);
C NMR (CDCl
3
, 100 MHz): δ ppm 152.98, 128.46,
triazol-4-yl)methyl)-1,3-dimethyl-1H-purine-2,6(3H,7H)-dione (4b). Pale
1
21.97, 108.60, 76.89, 72.84, 30.62.
−1
green; Yield 81%; m.p: 177–179 °C; IR (KBr): cm
1645 and 1701
NMR (DMSO‑d
1
(
cyclic ureide C]O),1715 (lactone C]O);
H
6
,
5
.1.4. General procedure for the synthesis of 4-(4azidomethyl)-2H-
400 MHz): δ ppm 8.23 (s, 1H, Tri-H), 8.19 (s, 1H, cyclic ureide-H),
7.35–7.19 (m, 3H, Cou-C8,7,5-H’s), 5.91 (s, 2H, Cou-C -CH ), 5.79 (s,
1H, Cou-C -H), 5.55 (s, 2H, cyclic ureide-N -CH ), 3.72 (s, 3H, eOCH ),
, 100 MHz):
15,17
chromen-2-ones/quinolin-2(1H)-ones
(3)
4
2
4
2a
The required 4-(bromomethyl)-2H-chromen-2-ones
were ob-
3
9
2
3
1
3
tained by the Pechmann cyclization of substituted phenols with ethyl 4-
42b
3.36 (s, 3H, eCH
3
), 3.14 (s, 3H, eCH
3
); C NMR (DMSO‑d
6
4
8
bromoacetoacetate whereas 4-(bromomethyl)quinolin-2(1H)-ones
were obtained by a thermal condensation of substituted anilines with
δ ppm 160.01, 156.10, 154.79, 151.51, 150.28, 148.96, 147.86,
143.18, 125.52, 120.17, 123.88, 118.36, 117.97, 114.72, 108.07,
ethylacetoacate followed by bromination and cyclisation using H
2 4
SO .
106.31, 56.29, 49.84, 41.82, 29.96, 28.04; MS (EI) m/z:Calcd. for
%
Thus prepared 4-(bromomethyl)-2H-chromen-2-ones/quinolin-2(1H)-
ones(0.01 M equiv) were taken in 20 mL of acetone/DMF in a round-
bottom flask. To that, sodium azide (0.012 M equiv) in 3 mL of water
was added drop wise with stirring, which was continued for 10 h (re-
action was monitored by TLC). The reaction mixture was then poured
into ice cold water. Separated solid was filtered, recrystallized using
ethanol and melting points compared with the literature reports.1
C
21
H
19
N
7
O
5
-449.1448; Found: 449 [M+ ].
5.1.5.2. 7-((1-((5,7-Dimethyl-2-oxo-2H-chromen-4-yl)methyl)-1H-1,2,3-
triazol-4-yl)methyl)-1,3-dimethyl-1H-purine-2,6(3H,7H)-dione (4c). Pale
−
1
yellow; Yield 84%; m.p: 197–199 °C; IR (KBr): cm
1650 and 1698
1
(cyclic ureide C]O), 1717 (lactone C]O); H NMR (DMSO‑d ,
6
5,17
400 MHz): δ ppm 8.22 (s, 1H, Tri-H), 8.14 (s, 1H, cyclic ureide-H),
7
.08 (s, 1H, Cou-C
8
-H), 7.01 (s, 1H, Cou-C
6
-H), 6.01 (s, 2H, Cou-C -
4
CH
2
), 5.59 (s, 2H, cyclic ureide-N
), 3.15 (s, 3H, eCH
9
-CH
2
), 4.49 (s, 1H, Cou-C
3
-H), 3.37
5
.1.5. Synthesis of 1,3-dimethyl-7-((1-((6-methyl-2-oxo-2H-chromen-4-yl)
methyl)-1H-1,2,3-triazol-4-yl)methyl)-1H-purine-2,6(3H,7H)-dione (4a)
To a solution of compound 2 (1.0 mM) in DMF/H O, 1:1 (v/v),
CuSO ·5H O (0.15 mM), sodium carbonate (0.30 mM) and ascorbic acid
(
s, 3H, eCH
3
3
), 2.64 (s, 3H, eCH
3
), 2.31 (s, 3H,
1
3
eCH
3
); C NMR (DMSO‑d , 100 MHz): δ ppm 159.60, 155.01, 154.81,
6
2
1
1
2
4
53.83, 151.53, 148.99, 143.74, 143.21, 143.05, 137.07, 130.33,
4
2
25.69, 116.05, 114.96, 111.57, 106.33, 52.67, 41.85, 29.98, 28.07,
(
0.30 mM) were added. The mixture was stirred at room temperature
3.94, 21.16; MS (EI) m/z: Calcd. for C22
H
21
N
7
O -447.1655; Found:
4
for 30 min, 6-methyl-4-azidomethyl coumarin 3a (1.0 mM) were added,
and the resulting reaction mixture was refluxed on oil bath until the
starting material was consumed completely (monitored by TLC). Then
the reaction mixture was cooled, separated solid was filtered and wa-
shed with water and recrystallized from ethanol/dioxane (1:1) mixture.
+
%
47 [M ].
5.1.5.3. 1,3-Dimethyl-7-((1-((8-methyl-2-oxo-1,2-dihydroquinolin-4-yl)
methyl)-1H-1,2,3-triazol-4-yl)methyl)-1H-purine-2,6(3H,7H)-dione
−
1
−1
White; yield 84%; m.p: 150–152 °C; IR (KBr): cm
1652 and 1702
(4d). Pale yellow; Yield 80%; m.p: 206–208 °C; IR (KBr): cm
1652
1
1
(
cyclic ureide C]O), 1713 (lactone C]O); H NMR (DMSO‑d
6
,
(cyclic ureide C]O), 1698 (cyclic ureide and lactam C]O); H NMR
(DMSO‑d , 400 MHz): δ ppm 10.70 (s, 1H, eNH), 8.15 (s, 1H, Tri-H),
8.12 (s, 1H, cyclic ureide-H), 7.59 (d, 1H, Cou-C -H), 7.34 (d, 1H, Cou-
-H), 7.06 (d, 1H, Cou-C -H), 5.84 (d, 2H, Cou-C -CH ), 5.92 (s, 1H,
Cou-C -H), 5.55 (s, 2H, cyclic ureide-N -CH ), 3.38 (s, 3H, eCH ), 3.17
(s, 3H, eCH ), 2.38 (s, 3H, eCH ); MS (ESI) m/z: Calcd. for
4
00 MHz): δ ppm 8.26 (s, 1H, Tri-H), 8.24 (s, 1H, cyclic ureide -H), 7.61
s, 1H, Cou-C -H), 7.47 (d, 1H, J = 8.4 Hz, Cou-C -H), 7.43 (d, 1H,
J = 8.4 Hz, Cou-C -H), 5.93 (s, 2H, Cou-C -CH ), 5.74 (s, 1H, Cou-C
H), 5.60 (s, 2H, cyclic ureide-N -CH ), 3.41 (s, 3H, eCH ), 3.20 (s, 3H,
); C NMR (DMSO‑d , 100 MHz): δ ppm
6
(
5
7
5
8
4
2
3
-
C
7
6
4
2
9
2
3
3
9
2
3
1
3
eCH
3
), 2.44 (s, 3H, eCH
3
6
3
3
9

N. Khanapurmath, et al.
Bioorganic & Medicinal Chemistry xxx (xxxx) xxxx
-432.1652; Found: 433.0109 [M+H+ ].
%
52.56, 23.92, 21.17, 19.95; MS (ES) m/z: Calcd. for C35
H
C
21
H
20
N
8
O
3
32
N
8 6
O -
%
6
60.2445; Found: 660 [M+ ].
5
.1.6. Synthesis of 6-methyl-1,3-bis((1-((6-methyl-2-oxo-2H-chromen-4-
yl)methyl)-1H-1,2,3-triazol-4-yl)methyl)pyrimidine-2,4(1H,3H)-dione
7a)
To a stirred solution of cyclic ureide bis-alkyne 6 (0.5 mM) in DMF/
5.1.6.4. 1,3-Bis((1-((8-methyl-2-oxo-1,2-dihydroquinolin-4-yl)methyl)-
1H-1,2,3-triazol-4-yl)methyl)-6-methylpyrimidine-2,4(1H,3H)-dione
(
−
1
(7e). Pale green; yield 80%; m.p: 286–288 °C; IR (KBr) cm 1680 (br,
1
H
2
O, 1:1 (v/v), CuSO
4
·5H
2
O (0.15 mM), sodium carbonate (0.30 mM)
cyclic ureide and lactam C]O), 1707 (cyclic ureide C]O); H NMR
and ascorbic acid (0.30 mM) were added. The mixture was stirred at
(DMSO‑d , 400 MHz): δ ppm 10.71 (s, 2H, eNH), 8.17 and 7.99 (2s, 2H,
6
room temperature for 20 min, 6-methyl-4-azidomethyl coumarin 3a
Tri-H’s), 7.62 and 7.61 (2d, 2H, J = 7.2 Hz, 1-Aza Cou-C
2H, J = 7.2 Hz,1-Aza Cou-C H’s), 7.07 (t, 2H, J = 7.2 Hz, 1-Aza Cou-
H’s), 5.88 and 5.86 (2s, 2H, 1-Aza Cou-C -H’s Cou-C -CH ’s), 5.85
and 5.81 (2s, 4H, 1-Aza Cou-C -CH ’s), 5.66 (s, 1H, cyclic ureide-H),
5
H’s), 7.32 (d,
(
1.0 mM) were added, and the resulting reaction mixture was refluxed
7
on oil bath until the starting material was consumed completely
monitored by TLC). Then the reaction mixture was cooled, separated
C
6
3
4
2
(
4
2
solid was filtered and washed with water and recrystallized from DMF.
5.07 and 5.02 (2s, 4H, cyclic ureide-N
1
& N
3
-CH
2
’s), 2.38 (s, 3H, eCH
3
),
−
1
White; Yield 87%; m.p: 230–232 °C; IR (KBr) cm 1661 and 1707
2.36 (s, 6H, eCH
3
); MS (ESI+) m/z: Calcd. for C33
H
30
N
10 4
O
-630.2451;
1
+%
(
cyclic ureide C]O), 1727 (lactone C]O); H NMR (DMSO‑d
6
,
Found: 631.3227[M+H ].
4
00 MHz): δ ppm 8.26 and 8.12 (2s, 2H, Tri-H’s), 7.65 and 7.64 (2s, 2H,
-H’s), 7.48 and 7.46 (2d, 2H, J = 8.4 Hz, Cou-C -H’s), 7.33 and
-H’s), 5.92 and 5.89 (2s, 4H, Cou-C
’s), 5.80 (s, 1H, cyclic ureide-H), 5.73 (2s, 2H, Cou-C -H’s), 5.11
& N -CH ’s), 2.41 (s, 3H, eCH ), 2.37
); C NMR (DMSO‑d , 100 MHz): δ ppm
61.47, 160.06, 153.66, 151.69, 150. 37, 150.49, 134.39, 133.90,
25.54, 124.98, 117.29, 117.08, 114.21, 113.98, 101.03, 49.64, 49.51,
0.96, 19.93; MS (EI) m/z: Calcd. for C33 -632.2132; Found:632
].
Cou-C
5
7
5.1.7. Synthesis of 1,3-bis((1-((6-methyl-2-oxo-2H-chromen-4-yl)methyl)-
7
.31 (2d, 2H, J = 8.4 Hz, Cou-C
8
4
-
1H-1,2,3-triazol-4-yl)methyl)-1H-benzo[d]imidazol-2(3H)-one (10a)
CH
2
3
To a solution of compound 9 (0.5 mM) in DMF/H O, 1:1 (v/v),
2
and 5.06 (2s, 4H, cyclic ureide-N
1
3
2
3
CuSO
4
·5H O (0.15 mM), sodium carbonate (0.30 mM) and ascorbic acid
2
1
3
and 2.36 (2s, 6H, eCH
3
6
(0.30 mM) were added. The mixture was stirred at room temperature
for 30 min, 6-methyl-4-azidomethyl coumarin 3a (1.0 mM) were added,
and the resulting reaction mixture was refluxed on oil bath until the
starting material was consumed completely (monitored by TLC). Then
the reaction mixture was cooled, separated solid was filtered and wa-
shed with water and recrystallized from DMF. White; yield 81%; m.p:
1
1
2
H
28
N
8 6
O
+%
[
M
−1
5
.1.6.1. 1,3-Bis((1-((7-methyl-2-oxo-2H-chromen-4-yl)methyl)-1H-1,2,3-
240–242 °C; IR (KBr) cm 1693 (cyclic urea C]O), 1724 (lactone C]
1
triazol-4-yl)methyl)-6-methylpyrimidine-2,4(1H,3H)-dione (7b). White;
O); H NMR (DMSO‑d
6
, 400 MHz): δ ppm 8.24 (s, 2H, Tri-H’s), 7.57 (s,
−
1
Yield 84%; m.p: 277–279 °C; IR (KBr) cm
1670 and 1709 (cyclic
, 400 MHz): δ
2H, Cou-C
J = 8.4 Hz, Cou-C
H), 6.98 (dd, 2H, J = 6 and 3.2 Hz, cyclic urea Ar-H), 5.87 (s, 4H, Cou-
-CH ’s), 5.72 (s, 2H, Cou-C -H’s), 5.13 (s, 4H, cyclic urea-N & N
CH , 100 MHz): δ ppm
5
-H), 7.43 (d, 2H, J = 8.4 Hz, Cou-C
7
-H), 7.29 (d, 2H,
1
ureide C]O), 1731 (lactone C]O); H NMR (DMSO‑d
6
8
-H), 7.15 (dd, 2H, J = 6 and 3.2 Hz, cyclic urea Ar-
ppm 8.18 and 8.04 (2s, 2H, Tri-H’s), 7.67 and 7.66 (2d, 2H, J = 8.0 Hz,
Cou-C
5
-H’s), 7.20–7.16 (m, 4H, Cou-C
-CH ’s), 5.76 (s, 1H, cyclic ureide-H), 5.71 and 5.66 (2s, 2H,
-H’s), 5.07 and 5.02 (2s, 4H, cyclic ureide-N & N -CH ’s), 2.37
); C NMR (DMSO‑d , 100 MHz): δ
6
and C
8
-H’s), 5.85 and 5.82 (2s,
C
4
2
3
1
3
-
1
3
4
H, Cou-C
4
2
2
’s), 2.30 (s, 6H, eCH
3
); C NMR (DMSO‑d
6
Cou-C
3
1
3
2
160.03, 153.43, 151.71, 150.54, 143.50, 134.39, 133.91, 129.17,
125.26, 124.96, 121.68, 117.28, 117.09, 114.19, 108.95, 49.62, 36.39,
1
3
(
s, 3H, eCH
3
), 2.36 (s, 6H, eCH
3
6
ppm 161.42, 160.04, 153.74, 153.53, 151. 98, 150.58, 150.35, 144.01,
20.94; MS (ESI+) m/z: Calcd. for C35
H
28
N
8
O -640.2181; Found:
5
1
2
6
26.21, 124.95, 117.39, 117.18, 115.24, 109.29, 106.42, 49.72, 49.61,
1.65, 21.57; MS (EI) m/z: Calcd. for C33 -632.2132; Found:
32 [M ].
641.4010 [M+H+ ].
%
H
28
N
O
8 6
+
%
5.1.7.1. 1,3-Bis((1-((7-methyl-2-oxo-2H-chromen-4-yl)methyl)-1H-1,2,3-
triazol-4-yl)methyl)-1H-benzo[d]imidazol-2(3H)-one (10b). White; yield
−
1
5
.1.6.2. 1,3-Bis((1-((6-methoxy-2-oxo-2H-chromen-4-yl)methyl)-1H-
,2,3-triazol-4-yl)methyl)-6-methylpyrimidine-2,4(1H,3H)-dione
87%; m.p: 270–272 °C; IR (KBr) cm
1698 (cyclic urea C]O), 1727
1
1
(lactone C]O); H NMR (DMSO‑d
6
, 400 MHz): δ ppm 8.23 (s, 2H, Tri-
-H), 7.24 (d, 2H, J = 8.4 Hz, Cou-
−
1
(
7c). Green; Yield 87%; m.p: 250–252 °C; IR (KBr) cm 1668 and
H’s), 7.67 (d, 2H, J = 8.4 Hz, Cou-C
-H), 7.18 (s, 2H, Cou-C
5.88 (s, 4H, Cou-C -CH
5
1
1
4
714 (cyclic ureide C]O), 1734 (lactone C]O); H NMR (DMSO‑d
6
,
C
6
8
-H), 7.16–7.00 (m, 4H, cyclic urea Ar-H),
00 MHz): δ ppm 8.23 and 8.10 (2s, 2H, Tri-H’s), 7.34 and 7.33 (2s, 2H,
-H’s), 7.248 and 7.241 (2s, 2H, Cou-C -H’s), 7.22
-H’s), 5.90 and 5.87 (2s, 4H, Cou-
’s), 5.85 and 5.80 (2s, 2H, Cou-C -H’s), 5.69 (s, 1H, cyclic
& N -CH ’s), 3.75 (s,
, 100 MHz): δ ppm
4
2
’s), 5.79 (s, 2H, Cou-C
3
);
-H’s), 5.15 (s, 4H, cyclic
1
3
J = 8.8 Hz, Cou-C
8
5
urea-N
1
& N
3
-CH
2
’s), 2.41 (s, 6H, eCH
3
C NMR (DMSO‑d ,
6
and 7.21 (2d, 2H, J = 8.8 Hz, Cou-C
7
100 MHz): δ ppm 160.01, 153.76, 153.55, 150.37, 144.00, 143.50,
C
4
-CH
2
3
135.19, 132.47, 129.29, 126.19, 124.98, 115.23, 113.45, 108.84,
ureide-H), 5.06 and 5.01 (2s, 4H, cyclic ureide-N
1
3
2
108.55, 49.77, 36.52, 21.71; MS (EI) m/z: Calcd. for C35
H
28
N O -
8 5
1
3
+%
6
1
1
4
H, eOCH
3
), 2.37 (s, 3H, eCH
3
); C NMR (DMSO‑d
6
640.2181; [M ]not found.
61.46, 160.07, 156.11, 153.65, 150.36, 150.13, 147.89, 125.50,
25.14, 120.18, 118.39, 118.04, 114.92, 108.19, 101.03, 56.31,
5.1.7.2. 1,3-Bis((1-((6-methoxy-2-oxo-2H-chromen-4-yl)methyl)-1H-
9.82, 49.70, 19.37; MS (ES) m/z: Calcd. for C33
H
28
N
8
O
8
-664.2030;
1,2,3-triazol-4-yl)methyl)-1H-benzo[d]imidazol-2(3H)-one (10c). Light
+
%
−1
Found: 664 [M ].
green; yield 89%; m.p: 261–262 °C; IR (KBr) cm
1691 (cyclic urea
1
C]O), 1711 (lactone C]O); H NMR (DMSO‑d
6
, 400 MHz): δ ppm 8.24
5
.1.6.3. 1,3-Bis((1-((5,7-dimethyl-2-oxo-2H-chromen-4-yl)methyl)-1H-
,2,3-triazol-4-yl)methyl)-6-methylpyrimidine-2,4(1H,3H)-dione
(s, 2H, Tri-H’s), 7.36–6.96 (m, 10H, Cou and cyclic urea Ar-H), 5.89 (s,
4H, Cou-C -CH ’s), 5.81 (s, 2H, Cou-C -H’s), 5.12 (s, 4H, cyclic urea-N
& N -CH ); C NMR (DMSO‑d , 100 MHz): δ
1
4
2
3
1
−
1
13
(
7d). White; yield 82%; m.p: 266–268 °C; IR (KBr) cm
1659 and
3
2
’s), 3.74 (s, 6H, eOCH
3
6
1
1
703 (cyclic ureide C]O), 1728 (lactone C]O); H NMR (DMSO‑d
00 MHz): δ ppm 8.12 and 7.98 (2s, 2H, Tri-H’s), 7.02 and 7.01 (2s, 4H,
and C H’s), 6.08 and 6.05 (2s, 4H, Cou-C -CH ’s), 5.71 (s, 1H,
& N -CH ’s),
), 2.42 (s, 6H,
6
,
ppm 160.05, 156.10, 153.41, 150.21, 147.89, 143.55, 129.15, 125.21,
4
121.67, 120.19, 118.39, 118.01, 114.90, 108.94, 108.11, 56.28, 49.79,
Cou-C
6
8
4
2
36.37; MS (ESI+) m/z: Calcd. for C35
H
28
N
8
O -672.2081; Found:
7
cyclic ureide-H), 5.11 and 5.07 (2s, 4H, cyclic ureide-N
1
3
2
673.2830 [M+H+ ].
%
4
.97 and 4.90 (2s, 2H, Cou-C
3
-H’s), 2.63 (s, 6H, eCH
3
1
3
eCH
3
), 2.30 (s, 3H, eCH
3
); C NMR (DMSO‑d
6
, 100 MHz): δ ppm
5.1.7.3. 1,3-Bis((1-((7-methoxy-2-oxo-2H-chromen-4-yl)methyl)-1H-
1,2,3-triazol-4-yl)methyl)-1H-benzo[d]imidazol-2(3H)-one (10d). Light
pink; yield 83%; m.p: 278–280 °C; IR (KBr) cm−1 1692 (cyclic urea
1
1
61.46, 159.71, 154.96, 154.04, 153.77, 151.94, 143.01, 137.03,
30.37, 125.75, 125.25, 116.06, 114.95, 111.37, 101.37, 52.68,
10

N. Khanapurmath, et al.
Bioorganic & Medicinal Chemistry xxx (xxxx) xxxx
1
−1
C]O), 1708 (lactone C]O); H NMR (DMSO‑d
6
5
, 400 MHz): δ ppm 8.22
-H), 7.15–6.92 (m, 8H,
-CH ’s), 5.57 (s, 2H, Cou-
’s), 3.81 (s, 6H, eOCH );
79%; m.p: 286–288 °C; IR (KBr) cm
1708 (cyclic urea C]O), 1731
1
(
s, 2H, Tri-H’s), 7.67 (d, 2H, J = 9.2 Hz, Cou-C
(lactone C]O); H NMR (DMSO‑d
6
, 400 MHz): δ ppm 8.35 (d, 2H,
Cou and cyclic urea Ar-H), 5.84 (s, 4H, Cou-C
4
2
J = 8.8 Hz, Cou-C
7
-H), 8.240 (m, 4H, Tri-H’s and Cou-C -H), 8.05–8.03
8
C
3
-H’s), 5.11 (2s, 4H, cyclic urea-N
1
& N
3
-CH
2
3
(m, 2H, Ar-H), 7.58–7.52 (m, 6H, Ar-H), 7.12–6.99 (m, 4H, cyclic urea
Ar-H), 6.36 (s, 4H, Cou-C -CH ’s), 5.45 (s, 2H, Cou-C -H’s), 5.14 (2s,
, 100 MHz): δ ppm
1
3
C NMR (DMSO‑d
6
, 100 MHz): δ ppm 163.23, 160.32, 155.53, 153.42,
4
2
3
1
3
1
50.81, 143.49, 129.15, 126.35, 125.19, 121.67, 112.93, 110.96,
4H, cyclic urea-N
1
& N
3
-CH
2
’s); C NMR (DMSO‑d
6
1
10.80, 108.95, 101.59, 56.53, 49.71, 36.37; MS (ESI+) m/z: Calcd.
159.49, 154.77, 153.47, 153.13, 143.58, 135.04, 131.46, 130.19,
129.18, 129.11, 128.96, 126.30, 125.95, 125.39, 121.68, 117.94,
+
%
for C35
H
28
N
8
O -672.2081; Found: 673.2830 [M+H ].
7
1
13.43, 112.96, 108.94, 53.66, 36.44; MS (EI) m/z: Calcd. for
+%
5
.1.7.4. 1,3-Bis((1-((6-chloro-2-oxo-2H-chromen-4-yl)methyl)-1H-1,2,3-
C
41
H
28
N
8
O -712.2183; [M ]not found.
5
triazol-4-yl)methyl)-1H-benzo[d]imidazol-2(3H)-one (10e). Light brown;
−
1
yield 81%; m.p: 258–260 °C; IR (KBr) cm
1699 (cyclic urea C]O),
, 400 MHz): δ ppm 8.19 (s, 2H,
-H), 7.65 (dd, 2H, J = 8.8 and
-H), 7.42 (d, 2H, J = 8.8 Hz, Cou-C -H), 7.13 (dd, 2H,
J = 6 and 3.2 Hz, cyclic urea Ar-H), 6.97 (dd, 2H, J = 6 and 3.2 Hz,
5.1.7.9. 1,3-Bis((1-((2-oxo-2H-benzo[h]chromen-4-yl)methyl)-1H-1,2,3-
1
1
728 (lactone C]O); H NMR (DMSO‑d
6
triazol-4-yl)methyl)-1H-benzo[d]imidazol-2(3H)-one (10j). Pink; yield
−
1
Tri-H’s), 7.86 (d, 2H, J = 2.8, Cou-C
.8 Hz, Cou-C
5
82%; m.p: 290–292 °C; IR (KBr) cm
1713 (Cyclic urea C]O), 1736
1
2
7
8
(lactone C]O); H NMR (DMSO‑d
6
, 400 MHz): δ ppm 8.29–8.24 (m,
4H, Tri-H’s and Ar-H), 8.02–7.96 (m, 6H, Ar-H), 7.45 (d, 2H,
J = 8.8 Hz, Cou-C -H), 7.29 (d, 2H, J = 8.8 Hz, Cou-C -H), 7.14–6.96
(m, 4H, cyclic urea Ar-H), 5.94 (s, 4H, Cou-C -CH ’s), 5.56 (s, 2H, Cou-
-H’s), 5.15 (2s, 4H, cyclic urea-N & N -CH ’s); MS (ESI+) m/z:
Calcd. for C41 -712.2183; Found: 713.3038 [M+H ].
cyclic urea Ar-H), 5.88 (s, 6H, Cou-C
4
-CH
2
’s and Cou-C
3
-H’s), 5.12 (2s,
6
5
1
3
4
1
1
H, cyclic urea-N
1
& N
3
-CH
2
’s); C NMR (DMSO‑d
6
, 100 MHz): δ ppm
4
2
59.34, 156.06, 152.34, 149.49, 143.58, 142.01, 139.08, 132.94,
29.29, 129.15, 124.83, 119.24, 119.10, 115.70, 49.81, 41.18, 35.34;
C
3
1
3
2
+
%
H
28
N
O
8 5
MS (ESI+) m/z: Calcd. for C33
H
22Cl
N
2 8
O -680.1090; Found: 681.1902
5
+
%
[
M+H ].
5.1.7.10. 4-((4-((2-Oxo-3-((1-((2-oxo-1,2-dihydroquinolin-4-yl)methyl)-
H-1,2,3-triazol-4-yl)methyl)-2,3-dihydrobenzo[d]imidazol-1-yl)methyl)-
1
5
.1.7.5. 1,3-Bis((1-((6-isopropyl-2-oxo-2H-chromen-4-yl)methyl)-1H-
1H-1,2,3-triazol-1-yl)methyl)quinolin-2(1H)-one (10k). White; yield
−1
1
,2,3-triazol-4-yl)methyl)-1H-benzo[d]imidazol-2(3H)-one
(10f). Off
1703 (cyclic urea
, 400 MHz): δ ppm 8.24
-H), 7.49 (dd, 2H, J = 8.4
-H), 7.31 (d, 2H, J = 8.4 Hz, Cou-C -H), 7.14 (dd, 2H,
J = 6 and 3.2 Hz, cyclic urea Ar-H), 6.96 (dd, 2H, J = 6 and 3.2 Hz,
cyclic urea Ar-H), 5.91 (s, 4H, Cou-C -CH ’s), 5.81 (s, 2H, Cou-C -H’s),
.11 (2s, 4H, cyclic urea-N & N -CH ’s), 2.87 (sept, 2H, J = 7 Hz,
eCH), 1.12 (d, 12H, J = 7 Hz, eCH
85%; m.p: 274–276 °C; IR (KBr) cm
1670 (lactam C]O), 1695
, 400 MHz): δ
−
1
1
white; yield 89%; m.p: 252–254 °C; IR (KBr) cm
(cyclic urea C]O), 3411 (eNeH); H NMR (DMSO‑d
6
1
C]O), 1726 (lactone C]O); H NMR (DMSO‑d
6
ppm 11.76 (s, 2H, eNH), 8.19 (s, 2H, Tri-H’s), 7.74–6.96 (m, 12H, Ar-
(
s, 2H, Tri-H’s), 7.56 (d, 2H, J = 2 Hz, Cou-C
5
H), 5.84 (s, 4H, 1Aza cou-C
4
-CH
2
’s), 5.92 (s, 2H, 1-Aza cou-C -H’s),
3
1
3
and 2 Hz, Cou-C
7
8
5.10 (2s, 4H, cyclic urea-N
1
& N
3
-CH
2
’s);
C NMR (DMSO‑d ,
6
100 MHz): δ ppm 161.69, 153.44, 145.83, 143.36, 139.45, 131.33,
4
2
3
129.21, 124.96, 124.53, 122.45, 121.66, 120.94, 117.59, 116.27,
5
1
3
3
2
108.94, 50.19, 36.43; MS (ESI−) m/z: Calcd. for C33
H
26
N
10 3
O -
1
3
+%
); C NMR (DMSO‑d
6
, 100 MHz): δ
610.2189; Found: 609.1113 [M−1 ].
ppm 160.07, 153.39, 151.90, 150.52, 145.28, 143.49, 131.40, 129.15,
1
3
6
25.20, 122.51, 121.65, 117.31, 117.15, 114.45, 108.91, 66.87, 49.77,
3.50, 24.23; MS (ESI+) m/z: Calcd. for C39 -696.2809; Found:
97.3626 [M+H ].
5.1.7.11. 8-Methyl-4-((4-((3-((1-((8-methyl-2-oxo-1,2-dihydroquinolin-
4-yl)methyl)-1H-1,2,3-triazol-4-yl)methyl)-2-oxo-2,3-dihydrobenzo[d]
imidazol-1-yl)methyl)-1H-1,2,3-triazol-1-yl)methyl)quinolin-2(1H)-one
H
36
N
O
8 5
+
%
−1
(
10l). White; yield 82%; m.p: 268–270 °C; IR (KBr) cm 1668 (lactam
1
5
.1.7.6. 1,3-Bis((1-((5,7-dimethyl-2-oxo-2H-chromen-4-yl)methyl)-1H-
C]O), 1706 (cyclic urea C]O), 3428 (eNeH); H NMR (DMSO‑d
6
,
1
,2,3-triazol-4-yl)methyl)-1H-benzo[d]imidazol-2(3H)-one
(10g). Off
400 MHz): δ ppm 11.45 (s, 2H, eNH), 8.21 (s, 2H, Tri-H’s), 7.24–6.83
−
1
white; yield 84%; m.p: 270–272 °C; IR (KBr) cm
1692 (cyclic urea
(m, 10H, Ar-H), 5.87 (s, 4H, 1Aza cou-C
-H’s), 5.14 (2s, 4H, cyclic urea-N
Calcd. for C35
4
-CH
2
3
’s), 5.95 (s, 2H, 1-Aza cou-
1
C]O), 1716 (lactone C]O); H NMR (DMSO‑d
6
, 400 MHz): δ ppm 8.10
C
3
1
& N
-CH ’s); MS (ESI−) m/z:
2
+
%
(
s, 2H, Tri-H’s), 6.99 (s, 2H, Cou-C
dd, 2H, J = 6 and 3.2 Hz, cyclic urea Ar-H), 7.05 (m, 2H, cyclic urea
-CH ’s), 5.09 (s, 2H, Cou-C -H’s), 5.16 (2s,
-CH ’s), 2.61 (s, 6H, eCH ), 2.31 (s, 6H, eCH );
6
-H), 6.94 (s, 2H, Cou-C
8
-H), 7.16
H
30
N
10
O
3
-638.2502; Found: 639.3233 [M+H ].
(
Ar-H), 6.04 (s, 4H, Cou-C
4
2
3
5.1.7.12. 6-Chloro-4-((4-((3-((1-((6-chloro-2-oxo-1,2-dihydroquinolin-4-
yl)methyl)-1H-1,2,3-triazol-4-yl)methyl)-2-oxo-2,3-dihydrobenzo[d]
imidazol-1-yl)methyl)-1H-1,2,3-triazol-1-yl)methyl)quinolin-2(1H)-one
4
H, cyclic urea-N
1
& N
3
2
3
3
1
3
C NMR (DMSO‑d , 100 MHz): δ ppm 159.57, 155.10, 153.38, 147.40,
6
−
1
1
1
45.54, 143.65, 142.96, 136.97, 130.40.26, 130.22, 129.29, 125.13,
(10m). White; yield 78%; m.p: 286–288 °C; IR (KBr) cm
1670
1
16.12, 115.03, 108.85, 52.66, 39.66, 23.79, 21.25; MS (ESI−) m/z:
(lactam C]O), 1701 (cyclic urea C]O), 3431 (eNeH); H NMR
+
%
Calcd. for C37
H
32
N
8
O
5
-668.2496; Found: 667.0262 [M−1 ].
(DMSO‑d
H’s), 7.81 (s, 2H, Cou-C
(d, 2H, J = 9.2 Hz, Cou-C
5.83 (s, 4H, 1Aza cou-C -CH
6
, 400 MHz): δ ppm 11.81 (s, 2H, eNH), 8.16 (s, 2H, Tri-
-H), 7.51 (d, 2H, J = 8.8 Hz, Cou-C -H), 7.30
-H), 7.14–6.96 (m, 4H, cyclic urea Ar-H),
’s), 6.02 (s, 2H, Cou-C -H’s), 5.11 (2s, 4H,
5
7
5
.1.7.7. 1,3-Bis((1-((7,8-dimethyl-2-oxo-2H-chromen-4-yl)methyl)-1H-
8
1
,2,3-triazol-4-yl)methyl)-1H-benzo[d]imidazol-2(3H)-one
(10h). Off
4
2
3
−
1
13
white; yield 83%; m.p: 282–284 °C; IR (KBr) cm
1698 (cyclic urea
cyclic urea-N
1
& N
3
-CH
2
’s), 2.30 (s, 6H, eCH
3
); C NMR (DMSO‑d ,
6
1
C]O), 1731 (lactone C]O); H NMR (DMSO‑d
6
, 400 MHz): δ ppm 8.20
100 MHz): δ ppm 161.41, 153.52, 145.01, 142.39, 141.50, 138.28,
(
s, 2H, Tri-H’s), 7.48 (d, 2H, J = 8.8, Cou-C
5
-H), 6.97 (d, 2H,
134.33, 131.18, 129.28, 126.59, 124.03, 123.34, 122.27, 121.10,
J = 9.2 Hz, Cou-C
6
-H), 7.15–6.98 (m, 4H, cyclic urea Ar-H), 5.84 (s,
118.84, 49.99, 38.91; MS (EI) m/z: Calcd. for
C
33
H
24Cl
2
N
10
3
O -
+
%
4
H, Cou-C
4
-CH
2
’s), 5.70 (s, 2H, Cou-C
3
-H’s), 5.11 (2s, 4H, cyclic urea-
678.1410; [M+H ] not found.
1
3
N
1
& N
3
-CH
2
’s), 2.31 (s, 6H, eCH
3
), 2.21 (s, 6H, eCH ); C NMR
3
(
DMSO‑d
6
, 100 MHz): δ ppm 160.11, 153.46, 151.69, 150.83, 143.49,
5.1.7.13. 7-Chloro-4-((4-((3-((1-((7-chloro-2-oxo-1,2-dihydroquinolin-4-
yl)methyl)-1H-1,2,3-triazol-4-yl)methyl)-2-oxo-2,3-dihydrobenzo[d]
1
42.52, 129.20, 126.24, 125.14, 124.51, 121.91, 121.66, 115.28,
1
12.92, 108.94, 49.71, 36.43, 20.39, 11.72; MS (ESI−) m/z: Calcd.
imidazol-1-yl)methyl)-1H-1,2,3-triazol-1-yl)methyl)quinolin-2(1H)-one
+
%
−1
1
for C37
H
32
8
N O
5
-668.2496; Found: 667.0375 [M−1 ].
(10n). White; yield 75%; m.p: 294–296 °C; IR (KBr) cm
1667
(
lactam C]O), 1698 (cyclic urea C]O), 3443 (eNeH); H NMR
5
.1.7.8. 1,3-Bis((1-((3-oxo-3H-benzo[f]chromen-1-yl)methyl)-1H-1,2,3-
(DMSO‑d
6
, 400 MHz): δ ppm 11.75 (s, 2H, eNH), 8.15 (s, 2H, Tri-
triazol-4-yl)methyl)-1H-benzo[d]imidazol-2(3H)-one (10i). Green; yield
H’s), 7.73 (d, 2H, J = 8.4 Hz, Cou-C
5
-H), 7.31 (s, 2H, Cou-C -H), 7.17
8
11

N. Khanapurmath, et al.
Bioorganic & Medicinal Chemistry xxx (xxxx) xxxx
(
d, 2H, J = 8.4 Hz, Cou-C
6
-H), 7.13–6.95 (m, 4H, cyclic urea Ar-H),
Appendix A. Supplementary data
5
.81 (s, 4H, Cou-C -CH ’s), 5.96 (s, 2H, Cou-C -H’s), 5.10 (2s, 4H, cyclic
4
2
3
urea-N
1
& N
3
-CH
2
’s); MS (ESI−) m/z: Calcd. for C33
H
24Cl
2
N
10
O
3
-
Supplementary data (various spectra of synthesized compounds,
single crystal X-ray data of compounds 6 and 4c and in silico studies) to
this article can be found online at https://doi.org/10.1016/j.bmc.2019.
+
%
6
78.1410; Found: 677.1089 [M−1 ].
1
15054.
5
.2. In vitro antitubercular activity
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