Synthesis of benzotriazoles derivatives and their dual potential as α-amylase and α-glucosidase inhibitors in vitro: Structure-activity relationship, molecular docking, and kinetic studies

Article abstract of DOI:10.1016/j.ejmech.2019.111677

Benzotriazoles (4–6) were synthesized which were further reacted with different substituted benzoic acids and phenacyl bromides to synthesize benzotriazole derivatives (7–40). The synthetic compounds (7–40) were characterized via different spectroscopic techniques including EI-MS, HREI-MS, ¹H-, and ¹³C NMR. These molecules were examined for their anti-hyperglycemic potential hence were evaluated for α-glucosidase and α-amylase inhibitory activities. All benzotriazoles displayed moderate to good inhibitory activity in the range of IC₅₀ values of 2.00–5.6 and 2.04–5.72 μM against α-glucosidase and α-amylase enzymes, respectively. The synthetic compounds were divided into two categories “A” and “B”, in order to understand the structure-activity relationship. Compounds 25 (IC₅₀ = 2.41 ± 1.31 μM), (IC₅₀ = 2.5 ± 1.21 μM), 36 (IC₅₀ = 2.12 ± 1.35 μM), (IC₅₀ = 2.21 ± 1.08 μM), and 37 (IC₅₀ = 2.00 ± 1.22 μM), (IC₅₀ = 2.04 ± 1.4 μM) with chloro substitution/s at aryl ring were found to be most active against α-glucosidase and α-amylase enzymes. Molecular docking studies on all compounds were performed which revealed that chloro substitutions are playing a pivotal role in the binding interactions. The enzyme inhibition mode was also studied and the kinetic studies revealed that the synthetic molecules have shown competitive mode of inhibition against α-amylase and non-competitive mode of inhibition against α-glucosidase enzyme.

Full text of DOI:10.1016/j.ejmech.2019.111677

European Journal of Medicinal Chemistry 183 (2019) 111677
Contents lists available at ScienceDirect
European Journal of Medicinal Chemistry
journal homepage: http://www.elsevier.com/locate/ejmech
Research paper
Synthesis of benzotriazoles derivatives and their dual potential as
-amylase and -glucosidase inhibitors in vitro: Structure-activity
a
a
relationship, molecular docking, and kinetic studies
Shehryar Hameed a, Kanwal a, Faiza Seraj a, Rafaila Rafique a, Sridevi Chigurupati b,
Abdul Wadood c, Ashfaq Ur Rehman c, Vijayan Venugopal d, Uzma Salar e,
, f, *
Muhammad Taha f, Khalid Mohammed Khan a
a H. E. J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, 75270, Pakistan
b Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, Qassim University, Buraidah, 52571, Saudi Arabia
c Department of Biochemistry, Computational Medicinal Chemistry Laboratory, UCSS, Abdul Wali Khan University, Mardan, Pakistan
d Faculty of Pharmacy, AIMST University, Kedah, 08100, Malaysia
e Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi,
75270, Pakistan
f Department of Clinical Pharmacy, Institute for Research and Medical Consultations (IRMC), Imam Abdulrahman Bin Faisal University, P.O. Box 1982,
Dammam, 31441, Saudi Arabia
a r t i c l e i n f o
a b s t r a c t
Article history:
Benzotriazoles (4e6) were synthesized which were further reacted with different substituted benzoic
acids and phenacyl bromides to synthesize benzotriazole derivatives (7e40). The synthetic compounds
Received 14 June 2019
Received in revised form
9 August 2019
Accepted 2 September 2019
Available online 5 September 2019
(7e40) were characterized via different spectroscopic techniques including EI-MS, HREI-MS, 1H-, and 13
C
NMR. These molecules were examined for their anti-hyperglycemic potential hence were evaluated for
-glucosidase and -amylase inhibitory activities. All benzotriazoles displayed moderate to good
inhibitory activity in the range of IC50 values of 2.00e5.6 and 2.04e5.72 M against -glucosidase and
amylase enzymes, respectively. The synthetic compounds were divided into two categories “A” and “B”,
a
a
m
a
a-
Keywords:
Benzotriazoles
in order to understand the structure-activity relationship. Compounds 25 (IC50 ¼ 2.41 1.31
m
M),
M),
a-
(IC50 ¼ 2.5 1.21
(IC50 ¼ 2.04 1.4
glucosidase and
m
M), 36 (IC50 ¼ 2.12 1.35
m
M), (IC50 ¼ 2.21 1.08 M), and 37 (IC50 ¼ 2.00 1.22
m
m
a-Amylase inhibition
m
M) with chloro substitution/s at aryl ring were found to be most active against
a-glucosidase inhibition
a
-amylase enzymes. Molecular docking studies on all compounds were performed
Diabetes
In silico studies
Kinetic studies
which revealed that chloro substitutions are playing a pivotal role in the binding interactions. The
enzyme inhibition mode was also studied and the kinetic studies revealed that the synthetic molecules
have shown competitive mode of inhibition against
against -glucosidase enzyme.
a
-amylase and non-competitive mode of inhibition
a
© 2019 Elsevier Masson SAS. All rights reserved.
1. Introduction
langerhans) which are responsible to produce insulin in the human
body, the diabetic patients either do not produce or are unable to
utilize it properly. This dysfunction leads to high blood glucose
(sugar) levels in the body leading to hyperglycemia. Diabetes may
be of two types, insulin dependent which is due to lack of insulin
production in the human body is called as type 1, however, in the
type 2 diabetes the body system is either unable to produce or not
utilizing the insulin properly. It is among the most common chronic
diseases after cancer and cardiovascular diseases which leads to
mortality [1,2].
Diabetes mellitus (DM), is a most common and epidemic dis-
order of the century which effects the metabolic functions of the
endocrine system. It is widely spread in all parts of the world and is
increasing rapidly. Due to the damage of specialized cells (islets of
* Corresponding author. H. E. J. Research Institute of Chemistry, International
Center for Chemical and Biological Sciences, University of Karachi, Karachi, 75270,
Pakistan.
Due high prevalence of diabetic, various approaches have been
E-mail addresses: khalid.khan@iccs.edu, drkhalidhej@gmail.com (K.M. Khan).
https://doi.org/10.1016/j.ejmech.2019.111677
0223-5234/© 2019 Elsevier Masson SAS. All rights reserved.

2
S. Hameed et al. / European Journal of Medicinal Chemistry 183 (2019) 111677
made to control and manage the disorders caused by it. However,
inhibition of carbolytic enzymes such as -glucosidase and a-
amylase is one of the common approach to manage or minimize
these metabolic disorders [3]. Amylase, protease, and lipase are
most commonly used enzymes in industry, and food biotechnology
of heterocyclic organic molecules of different category and classes
in search of their potential uses in medicinal chemistry [17e24]. In
the recent past, we had identified and reported benzimidazoles,
a
pyrazolones, and imidazoles as potential
a-glucosidase and
a-
amylase inhibitors (Fig. 3) [18]. Keeping in mind the
a-glucosidase
[4,5].
a
-Amylase (EC 3.2.1.1) an enzyme which catalyzes hydrolysis
potential of benzimidazoles and related compounds, we deliber-
ately designed, synthesized, and evaluated 1,2,3-triazoles (benzo-
of polysaccharides, commonly starch to glucose and maltose [6]. It
belongs to the family of metalloenzyme having calcium atom as a
metal co-factor [5]. Starch is absorbed into our body by the hy-
drolytic action of
glucosidase enzyme [4]. Inhibitors of
modulating the blood glucose level after a meal. Thus potential
inhibitors of -amylase enzyme can be used clinically as chemo-
triazole) for
a-amylase and a-glucosidase inhibition in order to
identify lead molecules which may act as dual inhibitors. The
treatment of diabetic patients often need (medicine) a combination
therapy due to the slow healing process. Therefore, it is still need to
explore more compounds for this disease in order to develop lead
candidates to carry out some advance research in future. Thus, we
decided to screen a library of substituted 1,2,3-benzotriazoles
a-amylase followed by the action of intestinal
a-
a-amylase function by
a
therapeutic agents for the treatment of diabetes as well as obesity
[6,7].
(7e40) and found that many compounds are dual inhibitors of
glucosidase and -amylase enzymes.
a-
Besides the use of multiple approaches,
a-glucosidase (EC
a
3.2.1.20) enzyme inhibitors are amongst the alternative therapeutic
method [8] used clinically for the treatment of diabetes. The in-
hibitors of this enzyme slow down the digestion process thus
resulting in the slow absorption of glucose. Acarbose and miglitol
2. Results and discussion
2.1. Chemistry
are among the most common a-glucosidase inhibitors used clini-
cally to reduce postprandial blood glucose level (Fig. 1). These
clinical drugs inhibit formation of glucose in the small intestine by
Benzotriazoles 7e40 were synthesized by treating benzene-1,2-
diamines (1e3) with CH3COOH and NaNO2 to give different
substituted benzotriazoles (4e6). Benzotriazoles were then reacted
with different substituted phenacyl bromides in ethanol and trie-
thylamine at 60e70 ꢀC to give N-substituted benzotriazoles de-
rivatives (25e40). Benzotriazoles (4e6) were also treated with
different substituted benzoic acid in the presence of CDI (1,1ʹ-car-
bonyldiimidazole) as coupling agent in acetonitrile at 70e80 ꢀC.
The carboxylic group of acid was converted into good leaving group
by treating it with coupling reagent CDI. In this reaction, acid
imidazole reactive intermediate was formed, and carbon dioxide
(CO2) is liberated afterward the elimination of imidazole ring takes
place. The acid imidazole being unstable reacts immediately with
1,2,3-triazoles to afford N-substitued benzotriazoles (7e24)
(Scheme 1). All synthetic benzotriazoles (7e40) were fully charac-
terized by different spectroscopic techniques including 1H, 13C
NMR, EI-MS, HREI-MS, and IR.
inhibiting
a-glucosidase enzyme. Acarbose, an anti-diabetic drug
and tetrasaccharide mimic, with potent
a
-amylase and -glucosi-
a
dase inhibitory activity is used currently in the treatment of T2DM
[9]. However, various side effects including flatulence and
abdominal pain are related with acarbose. These side effects often
limit the use of drug alone, thus used in combination with other
anti-diabetic medicines to improve the efficacy. Thus, there is a dire
need to design and develop a more potential molecules having less
side effects to cure diabetes mellitus [10].
The heterocyclic scaffold as being the center for pharmacolog-
ical activity have attracted a considerable attention of medicinal
chemist. Triazoles are heterocyclic compounds composed of a five-
membered unsaturated ring with three nitrogen and two carbon
atoms at non-adjacent positions. Triazoles exist in different
isomeric forms based on the position of nitrogen (N) atoms in the
ring [11,12]. Since decades, triazoles and its related compounds
have attracted great attention of chemists as well as biologists due
to their chemotherapeutical importance [13,14]. The literature
search reveals that 1H-1,2,3-triazoles nucleus is a core structural
component in number of drugs having different pharmacological
properties such as antiinflammatory, antimicrobial, antiviral, and
antiparasitic. These molecules also found to have analgesic effects
along with antineoplastic, anaesthetic, antiepileptic, antidepres-
sant, antioxidant, anti-Parkinson0s, anti-diabetic, and anti-obesity
properties (Fig. 2) [15e17].
2.2. EI-MS spectrometry of characteristic compound
EI-MS spectra of compounds 8 and 28 of category A and B,
respectively, were discussed below. EI-MS spectra of compound 8
showed the molecular ion peak at m/z 325 for molecular formula
C
13H6Cl3N3O. The two isotopic peaks [Mþþ2] and [Mþþ4] due to
the presence of chlorine atoms were appeared at m/z 327 and 329,
respectively. The significant fragment appeared at m/z 289 by the
loss of chlorine. Another fragment appeared at m/z 185 confirms
the formation of 3,4-dichloro-1H-benzo[d] [1e3] triazole, while,
the formation of 1-(3-chlorophenyl) ethan-1-one was confirmed by
the significant fragment at m/z 139 (Fig. 4).
Heterocyclic compounds are of special interest to medicinal
chemists due to their exceptional chemical and versatile biological
profiles. Therefore, our research group had explored large number
Fig. 1. Clinical medicine for the therapeutic of type II diabetes mellitus.

S. Hameed et al. / European Journal of Medicinal Chemistry 183 (2019) 111677
3
Fig. 2. 1,2,3-triazole containing commercial drugs and bioactive molecules.
Fig. 3. Rationale of the current Study.
EI-MS spectra of compound 28 from “Category B00, showed the
molecular ion peak at m/z 315 for molecular formula C14H10BrN3O.
The [Mþþ2] isotopic peak of bromine was appeared at m/z 317. The
significant fragment appears at m/z 236 by the loss of bromine
atom. The fragment appeared at m/z 133 confirms the formation of
1-methyl-1H-benzo[d] [1e3] triazole, while the formation of 3-
bromobenzaldehyde was confirmed by the significant fragment at
m/z 183. The key fragments are presented in (Fig. 4).
(DMSO‑d6) on a Bruker AM 300 MHz instrument (Fig. 5). The most
downfield singlets of two CH protons of benzotriazole ring reso-
nated at dH 8.79 and 8.51, respectively. The molecule comprises of
an aryl ring having 4 protons, among them, signal of proton H-60
0
0
0
0
0
appeared at dH 8.12 as triplet (J 6 ,2 /6 ,4 ¼1.8 Hz, 1H, H-6 ), showing
meta, coupling with H-20 & H-40. While, C-20 and C-40 protons were
40,30
40,60
resonated at dH 7.87 (J
¼ 7.2 Hz, J
¼ 1.2 Hz) and 8.06 (J
20,30
¼ 7.8 Hz) as double doublet and doublet, respectively. However,
H-30 appeared at
d
7.71 as triplet showing coupling with H-20 and
H-40 having coupling constant J3 ,2 /3 ,4 ¼ 8.1 Hz (Fig. 5).
0
0
0
0
2.3. 1H NMR
1H NMR spectrum of compound 28 was recorded in DMSO‑d6 on
a Bruker AM 300 MHz instrument (Fig. 6). The compound com-
prises of the total ten protons, the most downfield proton H-20
2.3.1. “Category A00
The 1H NMR spectrum of compound 8 was recorded in

4
S. Hameed et al. / European Journal of Medicinal Chemistry 183 (2019) 111677
Scheme 1. Synthesis of novel benzo-1,2,3-triazoles derivatives (7e40).
Fig. 5. 1H NMR chemical shifts of representative compound 8.
Fig. 6. 1H NMR chemical shifts of representative compound 28.
constant value of 7.8 Hz showing coupling with H-1 and H-3,
respectively, however, H-3 resonated at dH 7.55 (J2(1,3) ¼ 7.8 Hz).
However, H-50 of acetophenone moiety appeared at
d 7.44 as triplet
showing coupling with H-40 and H-60 with coupling constant value
of 7.8 Hz. The CH2 protons were resonated as a singlet at dH 6.59
(Fig. 6).
Fig. 4. Key fragmentation of representative compounds 8 and 28.
showing a singlet and appeared at
d
8.29. The other two aromatic
2.4. In vitro a-amylase and a-glucosidase inhibitory activities
proton H-40 and H-60 of acteophenone ring also resonated at dH 8.11
0
0
0
0
0
(J 6 ,5 /4 ,5 ¼ 7.5 Hz) as a doublet showing ortho, coupling with H-5 ,
respectively. H-1 and H-4 protons of benzotriazole ring were the
most downfield due to presence of three nitrogen atoms in the
triazole ring and resonated as dH 7.97 and dH 7.81 as doublet,
respectively. The H-2 resonated at dH 7.62 as triplet with coupling
All synthetic benzotriazoles derivatives (7e40) were screened
for in vitro -amylase and -glucosidase inhibitory activities. It is
a
a
noteworthy that all benzotriazole compounds displayed moderate
to good inhibitory activity against both enzymes as compared to
standard acarbose (Table-1). The synthetic derivatives have been

S. Hameed et al. / European Journal of Medicinal Chemistry 183 (2019) 111677
5
divided into two categories in order to understand the better
structure-activity relationship (SAR). “Category A00 comprises of
eighteen derivatives (7e24) that are derived from reaction of
benzotriazole with different substituted benzoic acids having an
amide bond, while “Category B00 is composed of sixteen molecules
(25e40) synthesized via reaction of benzotriazole with phenacyl
bromides possessing active methylene and acetophenone part
(Fig. 7). The limited structure-activity relationship (SAR) suggested
that all structural features such as benzotriazole ring, amide group,
acetophenone, and aryl part are actively participating in the activity
and any variation in the activity is attributed to the different sub-
stitution groups on aryl ring (R3) and benzotriazole part (R1 and R2).
decreased activity. Compound 14 (IC50 ¼ 3.13 1.18
m
M) with
bromo group at para position was slightly less active as compared
to fluoro substituted compound 11.
Compounds 15 and 16 having methoxy substitutions showed
variable degree of inhibition. Amongst them compound 15
(IC50 ¼ 2.98 1.09
mM) bearing methoxy group at para position was
the second most active compound of this category which indicates
that para methoxy moiety may interacted more proficiently with
the enzyme. The change in position of methoxy from para to ortho
in compound 16 (IC50 ¼ 4.77 1.30
mM), however, displayed
decreased activity. Replacement of methoxy with methyl group at
different position of aryl part also resulted in decreased activity.
Compounds 17 (IC50 ¼ 4.3 1.15
mM) with meta-methyl group dis-
played less activity as compared to the standard acarbose. The
2.5. Structure-activity relationship (SAR) for
activity
a
-amylase inhibitory
addition of another methyl group at para position as in compound
18 (IC50 ¼ 4.73 1.22
m
M) resulted in further decrease in activity.
For each category, limited structure-activity relationship was
discussed based on variable substituted “R” groups. Since, the re-
sults revealed that the main and persistent structural features in
both categories such as (benzotriazole ring, amide, and acetophe-
Interestingly, compound 19 (IC50 ¼ 4.12 1.23
mM) with three
methyl groups adjacent to each other was slightly more active as
compared to compound 17 (Fig. 10).
Compound 20 (IC50 ¼ 2.92 1.81
tion demonstrated better -amylase inhibitory activity as
M) having an
mM) with para nitro substitu-
none moiety) are taking important role in the (SAR) for
a-amylase
a
inhibitory activity, nonetheless, the variation in the activities is the
result of variable features at benzotriazole (R1, R2) and aryl rings
(R3).
compared to compound 21 (IC50 ¼ 4.08 1.09
m
additional methyl group showed less activity which confirmed that
methyl group are not contributing in the activity. Incorporation of
amino
and
chloro
groups
as
in
compound
22
2.5.1. “Category A00
Compounds 8, 9, and 10 having chloro substituted benzotriazole
ring exhibited potential inhibitory activity. Among them, com-
pound 8 (IC50 ¼ 2.99 1.43
position of aryl part was found to be most active. However, com-
pounds 9 (IC50 ¼ 3.66 1.18 M) and 10 (IC50 ¼ 3.66 1.04 M)
(IC50 ¼ 4.28 1.45
m
M) also lead to slight decreased
a-amylase
inhibitory potential. However, compounds 23 (IC50 ¼ 5.4 1.40
mM)
and 24 (IC50 ¼ 5.38 1.4
mM) with butoxy, and unsubstituted
m
M) with chloro substitution at meta
phenyl ring also found to be less active (Fig. 11).
m
m
2.5.2. “Category B00
bearing unsubstituted and dimethyl substituted phenyl ring
showed comparable activity with respect to each other but
decreased activity as compared to compound 8. The enhanced ac-
tivity of compound 8 might be due to three chloro groups which
help in better interaction of molecule within the enzyme's pocket,
removal of chloro group or replacing chloro group with methyl
resulted in decreased activity as in compounds 9 and 10.
Compounds 25e40 belong to “Category B". In this category,
M), with mono chloro sub-
compound 25 (IC50 ¼ 2.41 1.31
m
stitutions at aryl part and unsubstituted benzotriazole ring,
respectively, showed good inhibitory potential. However, addition
of another chloro group to the adjacent position as in compound 26
(IC50 ¼ 3.89 1.09
position of chloro group from para to ortho as in compound 27
(IC50 ¼ 3.51 1.12 M) leads to slight better activity (Fig. 12).
Compound 28 (IC50 ¼ 2.76 1.04 M) bearing bromo group at para
position displayed almost comparable activity with compound 25.
M) with
mM) resulted in a decreased activity. Shifting the
Compound
7
(IC50 ¼ 3.32 1.32
mM) having dimethyl
m
substituted benzotriazole ring and unsubstituted aromatic ring
displayed comparable activity with the standard acarbose
m
(IC50 ¼ 2.00 1.35
m
M). However, it was less active as compared to
Its structurally similar analogue 29 (IC50 ¼ 4.35 1.09
m
compound 9, might be the replacement of chloro groups with
methyl at benzotriazole ring were responsible for the slight
decreased activity (Fig. 8).
meta bromo group at aryl ring showed almost two folds less activity
which shows that substitution at para position might be helpful in
better interaction with the active site of enzyme.
Compounds 11, 12, 13, and 14 with unsubstituted benzotriazole
ring and different halogen substituents at different position of aryl
ring were found to have varying degree of inhibitory potential.
Amongst them, para fluoro substituted compound 11
Compound 34 (IC50 ¼ 4.89 1.41
part was found to exhibit good inhibitory activity. Compound 35
(IC50 ¼ 4.92 1.45 M) with para phenyl substituted ring displayed
almost similar activity to compound 34. Compounds 30
M) with ortho hy-
droxy and meta nitro groups showed slightly variable activities.
Among them compound 31 having nitro group was most active
might be the electron withdrawing effect or the particular position
of nitro group is contributing in the activity. However, in the
mM) having unsubstituted aryl
m
(IC50 ¼ 2.8 1.19
m
M) showed potential inhibition as compared to
(IC50 ¼ 4.9 1.5
m
M) and 31 (IC50 ¼ 4.42 1.08
m
the standard acarbose (IC50 ¼ 2.00 1.35
mM). Compound 11 was
also found to be most active compound of the “Category A00, might
be unsubstituted benzotriazole part and substitution of fluoro
group have attained a favorable confirmation susceptible for mak-
ing
p
-
p
and other interactions with enzyme's active site (Fig. 9).
M)
methoxy
(IC50 ¼ 4.42 1.12
and
methyl
substituted
compounds
32
However, difluoro substituted compound 13 (IC50 ¼ 5.00 1.18
m
m
M) and 33 (IC50 ¼ 4.56 1.51
m
M) with substi-
bearing both fluoro groups at ortho positions of aryl ring showed
almost two folds less activity as compared to compound 11. The
decreased activity might be due to change in position of fluoro
group and addition of another group resulted in increased steric
factor resulting it less suitable to interact with active site of enzyme.
tution at para position compound 32 also exhibited good inhibitory
activity as compared to compound 33 (Fig. 13).
Amongst methyl substituted benzotriazole derivatives, com-
pounds 36 (IC50 ¼ 2.12 1.35
mM) with mono chloro substitutions
was found to be most active derivative of “Category B". Compari-
son of inhibitory activity of compound 36 with 25
Compound 12 (IC50 ¼ 5.72 1.12
mM) with additional chloro and
fluoro at ortho and meta positions, respectively, displayed further
declined activity as compared to compound 11 and 13 which again
showed that increasing the number of substituents leads to
(IC50 ¼ 2.41 1.31
mM) revealed that methyl groups at benzo-
triazole moiety in 36 played some important role in the inhibitory
potential. These methyl groups might involve in some non-polar or

6
S. Hameed et al. / European Journal of Medicinal Chemistry 183 (2019) 111677
Table 1
In vitro a-amylase and a-glucosidase inhibitory activities of benzotriazoles (7e40).
Compounds
R1
R2
R3
a-Amylase Inhibition
a-Glucosidase Inhibition
IC50 SEMa
(m
M)
IC50 SEMa
(mM)
“Category A”
7
8
CH3
Cl
CH3
Cl
3.32 1.32
2.99 1.43
3.4 1.09
3.00 1.21
9
Cl
Cl
3.66 1.18
3.82 1.42
10
11
12
Cl
H
H
Cl
H
H
3.66 1.04
2.8 1.19
5.72 1.12
3.7 1.3
2.82 1.02
5.63 1.24
13
H
H
5.0 1.18
5.23 1.54
14
15
H
H
H
H
3.13 1.01
2.98 1.09
3.2 1.12
2.99 1.08
16
H
H
4.77 1.3
4.79 1.12
17
18
19
H
H
H
H
H
H
4.3 1.15
4.73 1.22
4.12 1.23
4.42 1.09
4.8 1.12
4.23 1.07
20
21
H
H
H
H
2.92 1.81
4.08 1.09
2.97 1.7
4.1 1.23
22
H
H
4.28 1.45
4.32 1.23

S. Hameed et al. / European Journal of Medicinal Chemistry 183 (2019) 111677
7
Table 1 (continued )
Compounds
R1
R2
R3
a
-Amylase Inhibition
a-Glucosidase Inhibition
IC50 SEMa
5.4 1.40
(
mM)
IC50 SEMa
(mM)
23
H
H
5.6 1.11
24
H
H
5.38 1.4
5.29 1.3
“Category B"
25
26
H
H
H
H
2.41 1.31
3.89 1.09
2.5 1.21
3.9 1.08
27
28
H
H
H
H
3.51 1.12
4.35 1.09
3.47 1.31
4.41 1.14
29
30
H
H
H
H
2.76 1.04
4.9 1.5
2.79 1.07
4.87 1.32
31
32
H
H
H
H
4.02 1.08
4.42 1.12
4.00 1.08
4.5 1.33
33
H
H
4.56 1.51
4.78 1.34
34
35
H
H
H
H
4.89 1.41
4.92 1.45
4.91 1.3
4.98 1.7
(continued on next page)

8
S. Hameed et al. / European Journal of Medicinal Chemistry 183 (2019) 111677
Table 1 (continued )
Compounds
R1
R2
R3
a-Amylase Inhibition
a-Glucosidase Inhibition
IC50 SEMa
2.12 1.35
(m
M)
IC50 SEMa
(mM)
36
37
CH3
CH3
2.21 1.08
CH3
CH3
2.00 1.22
3.21 1.32
2.04 1.4
38
CH3
CH3
3.3 1.51
39
40
CH3
CH3
CH3
CH3
3.53 1.31
2.51 1.82
3.41 1.08
2.6 1.13
Standard ¼ Acarbose
SEMa (Standard error of mean); (Standard inhibitor for
1.98 1.04
2.00 1.11
a-amylase,
a-glucosidase inhibitory activity).
Fig. 7. General structure of synthetic benzotriazoles.
hydrophobic interactions with the active site of enzyme. Further-
M) bearing an additional
chlorine atom displayed increased activity as compared to com-
actively participated in the activity of molecules (Fig. 15), however,
slight variation in the activity is might be due to some variable
structural features which played important role in the enzyme in-
hibition. A limited structure-activity relationship (SAR) was devel-
oped based on the variable groups and their particular positions on
aryl ring. The synthetic compounds included in “Category A00 have
been composed of three different substituents on benzotriazole ring.
Amongst chloro substituted benzotriazole derivatives of “Category
more, compound 37 (IC50 ¼ 2.00 1.22
m
pound 36. Same activity pattern was observed when compared
with compound 26 (IC50 ¼ 3.89 1.09
mM) as it showed less
inhibitory activity than derivative 36. It further confirms the active
participation of methyl group at benzotriazole ring.
Replacing chloro with methoxy as in compound 40
(IC50 ¼ 2.51 1.82
m
M) resulted in slight decreased activity (Fig. 7).
38 M) and 39
(IC50 ¼ 3.21 1.32
M) having ortho hydroxy group at aryl ring and
A00, compound 10 (IC50 ¼ 3.7 1.3
mM) with unsubstituted aryl ring
exhibited good inhibitory activity. However, substitution on aryl part
Compounds
m
(IC50 ¼ 3.53 1.31
m
resulted in increased inhibitory activity as in compound
(IC50 ¼ 3.00 1.21 M) having chloro group at meta position might
be due to better interaction of chloro group with active site of
M) with two methyl
8
unsubstituted aryl part were least active which indicate their weak
interaction with active site of the enzyme (Fig. 14).
m
enzyme. Compound 9 (IC50 ¼ 3.82 1.42
m
substituents ortho to each other was less active as compared to
compound 8, might be the methyl groups are creating steric hin-
drance or their electron donating effect is negatively participating in
2.6. Structure-activity relationship (SAR) for
inhibitory activity
a-glucosidase
Compounds 7e24 of “Category A00 demonstrated good
sidase inhibitory activity in the range
IC50 ¼ 2.82 1.02e5.63 1.04
a
-gluco-
the activity. Compound 7 (IC50 ¼ 3.4 1.09
mM) with unsubstituted
aryl ring and methyl substituted benzotriazole ring displayed slight
of
good inhibition as compared to compound 10 (Fig. 15).
m
M. All the structural features have

S. Hameed et al. / European Journal of Medicinal Chemistry 183 (2019) 111677
9
Fig. 8. Structure-activity relationship (SAR) of compounds 7-10.
Fig. 9. Structure-activity relationship (SAR) of compounds 11-14.
Fig. 10. Structure-activity relationship (SAR) of compounds 15-19.

10
S. Hameed et al. / European Journal of Medicinal Chemistry 183 (2019) 111677
Fig. 11. Structure-activity relationship of compounds 20-24.
Fig. 12. Structure-activity relationship of compounds 25-29.
Fig. 13. Structure-activity relationship of compounds 30-35.
All other synthetic derivatives of this category are comprised of
unsubstituted benzotriazole ring. Among them the para fluoro
substituted compound 11 was found to be most active with IC50
and addition of flouro group resulted in two folds decreased ac-
M) might be the ortho
position is not favorable for the enzyme interaction. Adding chloro
tivity in compound 13 (IC50 ¼ 5.23 1.54
m
value of 2.82 1.02
mM and showed comparable activity to the
group along with two fluorine atoms in compound 12
standard acarbose (IC50 ¼ 2.20 1.11
mM). Changing the position
(IC50 ¼ 6.63 1.24
mM) resulted in further declined activity which

S. Hameed et al. / European Journal of Medicinal Chemistry 183 (2019) 111677
11
Fig. 14. Structure-activity relationship of compounds 36-40.
Fig. 15. Structure-activity relationship of compounds 7-10.
indicates that increasing number of substituents resulted in
decreased activity might be due to increased steric factor. Replacing
bromine with fluorine also resulted in decreased activity in com-
category (Fig. 18).
Benzotriazoles derivatives 25e40 belongs to “Category B". In
M) with para chloro
substitution was most active which showed that substitution at
para position is actively contributing in the activity. The di chloro
this category, compound 25 (IC50 ¼ 2.5 1.21
m
pound 14 (IC50 ¼ 3.2 1.12
Compounds 15e19 with methoxy and methyl substituents also
displayed variable inhibition against -glucosidase. Compound 15
(IC50 ¼ 2.99 1.08 M) with para methoxy group was more active
as compared to its ortho methoxy derivative 16
(IC50 ¼ 4.79 1.12 M) which showed that substituents at para
mM) (Fig. 16).
a
compounds 26 (IC50 ¼ 3.9 1.08
m
M) and 27 (IC50 ¼ 3.47 1.31
mM)
m
with different positions of chlorine at aryl ring showed many folds
decreased activity as compared to para chloro compound 25. It
showed that number and positions of the substituent played an
important role in exhibiting the inhibitory potential. Interestingly,
m
position are actively participating in the activity and helping in the
binding interactions of compounds with enzyme. However, methyl
substituted analogs were moderately active as compared to
methoxy substituted compounds. All three compounds 17
compound 28 (IC50 ¼ 2.79 1.07
mM) with para bromo substitution
displayed almost similar activity as compound 25. Changing the
position of bromine atom from para to meta as in compound 29
(IC50 ¼ 4.42 1.09
m
M), 18
(IC50 ¼ 4.8 1.12
m
M),
and
19
(IC50 ¼ 4.41 1.14
mM) resulted in decreased activity. It was expe-
(IC50 ¼ 4.23 1.07
mM) with mono, di, and trimethyl groups,
rienced that compounds with substituents having more negative
inductive effect such as Cl, and Br showed more potent inhibition
activity than the compounds with less negative inductive effect
(Fig. 19).
respectively, displayed almost similar activity which showed that
methyl groups are not actively participating in the activity (Fig. 17).
Compound 20 (IC50 ¼ 2.97 1.7
mM) with para-nitro substitu-
tion was second most active compound of “Category A". The
addition of methyl group adjacent to nitro as in compound 21
Compound 34 (IC50 ¼ 4.91 1.3
mM) with unsubstituted phenyl
ring was less active. However, compound 31 (IC50 ¼ 4.00 1.08
m
M)
(IC50 ¼ 4.1 1.23
showed that methyl group are less participating in the activity.
Compound 22 (IC50 ¼ 4.32 1.23 M) having one chloro and amino
group was placed ortho to each other was found to be less active
m
M) resulted in decreased activity which again
bearing a meta nitro group exhibited good activity as compared to
compound 34. Replacing nitro group with para methoxy as in
m
compound 32 (IC50 ¼ 4.5 1.33
be due to the electron donating nature of the substituent. Com-
M) with para methyl resulted in
mM) resulted in less activity might
against
a-glucosidase
enzyme.
Compounds
23
pound 33 (IC50 ¼ 4.78 1.34
m
(IC50 ¼ 5.6 1.11
m
M) and 24 (IC50 ¼ 5.29 1.3
m
M) with butoxy and
decreased activity as compared to methoxy substituted analog
which showed that might be methoxy group is interacting with the
unsubstituted phenyl ring were least active molecules of this

12
S. Hameed et al. / European Journal of Medicinal Chemistry 183 (2019) 111677
Fig. 16. Structure-activity relationship of compounds 11-14.
Fig. 17. Structure-activity relationship of compounds 15e19.
Fig. 18. Structure-activity relationship of compounds 20-24.
active site of enzyme through hydrogen bonding. Replacing methyl
with phenyl ring resulted in further declined activity as in com-
As the results obtained in case of
comparison of compound 36 with 25 (IC50 ¼ 2.5 1.21
revealed that methyl substitutions are playing some role in the a-
a
-amylase inhibition, activity
mM)
pound
35
(IC50 ¼ 4.98 1.7
m
M).
Compounds
30
(IC50 ¼ 4.87 1.32
m
M) with ortho hydroxy group also displayed
glucosidase
inhibition.
Similarly,
compound
37
decreased activity (Fig. 20).
(IC50 ¼ 2.04 1.4
mM) with an additional chloro atom showed good
a-glucosidase inhibition, however, it was better active as compared
Compounds 36e40 were composed of methyl substituted ben-
zotriazole ring, among them compound 36 (IC50 ¼ 2.21 1.08
m
M)
to compound 36. Compound 38 (IC50 ¼ 3.3 1.51
m
M) having ortho
with para chloro substitution was found to be significantly active.
hydroxy group was found to be less active as compared to chloro

S. Hameed et al. / European Journal of Medicinal Chemistry 183 (2019) 111677
13
Fig. 19. Structure-activity relationship of compounds 25-29.
Fig. 20. Structure-activity relationship of compounds 30e35.
substituted analogs. When para position was substituted with an
electron-donating methoxy group in compound 40
(IC50 ¼ 2.6 1.13 M) showed comparable activity to the standard
acarbose, however, derivative 39 (IC M) with
unsubstituted phenyl ring showed a weak inhibition activity as
compared to other active compounds (Fig. 21) (see Fig. 22 and 23).
enzyme kinetic software. By using various kinetics plots such as
Lineweaver-Burk, Hill, Hanes-Woolf, Eadie- Hofstee, Dixon and
Scatchard models, the kinetic parameters Vmax, Km, AICc and R2
values were calculated (Table-3). Based on curve fitting model and
low AICc value, the kinetic studies results shown that all selected
compounds followed non-competitive type of inhibition mecha-
nism (Fig. 25).
m
¼ 3.41 1.08
m
50
2.7. Kinetic characterization of
a-amylase inhibition
2.9. Molecular docking (MD) studies
Kinetic studies on the most active
a-amylase inhibitors 40, 37,
36, 25, 29, 11, 20, 15, and 8 were analyzed to interpret the inhibition
mechanism of these compounds The mechanism of enzyme inhi-
bition was analyzed by graph fitting analysis using Sigma-Plot
enzyme kinetic software. By using various kinetics plots such as
Hanes-Woolf, Lineweaver-Burk, Hill, Scatchard, Eadie-Hofstee, and
Dixon models, the kinetic parameters Km, AICc, Vmax, and R2
values were calculated (Table-2). Based on curve fitting model and
low AICc value, the kinetic studies results shown that all selected
compounds following competitive type inhibitors mechanism
(Fig. 24).
2.9.1.
a-Amylase molecular study
The MD approach was performed in-order to explore the
possible binding mechanism of the competitive inhibitors against
the
a-amylase enzyme. The MD results revealed that all the in-
hibitors bind well to substrate binding site with various affinity.
Based on visual inspection and PL interaction profile of all the in-
hibitors demonstrates that mostly, potent inhibitors possess elec-
tron withdrawing group in di or mono passion over benzene ring,
the di-EWG groups (di-Cl) in compound 37 (IC50 ¼ 2.00 1.22
mM)
showed best fit-well pattern of PL interaction profile and remain
tight in the active site; the PL interaction profile includes residue
Lys200, Ile235, His201, Tyr151, Asp300 as shown in Fig. 26A. The
high potency of compound 37 might be due to the attached EWG
di-Cl at -para and -meta position which readily draws electrons
away from a reaction center, when this center is an electron rich
carbanion, the presence of the electron-withdrawing substituent
has a stabilizing effect, hence enhance the enzyme activity. In case
2.8. Kinetic characterization of
a-glucosidase inhibition
Kinetic studies on the most active
a-glucosidase inhibitors 40,
31, 30, 19, 23, 7, 14, 9, and 8 were analyzed to interpret the inhi-
bition mechanism of these compounds. The mechanism of enzyme
inhibition was analyzed by graph fitting analysis using Sigma-Plot

14
S. Hameed et al. / European Journal of Medicinal Chemistry 183 (2019) 111677
Fig. 21. Structure-activity relationship of compounds 36-40.
a-amylase and a
-glucosidase activities of “Category A00
Fig. 23. Comparison of
a-amylase and a
-glucosidase activities of “Category B00
Fig. 22. Comparison of
compounds.
compounds.
Table 2
Kinetic studies of active compounds for a-amylase inhibition.
S. No.
Compound No.
Vmax (
m
M/min)1
Km (mM)
AICc
R2
Type of inhibition
1
2
3
4
5
6
7
8
9
40
37
36
25
29
11
20
15
8
505.1
593.3
514.4
527.0
512.5
522.2
511.6
554.0
514.5
0.20
0.24
0.18
0.20
0.21
0.19
0.20
0.21
0.20
202.4
214.2
210.1
202.8
208.2
210.8
230.2
220.4
230.5
0.912
0.924
0.920
0.910
0.914
0.902
0.914
0.908
0.914
Competitive type
Competitive type
Competitive type
Competitive type
Competitive type
Competitive type
Competitive type
Competitive type
Competitive type
of other top 3 out of 4 active inhibitors including 29, 23, 31 in the
series adopt side chain donor and acceptor hydrogen interaction
with residue Ile235, Glu233, Lys200, His201 (Fig. 26B-D). All these
inhibitors possess the same EWG but the only differences found in
position of attachment with mono-passion. As the position of the
attached groups and their quantity (from mono to di or di to mono
group) change ultimately reduce the catalytic activity. Overall, the
MD study results demonstrate that the inhibitors possess higher
number of attached groups over benzene showed not only high
potency but as well as showed high potency experimentally. The
detail protein-ligand interaction profile listed in Table-4.
glucosidase enzyme. Generally, the enlisted compounds possess
different substituted groups, e.g., some possess electron with-
drawing groups (EWG) and some have electron donating groups
(EDG). The docking results revealed that the number of functional
groups (mono to di or di to mono), position, and the variation in the
substituted groups from one to another or vice versa eventually
altered the enzyme activity. Subsequently, the MD results revealed
that all the derivatives participated well in the binding with the
catalytic residues that play a vital role in enhancing or reducing the
activity of the enzyme. The MD resulted in further exploration of
the binding pattern of all active compounds and were found well
accommodated in the active site of the enzyme. The active com-
pounds including compounds 37, 36, 25, 40, and 29 which ranked
1e5 in the series mainly showed significant interactions with the
catalytic residues in the active sites of enzyme, respectively. The in-
2.9.2.
Molecular docking (MD) approach was performed to explore the
possible binding mode of the synthetic derivatives against the
a-Glucosidase molecular study
a-

S. Hameed et al. / European Journal of Medicinal Chemistry 183 (2019) 111677
15
Fig. 24. A) Lineweaver-Burk plot of 1/[S] Vs 1/Rate in the different concentration of mixed-type inhibitor. B) Hill plot of different concentration of [S] Vs Rate (Vmax-Rate) in the
different concentration of mixed-type inhibitor. Fig. 24: C) Hanes-Woolf plot of compound 8 at different concentration of [S] Vs [S]/Rate in the different concentration of mixed-type
inhibitor. D) Eadie-Hofstee plot of compound 8 by rate/[S] Vs Rate in the different concentration of mixed-type inhibitor. Fig. 24: E) Dixon plot of compound 8 at different con-
centration of mixed inhibitor Vs 1/Rate. F) Scatard plot of compound 8 by Rate Vs Rate/[S] in the different concentration of mixed-type inhibitor.
depth protein-ligand interaction analysis for the most active com-
pound 37 (IC50 ¼ 2.04 1.04 M) demonstrates and support the
high potency against -glucosidase enzyme adopt most favorable
interactions with active site catalytic residues, e.g., Glu276, Asp349,
Asp408 and His245 (Fig. 27A). The high potency might be due to the
attached EWG (di-Cl) and has more inductive effect as compare to
compounds 36, 25 and 29 which possess the same group at -para
position but showed less activity (Fig. 27D). The low activity of
these compounds as compared with the most potent compound 37
might be due to the quantity of the EWG and as well the position. In
case of 2nd most active compound 25 which showed high activity
than compound 29, even though possess substituting group at
-para position. The difference might be due to the inductive effect;
the Cl have high than the Br.
Additionally, the compound Cl (3.16) have high electronegativity
compared with Br (2.96). Based on the characteristics as mentioned
earlier, the Cl tend to withdraw electron more efficiently than Br
and hence enhance the enzyme activity. Moreover, similar protein-
m
a

16
S. Hameed et al. / European Journal of Medicinal Chemistry 183 (2019) 111677
Table 3
Kinetic studies of active compounds for
a-glucosidase inhibition.
S. No.
Compound No
Vmax (
m
M/min)1
Km (mM)
AICc
R2
Type of inhibition
1
2
3
4
5
6
7
8
9
40
31
30
19
23
7
14
9
8
620.1
618.4
601.2
612.5
620.8
602.2
612.5
620.2
620.3
0.21
0.26
0.25
0.20
0.24
0.20
0.20
0.24
0.25
210.1
203.3
212.0
221.3
205.4
211.5
214.2
218.1
205.4
0.902
0.914
0.925
0.940
0.912
0.951
0.926
0.902
0.940
Non-competitive type
Non-competitive type
Non-competitive type
Non-competitive type
Non-competitive type
Non-competitive type
Non-competitive type
Non-competitive type
Non-competitive type
ligand interaction profile was observed for other compounds, the
only difference found in their activities might be due to residues
interaction some interact with catalytic site residues and some with
arbitrary residues in the active site which are less role in enhancing
or reducing the enzyme activity, respectively.
4.2. Kinetic study assay
4.2.1.
To determine the mechanism of enzyme inhibition, the kinetic
studies were performed by using varying concentration of
a-Amylase inhibition assay
a
-
Overall from the molecular docking approach, it was observed
that all the derivatives showed enough favorable interactions. The
observed gradual decreased in docking score as well as in the mode
of interaction of each compound may be based on the attached
electron withdrawing and donating groups, and hence partici-
pating in decreasing or enhancing the inhibition activity of the
enzymes. The detail protein-ligands interaction profile listed in
Table-5.
amylase inhibitors (0.0625, 0.125, 0.3 and 0.4 mM) with varying
concentrations of inhibitor substrate (p-nitrophenyl-R-D-maltoside
(NPM)) such as 0.1, 0.2, 0.4, 0.8, and 1.0 mM. The enzyme was dis-
solved in de-ionized water to produce the concentration 0.2 mg/mL
for each well. PIPES buffer was to adjusted the pH at 7.0, the re-
action mixture was incubated for the period of 30 min at 25 ꢀC. The
absorbance was measured using ELISA reader by keeping the 96-
well plate (BioTek XL-800, USA). The kinetic parameters Vmax,
Km, AICc and R2 values of all the
a-amylase inhibitor activities were
determined by graph fitting analysis using Sigma-Plot enzyme ki-
3. Conclusion
netic software 14.0 version [24,25].
Thirty four benzotriazoles derivatives (7e40) were synthesized
by reacting benzotriazoles with different substituted benzoic acids
and phenacyl bromides. The synthetic compounds were evaluated
4.2.2.
To determine the mechanism of
tion, the kinetic studies were performed by using varying concen-
tration of -glucosidase inhibitors (0.0625, 0.125, 0.3 and 0.4 mM)
with varying concentrations of inhibitor substrate (p-nitrophenyl
R-D-maltoside (NPM)) such as 0.1, 0.2, 0.4, 0.8 and 1.0 mM. The
enzyme was dissolved in de-ionized water to produce the con-
centration 0.2 mg/mL for each well. PIPES buffer was used as
adjusted the pH of 7.0. the reaction mixture was incubated for the
period of 30 min at 25 ꢀC for 1-min interval. The absorbance was
measured using ELISA reader by keeping the 96-well plate (BioTek
XL-800, USA). The kinetic parameters Vmax, Km, AICc and R2 values
a-Glucosidase inhibition assay
a-glucosidase enzyme inhibi-
for
pounds displayed good to moderate inhibitory activities in the
range of IC50 values of 2.00 1.22e5.72 1.12 and
2.04 1.4e5.6 1.11 M against -amylase and -glucosidase en-
a-glucosidase and a-amylase inhibitory activities. All com-
a
m
a
a
zymes, respectively. In order to understand better structure-
activity relationship the synthetic compounds were divided into
two categories A and B. Out of thirty four compounds, eight com-
pounds 8, 11, 15, 20, 25, 29, 36, and 40 displayed good inhibitory
activities. These compounds displayed almost similar activity
against a-amylase and a-glucosidase enzyme, thus found to have
dual inhibitory activity. Molecular docking studies of most active
compounds revealed that different substitutions at aryl ring are
playing important roles in the binding interactions. The kinetic
studies revealed that the synthetic molecules have shown
of all the a-glucosidase inhibitors were determined by graph fitting
analysis using Sigma-Plot enzyme kinetic software 14.0 version
[25].
competitive mode of inhibition against
a-amylase and non-
4.2.3.
The
modified from Kwon, Apostolidis and Shetty. A volume of 500
-amylase solution (0.5 mg/mL) in 0.2 mM phosphate buffer (pH
6.9) and 500 L of test sample (100, 200, 400, 800, 1000 g/mL)
were incubated for 10 min at 25 ꢀC. After pre-incubation, 1% starch
solution (500 L) in 0.02 M sodium phosphate buffer (pH 6.9) was
a
-Amylase inhibition assay
-amylase inhibitory activity was determined by an assay
L of
competitive mode of inhibition against
a-glucosidase enzyme.
a
m
4. Experimental
a
m
m
4.1. Materials and methods
m
Thin layer chromatography was carried out on pre-coated silica
gel, GF-254 (Merck, Germany). Spots were visualized under ultra-
violet light at 254, 366 nm or iodine vapors. EI- and HREI-MS
spectra were recorded on MAT 312 and MAT 113D mass spec-
trometers. The 1H, 13C NMR were recorded on a Bruker AM spec-
trometers, operating at 300 and 400 MHz. The chemical shift values
added to each tube and incubated at 25 ꢀC for 10 min. 1 mL of
dinitrosalicylic acid color reagent was then added to the reaction
mixture and the tubes were incubated in boiling water for 5 min,
and finally cooled to room temperature. The solutions were diluted
by adding 10 mL distilled water and the absorbance was measured
at 540 nm [9]. The percentage inhibition was calculated as
illustrated,
are presented in ppm (d), relative to tetramethylsilane (TMS) as an
internal standard and the coupling constant (J) are in Hz. Melting
points of the compounds were determined on a Stuart® SMP10
melting point apparatus and are uncorrected.
% Inhibition ¼ (Absorbance Control e Absorbance Sample)/Absorbance
Control ꢁ
100

S. Hameed et al. / European Journal of Medicinal Chemistry 183 (2019) 111677
17
Fig. 25. A) Lineweaver-Burk plot of 1/[S] Vs 1/Rate in the different concentration of Competitive-type inhibitor. B) Hill plot of different concentration of [S] Vs Rate (Vmax-Rate) in
the different concentration of Competitive-type inhibitor. Fig. 25 C) Hanes-Woolf plot of compound 8 at different concentration of [S] Vs [S]/Rate in the different concentration of
competitive -type inhibitor. D) Eadie-Hofstee plot of compound 8 by rate/[S] Vs Rate in the different concentration of Competitive -type inhibitor. Fig. 25 E) Dixon plot of compound
8 at different concentration of Competitive Inhibitor Vs 1/Rate. F) Scatard plot of compound 8 by Rate Vs Rate/[S] in the different concentration of Competitive -type inhibitor.
the crystallographic structure yet. Later, the model was subjected
for 3D protonation, and the energy was minimized till 0.05
Gradient using MMFF94s force field implemented in MOE. Next, the
3D structures for all derivatives were built using the Molecular
4.3. Molecular docking protocol
Builder Module implemented in MOE. All the derivatives were set
flexible, in order to obtain the minimal energy complex during the
MD. Later, the docked complexes were ranked based on the docking
scores (S). Finally, the predicted ligand-protein complexes were
Molecular docking (MD) approach was performed using MOE-
dock module implemented in the Molecular Operating Environ-
ment (MOE) software package [26] to dock all the synthetic de-
rivatives against the
a-glucosidase enzyme. We used the homology
analyzed for molecular interactions using PyMol v1.7.
model described by Guerreiro et al. [27] due to the unavailability of

18
S. Hameed et al. / European Journal of Medicinal Chemistry 183 (2019) 111677
Fig. 26. (A) The binding mode of the most potent compound 37, (B) for compound 29, (C) for compound 23, and (D) for compound-31.
4.4. Spectral data of synthetic compounds (7e40)
4.4.4. (5,6-Dichloro-1H-benzo[d][1,2,3]triazol-1-yl)(phenyl)
methanone (10) [CAS # 72435-62-2]
4.4.1. (5,6-Dimethyl-1H-benzo[d][1,2,3] triazol-1-yl)(phenyl)
methanone (7) [CAS # 500288-41-5]
Solid: Yield: 72%; M.p.: 160e163 ꢀC; 1H NMR (300 MHz,
0 0
DMSO‑d6):
d 8.77 (s, 1H, H-1), 8.52 (s, 1H, H-2), 8.12 (d, J2 ,3 /
Solid: Yield: 62%; M.p.: 142e146 ꢀC; 1H NMR (300 MHz,
¼ 7.2 Hz, 2H, H-2 , H-6 ), 7.81 (t, J4 ,3 /4 ,5 ¼ 7.5 Hz, 1H, H-4 ), 7.68
0
0
0
60,50
0
0
0
0
DMSO‑d6): d
8.11 (ovp, 3H, H-20, H-60, H-1), 8.03 (s, 1H, H-2), 7.78 (t,
(t, J 3 (2 ,4 )/5 (4 ,6 ) ¼ 7.8 Hz, 2H, H-30, H-50), EI-MS m/z (% rel. abund.):
0
0
0
0
0
0
J4,3/4,5 ¼ 7.5 Hz, 1H, H-40), 7.65 (t, J3 (2 ,4 )/5 (4 ,6 ) ¼ 7.8 Hz, 2H, H-30, H-
50), 2.47 (s, 3H, CH3), 2.42 (s, 3H, CH3), EI-MS m/z (% rel. abund.): 251
[Mþ, 17], 223 (55), 105 (100), 77 (52), Anal. Calcd for C15H13N3O:
C ¼ 71.70; H ¼ 5.21; N ¼ 16.72; O ¼ 6.37; Found: C ¼ 71.65;
H ¼ 5.13; N ¼ 16.85; O ¼ 6.35.
291 [Mþ, 10], 293 (Mþþ2, 7),263 (54), 105 (100), 77 (100), 51 (27);
0
0
0
0
0
0
Anal. Calcd for
C
13H7Cl2N3O: C ¼ 53.45; H ¼ 2.42; Cl ¼ 24.27;
N ¼ 14.38; O ¼ 5.48; Found: C ¼ 53.41; H ¼ 2.39; Cl ¼ 24.24;
N ¼ 14.36; O ¼ 5.45.
4.4.5. (1H-Benzo[d][1,2,3]triazol-1-yl)(4-fluorophenyl)methanone
(11) [CAS # 203070-37-5]
4.4.2. (3-Chlorophenyl)(5,6-dichloro-1H-benzo[d][1,2,3] triazol-1-
yl)methanone (8)
Solid: Yield: 61%; M.p.: 100e101 ꢀC; 1H NMR (300 MHz,
DMSO‑d6):
d
8.35 (t, J2,3/6,5 ¼ 9.0 Hz, 2H, H-20, H-60), 7.95 (ovp, 3H,
Solid: Yield: 53%; M.p.: 157e162 ꢀC; 1H NMR (300 MHz,
0
0
H-30, H-50, H-1), 7.71 (t, J3(2,4) ¼ 9.0 Hz, 1H, H-3), 7.52 (ovp ¼ 2H, H-
2, H-4), EI-MS m/z (% rel. abund.): 241 [Mþ, 7], 213 (67), 123 (100),
95 (37); Anal. Calcd for C13H8FN3O: C ¼ 64.73; H ¼ 3.34; F ¼ 7.88;
N ¼ 17.42; O ¼ 6.63; Found: C ¼ 64.71; H ¼ 3.31; F ¼ 7.85;
N ¼ 17.40; O ¼ 6.60.
DMSO‑d6):
60,40
d
8.79 (s, 1H, H-1, CH), 8.51 (s, 1H, H-4, CH)0, 8.12 (t, J6 ,2 /
¼1.8 Hz, 1H, H-60), 8.06 (d, J
¼ 7.8 Hz, 1H, H-2 ), 7.87 (dd, J
0
0
2 ,3
0
40,30
0
0
0
0
0
0
¼ 7.2 Hz, J 4 ,6 ¼ 1.2 Hz, 1H, H-4 ), 7.71 (t, J3 ,2 /3 ,4 ¼ 8.1 Hz,1H, H-
30); 13C NMR (100 MHz, DMSO‑d6):
d
c 166.0, 157.1, 144.1, 139.2,
136.6, 133.2, 132.9, 132.6, 130.6, 129.2, 128.7, 127.8, 116.6; EI-MS m/z
(% rel. abund.): 325 [Mþ, 14], 327 (Mþþ2, 12), 329 (Mþþ4, 4.2), 297
(52), 139 (100), 111 (50), 75 (23), HREI-MS Calcd for C13H6Cl3N3O m/
z 324.96 found is 325.96; Anal. Calcd for C13H6Cl3N3O: C ¼ 47.81;
H ¼ 1.85; Cl ¼ 32.57; N ¼ 12.87; O ¼ 4.90; Found: C ¼ 47.78;
H ¼ 1.82; Cl ¼ 32.55; N ¼ 12.85; O ¼ 4.88.
4.4.6. (1H-Benzo[d][1,2,3]triazol-1-yl)(2-chloro-3,4-
difluorophenyl)methanone (12)
Solid: Yield: 63%; M.p.: 100e101 ꢀC; 1H NMR (300 MHz,
DMSO‑d6): d
8.35 (ovp, 2H, H-20, H-30), 8.22 (ovp, 1H, H-1), 8.08 (dd,
J4,3 ¼ 7.2 Hz, J 4,2 ¼ 3.3 Hz, 1H, H-3), 7.92 (t, J3(2,4) ¼ 8.1 Hz, 1H, H-3),
7.73 (t, J2(1,3) ¼ 8.1 Hz, 1H, H-2); 13C NMR (75 MHz, DMSO‑d6):
dc
4.4.3. (5,6-Dichloro-1H-benzo[d][1,2,3] triazol-1-yl)(3,4-
dimethylphenyl)methanone (9)
165.1, 131.4, 130.5, 127.3, 123.5, 120.4, 119.9, 119.8, 119.6, 119.5, 119.1,
114.4, 113.9; EI-MS m/z (% rel. abund.): 293 [Mþ, 31], 295 (Mþþ2,
10), 265 (77), 175 (100), 147 (46); Anal. Calcd for C13H6ClF2N3O:
C ¼ 53.17; H ¼ 2.06; Cl ¼ 12.07; F ¼ 12.94; O ¼ 5.45; Found:
C ¼ 53.14; H ¼ 2.03; Cl ¼ 12.04; F ¼ 12.91; O ¼ 5.42.
Solid: Yield: 52%; M.p.: 143e148 ꢀC; 1H NMR (300 MHz,
DMSO‑d6):
H-20 H-30),7.42 (s, 1H, H-60, CH), 2.38 (s, 6H, CH3); 13C NMR
(100 MHz, DMSO‑d6): c 166.1, 144.2, 137.7, 135.3, 134.1, 133.8, 131.1,
d 8.76 (s,1H, H-1, CH),8.48 (s,1H, H-2, CH), 7.66 (br. s, 2H,
d
130.7, 129.3, 128.9, 126.9,121.4, 115.7, 20.7, 20.6; EI-MS m/z (% rel.
abund.): 319 (Mþ, 26), 321 (Mþþ2, 16), 323 (Mþþ4, 3), 291 (44), 133
(100), 105 (79), 77 (27); Anal. Calcd for C15H11Cl2N3O: C ¼ 56.27;
H ¼ 3.46; Cl ¼ 22.14; N ¼ 13.12; O ¼ 5.00; Found: C ¼ 56.23;
H ¼ 3.43; Cl ¼ 22.10; N ¼ 13.15; O ¼ 4.88.
4.4.7. (1H-Benzo[d][1,2,3]triazol-1-yl)(2,6-difluorophenyl)
methanone (13) [28]
Solid: Yield: 77%; M.p.: 131e133 ꢀC; 1H NMR (300 MHz,
DMSO‑d6):
d
8.36 (dd, J1,2/4,3 ¼ 8.1 Hz, J 1,3/4,2 ¼ 3.3 Hz, 2H, H-1, H-4),

S. Hameed et al. / European Journal of Medicinal Chemistry 183 (2019) 111677
19
Table 4
Protein Ligand Interaction profile.
S. No
Interaction details
Docking score
Ligands
Receptor
Distance
E cal/mol
Residue
7
8
O 17
6-ring
Cl 25
N 10
O 14
5-ring
O 20
6-ring
N 9
6-ring
5-ring
N 8
6-ring
5-ring
N 9
N 8
N 9
6-ring
5-ring
N 8
N 9
O 12
N 8
NE2
CD1
OG1
NE2
NH2
6-ring
CB
CD1
CE
CE2
CD1
NZ
H-acceptor
-H
H-donor
H-acceptor
H-acceptor
p-p
3.11
3.72
3.30
3.35
3.13
4.00
3.45
3.82
3.49
3.52
3.61
3.19
3.62
3.67
3.75
3.23
3.51
3.57
3.70
3.69
3.12
2.72
3.27
3.49
3.34
3.77
3.21
3.95
3.47
3.38
3.67
3.51
4.06
3.11
3.59
3.10
3.23
3.49
3.52
3.61
3.21
3.26
3.48
3.48
3.11
3.32
3.19
3.49
3.54
3.46
3.58
3.55
3.73
4.21
3.68
3.23
3.51
3.57
3.70
3.52
2.84
3.33
3.70
3.75
3.90
3.74
3.65
3.69
3.12
2.72
3.43
3.80
ꢂ1.5
ꢂ0.7
ꢂ1.2
ꢂ1.0
ꢂ5.2
ꢂ0.0
ꢂ0.5
ꢂ0.6
ꢂ0.5
ꢂ0.7
ꢂ0.8
ꢂ7.3
ꢂ0.8
ꢂ0.8
ꢂ2.2
ꢂ8.7
ꢂ0.5
ꢂ0.7
ꢂ0.7
ꢂ0.5
ꢂ1.7
ꢂ2.5
ꢂ4.8
ꢂ1.3
ꢂ0.6
ꢂ0.5
ꢂ7.8
ꢂ0.8
ꢂ0.8
ꢂ0.5
ꢂ0.8
ꢂ2.3
ꢂ0.5
ꢂ4.4
ꢂ0.6
ꢂ2.0
ꢂ8.7
ꢂ0.5
ꢂ0.7
ꢂ0.8
ꢂ3.4
ꢂ3.0
ꢂ1.7
ꢂ2.7
ꢂ3.5
ꢂ0.6
ꢂ8.6
ꢂ0.5
ꢂ0.6
ꢂ0.8
ꢂ0.5
ꢂ2.5
ꢂ0.6
ꢂ0.8
ꢂ0.7
ꢂ8.7
ꢂ0.5
ꢂ0.7
ꢂ0.7
ꢂ0.6
ꢂ3.2
ꢂ0.6
ꢂ1.0
ꢂ0.5
ꢂ0.5
ꢂ0.6
3.65
HIS201
ILE235
THR163
HIS299
ARG195
TYR62
ꢂ4.52
ꢂ5.53
p
9
H-acceptor
-H
H-acceptor
TRP59
ꢂ5.58
p
ILE235
LYS200
HIS201
ILE235
LYS200
HIS201
ILE235
ARG195
LYS200
LYS200
HIS201
ILE235
GLN63
THR163
THR163
ARG195
ARG195
ALA198
ILE235
LYS200
ARG195
HIS299
ALA198
ARG195
ARG195
ARG195
LYS200
LYS200
ILE235
LYS200
LYS200
HIS201
ILE235
LYS200
LYS200
ARG195
ARG195
LYS200
LYS200
LYS200
LYS200
HIS201
ASP300
TYR62
10
p
p
-H
-H
ꢂ4.47
ꢂ5.12
11
H-acceptor
NE2
CD1
NH2
NZ
p
p
-H
-H
12
13
H-acceptor
H-acceptor
H-acceptor
ꢂ5.23
ꢂ5.09
CE
CE2
CD1
O
O
O
NH2
NH2
NZ
CD1
NZ
NH2
NE2
CB
NH2
NH2
NH2
NZ
CE
N
NZ
CE
CE2
CD1
NZ
p
p
-H
-H
14
15
H-donor
H-donor
H-donor
H-acceptor
H-acceptor
H-acceptor
ꢂ5.07
ꢂ4.94
N 9
O 12
6-ring
N 9
N 8
N 9
O 12
N 8
N 9
16
17
18
p
-H
ꢂ4.56
ꢂ5.07
H-acceptor
H-acceptor
H-acceptor
H-acceptor
H-acceptor
H-acceptor
H-acceptor
H-acceptor
H-acceptor
H-acceptor
H-acceptor
H-acceptor
ꢂ4.95
ꢂ5.72
19
20
N 9
O 19
O 20
O 20
N 8
ꢂ5.83
ꢂ5.67
21
N 9
6-ring
5-ring
N 8
N 9
N 8
N 9
N 8
N 9
N 8
p
p
-H
-H
22
23
24
25
H-acceptor
H-acceptor
H-acceptor
H-acceptor
H-acceptor
H-acceptor
H-acceptor
H-acceptor
ꢂ4.74
ꢂ5.86
ꢂ5.29
ꢂ5.48
NZ
NH2
NH2
NZ
NZ
NZ
N 9
CE
6-ring
C 10
C 16
5-ring
6-ring
C 15
6-ring
N 8
NE2
OD2
6-ring
NE2
CD1
6-ring
CD1
NZ
p
-H
H-donor
H-
26
27
ꢂ5.71
ꢂ6.12
ꢂ5.79
p
p
p
-H
-H
HIS201
ILE235
TYR62
28
29
H-
H-
p
p
ILE235
LYS200
LYS200
HIS201
ILE235
GLU233
ASP197
ASP197
ILE235
ILE235
ALA198
ILE235
HIS201
GLN63
THR163
THR163
GLU233
ILE235
H-acceptor
H-acceptor
N 9
CE
ꢂ5.53
ꢂ5.56
6-ring
5-ring
C 10
O 19
O 19
5-ring
5-ring
N 8
5-ring
5-ring
C6A 6
O4A 9
O6A 11
C 10
5-ring
NE2
CD1
OE1
OD1
CE
OD1
CD1
CB
CD1
NE2
OE1
O
p
p
-H
-H
30
H-donor
H-donor
H-donor
p
p
-H
-H
31
32
33
34
35
ꢂ6.02
ꢂ5.71
ꢂ5.22
ꢂ5.30
H-acceptor
pi-H
p
-H
H-donor
H-donor
H-donor
H-donor
ꢂ0.5
ꢂ1.7
ꢂ2.5
ꢂ0.6
ꢂ0.8
ꢂ5.54
ꢂ5.90
O
OE1
CD1
36
p
-H
(continued on next page)

20
S. Hameed et al. / European Journal of Medicinal Chemistry 183 (2019) 111677
Table 4 (continued )
S. No
Interaction details
Ligands
Docking score
Receptor
Distance
E cal/mol
Residue
37
O
O
NZ
H-acceptor
H-acceptor
3.25
3.01
3.99
4.1
ꢂ11.6
ꢂ2.4
ꢂ0.5
ꢂ0.5
ꢂ0.7
ꢂ0.5
ꢂ1.7
ꢂ2.5
ꢂ0.5
ꢂ3.4
ꢂ1.3
ꢂ0.5
ꢂ0.5
ꢂ1.3
LYS200
HIS201
ILE235
TYR151
ASP300
GLN63
THR163
THR163
GLN63
GLU233
ASP197
ASP300
ILE235
ASP197
ꢂ5.34
NE2
CD1
6-ring
OD2
OE1
O
5-ring
6-ring
6-ring
C6A 6
O4A 9
O6A 11
C6A 6
C1H
C2H
C3H
5-ring
C2H 34
p
p
p
-H
-p
-H
3.9
38
39
H-donor
H-donor
H-donor
H-donor
H-donor
H-donor
H-donor
H-donor
H-donor
3.69
3.12
2.72
3.69
3.02
2.90
3.01
3.02
2.90
ꢂ5.90
ꢂ5.56
O
OE1
OE1
OD1
OD2
OE1
OD1
40
ꢂ5.43
Fig. 27. The ligand-protein interaction (LPI) profile for synthesized derivatives against the
a-glucosidase enzyme. The surface representation (left side) of the
a-glucosidase enzyme
in complex with most active compounds. The double-sided arrow represents pi-stacking interaction. The binding mode of the most potent compound (A) for compound 37, (B)
compound 36, (C) for compound 25, and (D) for compound 29.
7.93 (ovp, 2H, H-3, H-40), 7.74 (t, J2(1,3) ¼ 7.8 Hz,1H, H-2), 7.46 (t, J5 ,4 /
C ¼ 66.40; H ¼ 4.38; N ¼ 16.59; O ¼ 12.63; Found: C ¼ 66.38;
H ¼ 4.36; N ¼ 16.56; O ¼ 12.61.
0
0
¼ 8.7 Hz, 2H, H-30, H-50), EI-MS m/z (% rel. abund.): 259 [Mþ, 22],
30,40
231 (86), 203 (27), 141 (100), 113 (60), 63 (28); Anal. Calcd for
C
13H7F2N3O: C ¼ 60.24; H ¼ 2.72; F ¼ 12.66; N ¼ 16.21; O ¼ 6.17;
Found: C ¼ 60.21; H ¼ 2.70; F ¼ 12.63; N ¼ 16.19; O ¼ 6.16.
4.4.10. (1H-Benzo[d] [1,2,3]triazol-1-yl)(2-methoxyphenyl)
methanone (16) [28]
4.4.8. (1H-Benzo[d][1,2,3]triazol-1-yl)(4-bromophenyl)methanone
(14) [29]
Solid: Yield: 52%; M.p.: 95e96 ꢀC; 1H NMR (300 MHz, DMSO‑d6),
d
8.30 (ovp, 2H, H-1, H-4), 7.85 (t, J3(2,4) ¼ 7.8 Hz, 1H, H-3), 7.68 (ovp,
Solid; Yield: 81%; M.p.: 138e140 ꢀC; 1H NMR (300 MHz,
3H, H-2, H-40, H-50), 7.27 (d, J2 ,3 ¼ 8.1 Hz, 1H, H-2 ), 7.17 (t,
0
0
0
0
0
0
0
DMSO‑d6):
d
8.33 (ovp ¼ , 2H, H-1, H-4), 8.06 (d, J2 ,3 /6 ,5 ¼ 7.8 Hz,
J3 (2 ,4 ) ¼ 7.5 Hz, 1H, H-30), 3.71 (s, 3H, OCH3), EI-MS m/z (% rel.
abund.): 253 [Mþ, 80], 224 (89), 196 (31), 135 (100), 92 (50), 77 (77),
64 (24); Anal. Calcd for C14H11N3O2: C ¼ 66.40; H ¼ 4.38; N ¼ 16.59;
O ¼ 12.63; Found: C ¼ 66.38; H ¼ 4.36; N ¼ 16.56; O ¼ 12.61.
0
0
0
2H, H-20, H-60), 7.68 (ovp, 3H, H-1, H-50, H-30), 7.68 (J2(1,3) ¼ 7.8 Hz,
1H, H-2), EI-MS m/z (% rel. abund.): 301 (Mþ 2, 7.8), 275 (71), 183
(100), 157 (35), 119 (32), 91 (21), 64 (20); Anal. Calcd for
C
13H8BrN3O: C ¼ 51.68; H ¼ 2.67; Br ¼ 26.45; N ¼ 13.19; O ¼ 5.30;
Found: C ¼ 51.65; H ¼ 2.63; Br ¼ 26.42; N ¼ 13.16; O ¼ 5.28.
4.4.9. (1H-Benzo[d][1,2,3]triazol-1-yl)(4-methoxyphenyl)
methanone (15) [CAS # 4231-69-0]
4.4.11. (1H-Benzo[d][1,2,3]triazol-1-yl)(m-tolyl) methanone (17)
[29]
Solid: Yield: 72%; M.p.: 108e111 ꢀC; 1H NMR (300 MHz,
Solid: Yield: 69%; M.p.: 65e67 ꢀC; 1H NMR (300 MHz,
DMSO‑d6):
d
8.30 (dd, J2 ,6 /6 ,2 ¼ 2.8 Hz, J2 3/6 ,5 ¼ 8.1 Hz, 2H, H-2 ,
DMSO‑d6): d
8.31 (ovp, 2H, H-1, H-4), 7.90 (ovp, 2H, H-60, H-20), 8.85
0
0
0
0
0
0
0
0
H-60), 8.17 (d, J1,2/4,3 ¼ 9.0 Hz, 2H, H-1, H-4), 7.83 (t, J3(2,4) ¼ 7.8 Hz,
1H, H-3), 7.66 (t, J2(1,3) ¼ 8.1 Hz, 2H, H-2), 3.90 (s, 3H, OCH3), EI-MS
m/z (% rel. abund.): 253 [Mþ, 43], 225 (90), 210 (31), 182 (45), 135
(100), 107 (23), 92 (41), 77 (41); Anal. Calcd for C14H11N3O2:
(t, J3(2,4) ¼ 7.8 Hz, 1H, H-3), 7.67 (ovp, 3H, H-30, H-40, H-2), 2,40 (s,
3H, CH3), EI-MS m/z (% rel. abund.): 237 [Mþ, 7], 209 (55), 119 (100),
91 (58); Anal. Calcd for C14H11N3O: C ¼ 70.87; H ¼ 4.67; N ¼ 17.71;
O ¼ 6.74: Found: C, 70.85; H, 4.65; N, 17.69; O ¼ 6.72.

S. Hameed et al. / European Journal of Medicinal Chemistry 183 (2019) 111677
21
Table 5
Interaction detail for all derivatives against
a-glucosidase enzyme.
S. No
Interaction details
Ligands
Docking score
Receptor
Distance
E cal/mol
Residue
7
8
9
10
11
12
C 14
5-ring
CE1
O
H-
p
3.90
4.18
3.74
2.87
3.80
3.30
3.85
3.93
3.47
4.08
3.52
3.91
3.61
4.08
3.71
3.59
4.62
3.10
4.61
3.37
3.07
3.96
4.22
3.35
3.12
4.08
3.34
3.89
3.43
3.88
3.88
4.44
3.34
3.18
3.08
3.08
3.33
3.34
4.44
3.66
3.76
3.57
4.13
4.09
4.59
4.08
3.19
3.78
3.52
4.08
3.02
2.8
ꢂ0.7
ꢂ0.6
ꢂ1.0
ꢂ4.1
ꢂ0.8
ꢂ1.2
ꢂ0.6
ꢂ1.0
ꢂ1.0
ꢂ0.6
ꢂ1.7
ꢂ0.9
ꢂ0.5
ꢂ0.8
ꢂ0.6
ꢂ0.8
ꢂ0.6
ꢂ2.4
ꢂ0.8
ꢂ0.5
ꢂ0.5
ꢂ0.6
ꢂ0.7
ꢂ0.5
ꢂ0.8
ꢂ0.8
ꢂ0.8
ꢂ0.7
ꢂ0.5
ꢂ0.5
ꢂ0.5
ꢂ0.7
ꢂ0.9
ꢂ1.3
ꢂ2.3
ꢂ0.9
ꢂ0.5
ꢂ0.8
ꢂ0.7
ꢂ0.5
ꢂ1.1
ꢂ0.6
ꢂ0.6
ꢂ0.5
ꢂ0.5
ꢂ1.0
ꢂ1.2
ꢂ0.7
ꢂ0.7
ꢂ0.6
ꢂ3.9
ꢂ0.5
ꢂ3.9
ꢂ0.5
ꢂ0.8
ꢂ1.7
HIS245
PHE177
LEU437
ARG212
HIS245
GLU304
HIS245
PHE157
ASN241
HIS245
HIS279
HIS279
HIS245
THR215
HIS245
HIS245
HIS279
ARG212
HIS279
PHE300
ARG439
PHE157
THR215
ASP349
ARG212
THR215
GLU276
PRO309
GLU276
HIS245
HIS245
HIS279
GLU276
GLU276
ARG212
HIS348
GLU276
GLU276
HIS279
GLU276
HIS245
GLU276
PHE177
THR215
ARG212
HIS279
ASN241
HIS245
GLU276
HIS245
ASP408
ASP349
ASP408
ARG439
THR215
HIS279
ꢂ5.70
ꢂ5.89
ꢂ6.36
ꢂ5.87
ꢂ6.31
ꢂ5.46
5-ring
CL 19
O 17
C 15
CL 18
C 1
C 13
O 12
C 1
5-ring
5-ring
C 1
6-ring
C 6
p
-H
H-donor
H-acceptor
H-
H-donor
H-
H-
NH2
5-ring
OE2
5-ring
5-ring
ND2
5-ring
CD2
CD2
5-ring
CG2
5-ring
5-ring
CD2
NH2
CD2
6-ring
NH1
6-ring
CG2
OD2
NH2
CG2
OE1
O
OE1
5-ring
5-ring
CD2
OE1
OE1
NH2
NE2
OE1
OE1
CD2
OE1
5-ring
OE1
CE1
CG2
NH2
CD2
CD2
ND2
OE1
p
p
13
14
15
16
p
ꢂ5.42
ꢂ5.90
ꢂ5.82
ꢂ5.70
H-acceptor
H-
p
p
p
-H
-H
17
18
19
20
H-
p
ꢂ5.93
ꢂ5.93
ꢂ6.06
ꢂ5.96
p
H
H-
H-
p
p
C 14
6-ring
O 21
6-ring
N 19
N 9
C 15
6-ring
C 17
N 8
6-ring
C 18
CL 19
C 10
C 1
p
-H
H-acceptor
-H
H-
H-acceptor
H-
-H
21
ꢂ6.200
p
22
23
p
ꢂ5.73
ꢂ6.64
p
p
24
25
H-donor
H-acceptor
ꢂ5.37
p
-H
ꢂ6.095
H-donor
H-donor
H-donor
H-
H-
p-H
H-donor
H-donor
26
27
ꢂ5.98
ꢂ6.33
p
28
29
C 1
6-ring
C 18
p
ꢂ6.20
ꢂ5.99
30
31
C 10
ꢂ5.98
O 13
O 19
C 10
C 18
6-ring
C 10
H-acceptor
H-acceptor
H-donor
ꢂ6.22
H-donor
p
-H
H-donor
H-
H-donor
32
33
ꢂ6.06
ꢂ6.14
C 1
C 10
p
5-ring
6-ring
6-ring
5-ring
O 13
5-ring
CL 22
C 17
C 17
C 5
O 21
6-ring
6-ring
5-ring
p
p
p
p
-H
-H
-cation
-H
34
35
36
ꢂ5.62
ꢂ6.81
ꢂ6.41
H-acceptor
-H
p
37
H-donor
h-donor
ꢂ6.42
5-ring
5-ring
6-ring
OD2
CD
H-
i-
H-donor
p
p p
38
3.02
3.72
4.08
3.92
ꢂ6.46
p
p
p
-H
-H
-H
39
40
CG2
CD2
ꢂ6.06
ꢂ6.64
4.4.12. (1H-Benzo[d][1,2,3]triazol-1-yl)(3,4-dimethylphenyl)
methanone (18) [CAS # 333348-56-4]
4.4.13. (1H-Benzo[d][1,2,3]triazol-1-yl)(3,4,5-trimethylphenyl)
methanone (19)
Solid: Yield: 63%; M.p.: 95-94 ꢀC; 1H NMR (300 MHz, DMSO‑d6),
Solid: Yield: 81%; M.p.: 118e119 ꢀC; 1H NMR (300 MHz,
d
8.30 (dd, J1,2/4,3 ¼ 8.4 Hz, J1,3/4,2 ¼ 3.0 Hz, 2H, H-1, H-4), 7.84 (t,
DMSO‑d6):
J3(2,4) ¼ 7.5 Hz, 1H, H-3), 7.65 (t, J2(1,3) ¼ 7.8 Hz, 1H, H-2), 7.46 (s, 2H,
H-20, H-60); 13C NMR (75 MHz, DMSO‑d6):
c 166.8, 152.5, 152.4,
131.8, 130.6, 126.5, 126.1, 120.7, 114.5, 114.2, 109.3, 106., 60.2, 60.0,
56.2, 55.8; EI-MS m/z (% rel. abund.): 265 [Mþ, 29], 240 (60), 210
(17), 194 (39), 150 (100), 104 (56), 76 (33); Anal. Calcd for
d
8.29 (d, J1,2/4,3 ¼ 8.4 Hz, 2H, H-1, H-4),7.85 (t,
J3(2,4) ¼ 7.5 Hz, 1H, H-3), 7.69 (ovp, 3H, H-2, H-50, H-60), 7.41 (s, 1H,
H-20), 2.38 (s, 6H, CH3), EI-MS m/z (% rel. abund.): 251 [Mþ, 56], 223
(91), 208 (38), 133 (100), 105 (82), 77 (42); Anal. Calcd for
d
C
15H13N3O: C ¼ 71.70; H ¼ 5.21; N ¼ 16.72; O ¼ 6.37; Found:
C ¼ 71.68; H ¼ 5.20; N ¼ 16.70; O ¼ 6.36.
C16H15N3O: C ¼ 72.43; H ¼ 5.70; N ¼ 15.84; O ¼ 6.03; Found:

22
S. Hameed et al. / European Journal of Medicinal Chemistry 183 (2019) 111677
C ¼ 71.68; H ¼ 5.20; N ¼ 16.70; O ¼ 6.36.
271 [Mþ, 16], 273 (Mþþ2, 6), 140 (38), 138 (93), 132 (100), 110 (40),
104 (57),77 (86); Anal. Calcd for C14H10ClN3O: C ¼ 61.89; H ¼ 3.71;
Cl ¼ 13.05; N ¼ 15.47; O ¼ 5.89; Found: C ¼ 61.88; H ¼ 3.69;
Cl ¼ 13.03; N ¼ 15.44; O ¼ 5.86.
4.4.14. (1H-Benzo[d][1,2,3]triazol-1-yl)(4-nitrophenyl)methanone
(20) [30]
Solid: Yield: 74%; M.p.: 188e193 ꢀC; 01H NMR (300 MHz,
0
0
0
0
0
DMSO‑d6):
d
8.46 (d, J2 3 /6 ,5 ¼ 8.7 Hz, 2H, H-2 , H-6 ), 8.48 (ovp, 4H,
4.4.20. 2-(1H-Benzo[d][1,2,3]triazol-1-yl)-1-(3,4-dichlorophenyl)
ethan-1-one (26) [CAS #1456055-61-0]
H-30, H-50, H-1, H-4), 7.88 (t, J3(2,4) ¼ 7.5 Hz, 1H, H-3), 7.70 (t,
J2(1,3) ¼ 7.8 Hz,1H, H-2), EI-MS m/z (% rel. abund.): 268 [Mþ, 29], 240
(60), 210 (17), 194 (39), 150 (100), 104 (56), 76 (33); Anal. Calcd for
Solid: Yield: 76%; M.p.: 179e181 ꢀC; 1H NMR (300 MHz,
0
0
0
0
0
DMSO‑d6),
30,20
d
8.37 (d, J6 ,2 ¼ 1.8 Hz, 1H, H-6 ), 8.09 (dd, J2 ,3 /
0
0
0
0
C
13H8N4O3: C ¼ 58.21; H ¼ 3.01; N ¼ 20.89; O ¼ 17.89; Found:
¼ 8.4 Hz, J2 ,6 ¼ 3.6 Hz, 2H, H-2 , H-3 ), 7.93 (d, J 4,3 ¼ 8.4 Hz, 1H,
C ¼ 58.18; H ¼ 3.00; N ¼ 20.84; O ¼ 17.86.
H-4), 7.80 (d, J1,2 ¼ 8.4 Hz, 1H, H-1), 7.55 (t, J3(2,4) ¼ 7.5 Hz, 1H, H-3),
7.44 (t, J2(1,3) ¼ 7.8 Hz, 1H, H-2), 6.59 (s, 2H, CH2), EI-MS m/z (% rel.
abund.): 305 [Mþ, 14], 307 (Mþþ2, 9), 248 (24), 144 (54), 132 (100),
104 (70), 77 (80); Anal. Calcd for C14H9Cl2N3O: C ¼ 54.93; H ¼ 2.96;
Cl ¼ 23.16; N ¼ 13.73; O ¼ 5.23; Found: C ¼ 54.91; H ¼ 2.94;
Cl ¼ 23.14; N ¼ 13.71; O ¼ 5.21.
4.4.15. (1H-Benzo[d][1,2,3] triazol-1-yl)(3-methyl-4-nitrophenyl)
methanone (21) [CAS # 328555-26-6]
Solid: Yield: 67%; M.p.: 109e112 ꢀC; 1H NMR (300 MHz,
DMSO‑d6):
d
8.35 (t, J1,2/4,3 ¼ 8.4 Hz, 2H, H-1, H-4),8.20 (ovp, 3H, H-
20, H-50, H-60), 7.88 (t, J3(2,4) ¼ 7.2 Hz, 1H, H-3), 7.70 (t, J2(1,3) ¼ 7.8 Hz,
1H, H-2), 2.60 (s, 3H, CH3), EI-MS m/z (% rel. abund.): 282 [Mþ, 24],
254 (19), 237 (22), 164 (100), 118 (38), 106 (26) 89 (24); Anal. Calcd
for C13H8N4O3: C ¼ 59.57; H ¼ 3.57; N ¼ 19.85; O ¼ 17.00; Found:
C ¼ 59.56; H ¼ 3.55; N ¼ 19.83; O ¼ 16.98.
4.4.21. 2-(1H-Benzo[d] [1e3]triazol-1-yl)-1-(2,3-dichlorophenyl)
ethan-1-one (27)
Solid: Yield: 60%; M.p.: 144e146 ꢀC; 1H NMR (300 MHz,
DMSO‑d6),
d
8.16 (dd, J1,2/4,3 ¼ 8.4 Hz, 2H, H-1, H-4), 7.84 (ovp, 2H, H-
50, H-60), 7.71 (d, J4’,6 ¼ 1.8 Hz, J4’,5 ¼ 8.4 Hz, 1H, H-4 ), 7.58 (t,
0
0
0
4.4.16. (3-Amino-4-chlorophenyl)(1H-benzo[d][1,2,3] triazol-1-yl)
methanone (22)
J3(2,4) ¼ 7.8 Hz, 1H, H-3), 7.45 (t, J2(1,3) ¼ 7.5 Hz, 1H, H-2), 6.44 (s, 2H,
CH2); 13C NMR (75 MHz, DMSO‑d6):
dc 193.1, 145.0, 137.4, 133.7,
Solid: Yield: 58%; M.p.: 133e144 ꢀC; 1H NMR (300 MHz,
133.4, 132.1, 131.6, 130.5, 127.6, 127.5, 123.9,119.1, 110.8, 56.02; EI-MS
m/z (% rel. abund.): 305 [Mþ, 3], 307 (Mþþ2, 2),132 (100), 104 (35),
77 (63), HREI-MS Calcd for C14H9Cl2N3O m/z 305.0117, Found:
DMSO‑d6):
d
8.30 (d, J1,2/4,3 ¼ 9.0 Hz, 2H, H-1, H-4), 7.84 (t,
J3(2,4) ¼ 7.8 Hz, 1H, H-3), 7.86 (t, J2(1,3) ¼ 8.4 Hz, 1H, H-2), 7.54 (d,
0
¼ 8.1 Hz, 1H, H-30), 7.28 (dd,
305.0128; Anal. Calcd for
C
14H9Cl2N3O: C ¼ 54.93; H ¼ 2.96;
0
0
30,20
0
J5 ,2 ¼ 1.8 Hz, 1H, H-5 ), 7.46 (d, J
J2 ,5 ¼1.8 Hz, J2 ,3 ¼ 6.3 Hz, 1H, H-2 ), 5.80 (s, 2H, NH2); 13C NMR
Cl ¼ 23.16; N ¼ 13.73; O ¼ 5.23; Found: C ¼ 54.90; H ¼ 2.93;
0
0
0
0
(100 MHz, DMSO‑d6):dc 166.0, 145.1, 144.7, 131.7, 130.6, 130.6, 129.0,
Cl ¼ 23.12; N ¼ 13.69; O ¼ 5.20.
126.6, 122.2, 119.9, 119.4, 117.5, 114.4; EI-MS m/z (% rel. abund.): 272
[Mþ, 83], 274 (Mþþ2, 25), 244 (34), 156 (51), 154 (100), 126 (43), 90
(39); Anal. Calcd for C13H9ClN4O: C ¼ 57.26; H ¼ 3.33; Cl ¼ 13.00;
N ¼ 20.55; O ¼ 5.87; Found: C ¼ 57.23; H ¼ 3.31; Cl ¼ 12.98;
N ¼ 20.53; O ¼ 5.85.
4.4.22. 2-(1H-Benzo[d][1,2,3]triazol-1-yl)-1-(3-bromophenyl)
ethan-1-one (28) [CAS # 1455104-78-5]
Solid: Yield: 75%; M.p.: 126e128 ꢀC; 1H NMR (300 MHz,
0
DMSO‑d6):
d
8.29 (s, 1H, H-20), 8.11 (t, J6 ,5 /4 ,5 ¼ 7.5 Hz, 2H, H-6 , H-
0
0
0
0
40), 7.97 (d, J4,3 ¼ 7.8 Hz, 1H, H-4), J
¼ 8.1 Hz, 1H, H-1),7.62(t, J3
1,4
0
0
4.4.17. (1H-Benzo[d][1,2,3]triazol-1-yl)(4-butoxyphenyl)
methanone (23) [CAS # 574711-93-6]
¼ 7.8 Hz, 1H, H-3), 7.55 (t, J2(1,3) ¼ 7.8 Hz, 1H, H-2), 7.44 (t, J5 ,4 /
(2,4)
50,60
¼ 7.8 Hz, 1H, H-50), 6.59 (s, 2H, CH2), EI-MS m/z (% rel. abund.):
Solid: Yield: 80%; M.p.: 126e137 ꢀC; 1H 0NMR 0 (300 MHz,
315 [Mþ, 7], 317 (Mþþ2, 7),183 (3),132 (100),104 (33), 77 (47); Anal.
Calcd for C14H10BrN3O: C ¼ 53.19; H ¼ 3.19; Br ¼ 25.27; N ¼ 13.29;
O ¼ 5.06; Found: C ¼ 53.17; H ¼ 3.17; Br ¼ 25.25; N ¼ 13.27;
O ¼ 5.04.
0
0
0
0
DMSO‑d6),
d
8.24 (d J2 3 /6 ,5 ¼ 7.8 Hz, 2H, H-2 , H-6 0), 8.18 (d,
0
0
J1,2 ¼ 8.1 Hz, 1H, H-1), 8.16 (d, J3 ,2 ¼ 8.7 Hz, 1H, H-3 ), 7.82 (t,
J3(2,4) ¼ 7.2 Hz, 1H, H-3), 7.65 (t, J2(1,3) ¼ 7.8 Hz, 1H, H-2), 7.18 (d,
0
0
0
J5 ,6 ¼ 8.7 Hz, 1H, H-5 ), 7.13 (d, J 4,3 ¼ 9.0 Hz, 1H, H-4), 4.14 (ovp, 2H,
CH2), 1.79 (ovp, 2H, CH2), 1.51 (ovp, 2H, CH2), 0.96 (ovp, 3H, CH3), EI-
MS m/z (% rel. abund.): 295 [Mþ, 22], 211 (42), 177 (100), 121 (88);
4.4.23. 2-(1H-Benzo[d][1,2,3]triazol-1-yl)-1-(4-bromophenyl)
ethan-1-one (29) [30]
Anal. Calcd for
O ¼ 10.83; Found: C ¼ 69.12; H ¼ 5.77; N ¼ 14.21; O ¼ 10.81.
C
17H17N3O2: C ¼ 69.14; H ¼ 5.80; N ¼ 14.23;
Solid: Yield: 65%; M.p.: 160e196 ꢀC; 1H NMR (300 MHz,
0
0
DMSO‑d6):
60,50
d
8.09 (d, J4,3 ¼ 6.9 Hz, 1H, H-4), 8.06 (dd, J2 ,3 /
0
0
0
0
0
0
0
¼ 6.9 Hz, 2H, H-2 , H-6 ), 7.84 (d, J3 ,2 /5 ,6 ¼ 8.4 Hz, 2H, H-3 , H-
4.4.18. (1H-Benzo[d][1,2,3]triazol-1-yl)(phenyl)methanone (24)
[28]
50), 7.80 (d, J1,2 ¼ 8.4 Hz, 1H, H-1),7.55 (t, J3(2,4) ¼ 7.5 Hz, 1H, H-
3),7.44 (t, J2(1,3) ¼ 7.8 Hz, 1H, H-2), 6.57 (s, 2H, CH2), EI-MS m/z (% rel.
abund.): 315 [Mþ, 9], 317 (Mþ þ2, 9), 132 (100), 104 (50), 77 (81);
Solid; Yield: 63%; M.p.: 102e104 ꢀC; 1H NMR (300 MHz,
0
0
0
DMSO‑d6),
d
8.34 (ovp, 2H, H-1, H-4), 8.12 (d, J2 ,3/6 ,5 ¼ 7.5 Hz, 2H,
Anal. Calcd for
C
14H10BrN3O: C ¼ 53.19; H ¼ 3.19; Br ¼ 25.27;
H-20, H-60), 7.86 (t, J3(2,4) ¼ 7.8 Hz, 1H, H-3), 7.79 (t, J2(1,3) ¼ 7.5 Hz,
1H, H-2), 7.68 (ovp, 3H, H-30, H-40, H-50), EI-MS m/z (% rel. abund.):
223 [Mþ, 24], 195 (100), 167 (44), 105 (100), 77 (89), 51 (38); Anal.
Calcd for C13H9N3O: C ¼ 69.95; H ¼ 4.06; N ¼ 18.82; O ¼ 7.17;
Found: C ¼ 69.92; H ¼ 4.03; N ¼ 18.80; O ¼ 7.15.
N ¼ 13.29; O ¼ 5.06; Found: C ¼ 53.17; H ¼ 3.17; Br ¼ 25.25;
N ¼ 13.27; O ¼ 5.04.
4.4.24. 2-(1H-Benzo[d][1,2,3]triazol-1-yl)-1-(2-hydroxyphenyl)
ethan-1-one (30)
Solid: Yield: 60%; M.p.: 160e165 ꢀC; 1H NMR (300 MHz,
4.4.19. 2-(1H-Benzo[d][1,2,3]triazol-1-yl)-1-(4-chlorophenyl)
ethan-1-one (25) [31]
DMSO‑d6):
d
11.21 (s, 1H, OH), 8.08 (d, J ¼ 8.4 Hz, 1H, H-4), 7.88 (dd,
J6’,5 ¼ 6.6 Hz, J
¼1.5 Hz, H-60), 7.81 (d, J
¼ 8.4 Hz, 1H, H-1),
0
60,40
1,2
Solid: Yield: 55%; M.p.: 150e152 ꢀC; 1H 0 NMR (300 MHz,
7.59 (ovp, 2H, H-50, H-3), 7.43 (t, J2(1,3) ¼ 7.8 Hz, 1H, H-2), 7.10 (d,
DMSO‑d6),
¼ 8.7 Hz, 2H, H-2 , H-60), 8.09 (d, J
J3 ,4 ¼ 8.4 Hz, 1H, H-3 ), 7.02 (t, J4 (3 ,5 ) ¼ 7.4 Hz, 1H, H-40), 7.02 (t,
0
20,30/60,50
d 8.15 (d, J
0
0
0
0
0
J3 ,5 ¼ 7.5 Hz, 1H, H-4 ), 6.39 (s, 2H, CH2); 13C NMR (75 MHz,
0
0
0
0
¼ 8.1 Hz, 1H, H-4), 7.81 (d, J1,2 ¼ 8.4 Hz, 1H, H-1), 7.73 (d, J3 ,2/
4,3
¼ 8.4 Hz, 2H, H-30, H-50), 7.55 (t, J3(2,4) ¼ 7.8 Hz, 1H, H-3), 7.44 (t,
DMSO):dc 193.9, 159.6, 145.0, 136.0, 133.9, 130.2, 127.2, 123.7, 120.6,
50,60
J2(1,3) ¼ 7.8 Hz, 1H, H-2), 6.57 (s, 2H, CH2), EI-MS m/z (% rel. abund.):
119.4, 118.9,117.6, 111.0, 56.4; EI-MS m/z (% rel. abund.): 253 [Mþ,

S. Hameed et al. / European Journal of Medicinal Chemistry 183 (2019) 111677
23
0
0
0
0
0
0
44], 225 (26),132 (38),121 (100),104 (36), 93 (23), 77 (71), HREI-MS
m/z Calcd for C14H11N3O2 253.0851 Found 253.0850; Anal. Calcd for
2), 7.72 (d, J3 ,2 /5 ,6 ¼ 8.4 Hz, 2H, H-3 , H-5 ), 7.54 (s, 1H, H-1), 6.47 (s,
2H, CH2), 2.36 (s, 3H, H-200, CH3), 2.36 (s, 3H, H-100, CH3), EI-MS m/z
(% rel. abund.): 299 [Mþ, 6], 301 (Mþþ2, 2), 242 (13), 160 (100), 139
(46), 132 (96), 105 (41); Anal. Calcd for C16H14ClN3O: C ¼ 64.11;
H ¼ 4.71; Cl ¼ 11.83; N ¼ 14.04; O ¼ 5.34; Found: C ¼ 64.09;
H ¼ 4.69; Cl ¼ 11.81; N ¼ 14.02; O ¼ 5.32.
C
14H11N3O2: C ¼ 66.40; H ¼ 4.38; N ¼ 16.59; O ¼ 12.63; Found:
C ¼ 66.36; H ¼ 4.36; N ¼ 16.55; O ¼ 12.60.
4.4.25. 2-(1H-Benzo[d][1,2,3]triazol-1-yl)-1-(3-nitrophenyl)ethan-
1-one (31) [30]
Solid: Yield: 71%; M.p.: 173e177 ꢀC; 1H NMR (300 MHz,
4.4.31. 1-(3,4-Dichlorophenyl)-2-(5,6-dimethyl-1H-benzo[d] [1e3]
triazol-1-yl)ethan-1-one (37)
0
0
0
0
0
DMSO‑d6):
d
8.84 (s,1H, H-20), 7.59 (dd, J4 ,5 /6 ,5 ¼ 7.8 Hz, 2H, H-4 ,
H-60), 8.10 (d, J3(2,4) ¼ 8.4 Hz, 1H, H-1), 7.96 (t, J5 ,4 /5 ,6 ¼ 8.1 Hz, 1H,
H-50), 7.84 (d, J1,2 ¼ 8.1 Hz, 1H, H-1), 7.56 (t, J3(2,4) ¼ 7.8 Hz, 1H, H-3),
7.45 (t, J2(1,3) ¼ 7.8 Hz, 1H, 2), 6.70 (s, 2H, CH2), EI-MS m/z (% rel.
abund.): 282 [Mþ, 6], 150 (24), 132 (100), 104 (37), 77 (53); Anal.
Calcd for C14H10N4O3: C ¼ 59.57; H ¼ 3.57; N ¼ 19.85; O ¼ 17.00;
Found: C ¼ 59.55; H ¼ 3.56; N ¼ 19.83; O ¼ 16.98.
0
0
0
0
Solid: Yield: 70%; M.p.: 190e196 ꢀC; 1H NMR (300 MHz,
0
0
0
0
DMSO‑d6),
d
8.360(d, J6ʹ,2 ¼ 1.8 Hz, 1H, H-6 ), 8.06 (dd, J2 ,3 ¼ 1.8 Hz,
0
0
0
0
0
J2 ,6 ¼ 6.6 Hz, H-2 ), 7.93 (d, J2 ,3 ¼ 8.4 Hz,1H, H-3 ), 7.81 (s,1H, H-2),
7.54 (s, 1H, H-1), 6.49 (s, 2H, CH2), 2.36 (s, 3H, H-200, CH3), 2.34 (s,
3H, H-100, CH3); 13C NMR (75 MHz, DMSO):
dc 190.8, 144.3, 137.3,
136.9, 134.4, 132.8, 131.9, 131.2, 130.8, 128.2, 118.1, 109.9, 54.1, 20.3,
19.8; EI-MS m/z (% rel. abund.): 333 [Mþ, 4], 335 (Mþ þ2, 2), 305
(23), 276 (28), 173 (66), 160 (81), 132 (100), 105 (68), 77 (26), HREI-
MS m/z: Calcd for C16H13Cl2N3O 333.0436, Found: 333.0445; Anal.
Calcd for C16H13Cl2N3O: C ¼ 53.50; H ¼ 4.92; Cl ¼ 22.21; N ¼ 11.57;
O ¼ 4.79; Found: C ¼ 53.30; H ¼ 4.88; Cl ¼ 22.16; N ¼ 11.51;
O ¼ 4.73.
4.4.26. 2-(1H-Benzo[d][1,2,3]triazol-1-yl)-1-(4-methoxyphenyl)
ethan-1-one (32) [30]
Solid: Yield: 60%; M.p.: 135e136 ꢀC; 1H NMR (300 MHz,
DMSO‑d6):
d
8.11 (ovp, 3H, H-20, H-60, H-4), 7.77 (d, J4,3 ¼ 8.1 Hz, 1H,
H-4), 7.54 (t, J3(2,4) ¼ 8.1 Hz, 1H, H-03),7.43 (t, J2(1,3) ¼ 7.5 Hz, 1H, H-2),
0
0
0
0
0
7.16 (d, J3 ,2 /5 ,6 ¼ 8.7 Hz, 2H, H-3 , H-5 ), 6.49 (s, 2H, CH2), 3.88(s,
3H, OCH3), EI-MS m/z (% rel. abund.): 267 [Mþ, 25], 135 (100), 107
(32), 92 (28), 77 (80); Anal. Calcd for C15H13N3O2: C ¼ 67.40;
H ¼ 4.90; N ¼ 15.72; O ¼ 11.97; Found: C ¼ 67.38; H ¼ 4.88;
N ¼ 15.70; O ¼ 11.95.
4.4.32. 2-(5,6-Dimethyl-1H-benzo[d][1,2,3]triazol-1-yl)-1-(2-
hydroxyphenyl)ethan-1-one (38)
Solid: Yield: 72%; M.p.: 177e179 ꢀ0 C; 1H NMR (300 MHz,
0
0
DMSO‑d6), 7.89 (d, J6 ,5 ¼ 6.9 Hz, 1H, H-6 ), 7.80 (s, 1H, H-2), 7.58(t,
J5 ,4 /5 ,6 ¼ 9.6 Hz, 1H, 50-H), 7.53 (br.s, 1H, H-1), 7.08 (d,
J
0
0
0
0
4.4.27. 2-(1H-Benzo[d][1,2,3]triazol-1-yl)-1-(p-tolyl)ethan-1-one
(33) [31]
0
0
30,40
0
0
0
0
¼ 8.1 Hz, 1H, H-3 ), 7.02 (t, J4 ,3 /4 ,5 ¼ 7.5 Hz, 1H, H-4 ), 6.30 (s,
2H, CH2), 2.36 (s, 3H, H-200, CH3), 2.36 (s, 3H, H-100, CH3); 13C NMR
Solid: Yield: 70%; M.p.: 134e146 ꢀC; 1H NMR (300 MHz,
(75 MHz, DMSO): c 194.2, 159.6, 144.3, 137.1, 136.0, 133.1, 132.9,
d
0
0
0
0
DMSO‑d6):
d
8.13 (d J1,3 ¼ 9.0 Hz, 1H, H-1), 8.04 (d, J 2 ,3 /6 ,5 ¼ 6.0 Hz,
2H, H-20, H-60), 7.79(d, J 4,3 ¼ 9.0 Hz,1H, H-4), 7.56 (t, J3 (2,4) ¼ 9.0 Hz,
130.2, 120.4, 119.4, 117.9,117.5, 110.0, 56.0, 20.2, 19.8; EI-MS m/z (%
rel.abund.): 281 [Mþ, 54], 253 (21), 160 (55), 132 (100), 121 (77),105
(33); HREI-MS calcd for C16H15N3O2 m/z 281.1164 Found: 281.1161;
0
0
0
0
0
0
1H, H-3), 7.45 (t, J 3 ,2 /5 ,6 ¼ 9 Hz, 2H, H-3 , H-5 ), 7.45 (ovp, 1H, H-2),
6.53 (s, 2H, CH2), 2.43 (s, 3H, CH3), EI-MS m/z (% rel. abund.): 251
[Mþ, 14], 132 (29), 119 (100), 104 (26), 91 (70), 77 (63); Anal. Calcd
for C15H13N3O: C ¼ 71.70; H ¼ 5.21; N ¼ 16.72; O ¼ 6.37; Found:
C ¼ 71.68; H ¼ 5.19; N ¼ 16.70; O ¼ 6.35.
Anal. Calcd for
C
16H15N3O2: C ¼ 65.31; H ¼ 6.37; N ¼ 13.94;
O ¼ 10.37; Found: C ¼ 65.25; H ¼ 6.33; N ¼ 13.89; O ¼ 10.35.
4.4.33. 2-(5,6-Dimethyl-1H-benzo[d][1,2,3]triazol-1-yl)-1-
phenylethan-1-one (39) [CAS #1907374-75-7]
4.4.28. 2-(5,6-Dimethyl-1H-benzo[d][1,2,3]triazol-1-yl)-1-(4-
methoxyphenyl)ethan-1-one (34) [CAS # 127876-36-2]
Solid: Yield: 87%; M.p.: 111e114 ꢀC; 1H NMR (300 MHz,
Solid: Yield: 59%; M.p.: 149e151 ꢀC; 1H NMR (300 MHz,
0
0
0
0
0
0
DMSO‑d6),
d
8.13 (d, J2 ,3 /6 ,5 ¼ 7.5 Hz, 2H, H-2 , H-4 ), 7.81 (s, 1H, H-
DMSO‑d6):
d
8.14 (d, J2,3/6,5 ¼ 7.5 Hz, 2H, H-20, H-60), 8.09 (d,
0
0
0
0
0
(2030)/50 (6 ,4)
2), 7.77 (t, J4
¼ 7.5 Hz, 1H, H-40), 7.65 (t, J3
¼ 7.5 Hz,
(3 ,5 )
J1,2 ¼ 8.4 Hz, 1H, H-1), 7.81 (ovp, 2H, H-40, H-4),7.65 (t, J3 (2 ,4 )/5
0
0
0
0
2H, H-30, H-50), 7.54 (s, 1H, H-1), 6.47 (s, 2H, CH2), EI-MS m/z (%
rel.abund.): 265 [Mþ, 4], 208 (18), 160 (54), 132 (100), 105 (73), 51
(53); Anal. Calcd for C16H15N3O: C ¼ 72.43; H ¼ 5.70; N ¼ 15.84;
O ¼ 6.03; Found: C ¼ 72.41; H ¼ 5.68; N ¼ 15.82; O ¼ 6.01.
¼ 7.5 Hz, 2H, H-30, H-50), 7.55 (t, J3 (2,4) ¼ 7.8 Hz, H-3), 7.44 (t,
0
0
(4 ,6 )
J2(1,2) ¼ 7.8 Hz, H-2), 6.57 (s, 2H, CH2), EI-MS m/z (% rel. abund.): 237,
[Mþ, 23], 209 (19), 180 (25), 132 (42), 105 (5), 77 (4); Anal. Calcd for
C
14H11N3O: C ¼ 70.87; H ¼ 4.67; N ¼ 17.71; O ¼ 6.74; Found:
C ¼ 70.85; H ¼ 4.64; N ¼ 17.69; O ¼ 6.72.
4.4.34. 2-(5,6-Dimethyl-1H-benzo[d][1,2,3]triazol-1-yl)-1-(4-
methoxyphenyl) ethan-1-one (40)ssss
4.4.29. 1-([1,10-Biphenyl]-4-yl)-2-(1H-benzo[d][1,2,3]triazol-1-yl)
ethan-1-one (35) [31]
Solid: Yield: 67%; M.p.: 139e142 ꢀC; 1H NMR (300 MHz,
0
0
0
0
DMSO‑d6),
d
8.13 (d, J3 ,5 ¼ 8.7 Hz, 2H, H-2 , H-6 ), 7.74 (s, 1H, H-2),
Solid: Yield: 73%; M.p.: 149e155 ꢀC; 1H 0 NMR0 (300 MHz,
0
0
0
0
7.37 (s, 1H, H-1), 7.11 (d, J2 ,6 ¼ 9.0 Hz, 2H, H-3 , H-5 ), 6.26 (s, 2H,
0
0
0
0
DMSO‑d6):
d
8.23 (d, J2 ,3 /6 ,5 ¼ 8.4 Hz, 2H, H-2 , H-60), 8.10 (d, J
CH2), 3.91 (s, 3H, OCH3), 2.43 (s, 3H, H-100, CH3),2.41 (s, 3H, H-200,
0
0
0
0
0
¼ 8.1 Hz, 1H, H-4), 7.95 (d, J3 ,4 /5 ,6 ¼ 8.4 Hz, 2H, H-3 , H-5 ), 7.82
4,3
CH3); 13C NMR (75 MHz, DMSO):
dc 190.5, 163.9, 144.3, 137.1, 133.1,
(ovp ¼ 3H, H-200, H-600, H-1), 7.56 (J3
¼ 8.1 Hz,
00
00 00
(200,400)/500 (600,400)/400 (3 ,5 )
133.0,130.7,127.0,117.9,114.1,109.9, 55.6, 53.5, 20.9,19.8; EI-MS m/z
(% rel. abund.): 295 (Mþ, 24), 267 (9), 239 (14), 160 (24), 135 (100),
105 (16); HREI-MS Calcd for C17H17N3O2 m/z 295.1321 Found:
295.1306; Anal. Calcd for: C ¼ 59.10; H ¼ 4.76; N ¼ 15.20; O ¼ 12.83;
Found: C ¼ 59.08; H ¼ 4.75; N ¼ 15.17; O ¼ 12.81.
3H, H-300, H-500, H-400), 7.45 (t, J2(1,3)/3(2,4) ¼ 7.8 Hz, 2H, H-2, H-3),
6.60 (s, 2H, CH2), EI-MS m/z (% rel. abund.): 313 [Mþ, 5], 181 (100),
152 (28), 77 (17); Anal. Calcd for C20H15N3O: C ¼ 76.66; H ¼ 4.83;
N ¼ 13.41; O ¼ 5.11; Found: C ¼ 76.64; H ¼ 4.80; N ¼ 13.39;
O ¼ 5.10.
4.4.30. 1-(4-Chlorophenyl)-2-(5,6-dimethyl-1H-benzo[d][1,2,3]
triazol-1-yl)ethan-1-one (36) [CAS #1902036-34-3]
Acknowledgements
Solid: Yield: 70%; M.p.: 177e191 ꢀC; 01H NMR (300 MHz,
The authors are thankful to the Pakistan Academy of Sciences for
providing financial support to Project No. (5-9/PAS/440).
0
0
0
0
0
DMSO‑d6)
d
8.14 (d, J2 ,3 /6 ,5 ¼ 8.4 Hz, 2H, H-2 H-6 ), 7.80 (s, 1H, H-

24
S. Hameed et al. / European Journal of Medicinal Chemistry 183 (2019) 111677
molecular docking study, Eur. J. Med. Chem. 141 (2017) 530e537.
[17] M. Taha, N.H. Ismail, S. Imran, M.H. Mohamad, A. Wadood, F. Rahim,
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S. Vijayabalan, Biology-oriented drug synthesis (BIODS) of 2-(2-methyl-5-
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