Biologically Active Heterocyclic Hybrids Based on Quinazolinone, Benzofuran and Imidazolium Moieties: Synthesis, Characterization, Cytotoxic and Antibacterial Evaluation

Article abstract of DOI:10.1002/cbdv.201600411

Cytotoxic and antimicrobial agents structurally based on quinazolinone, benzofuran and imidazole pharmacophores, have been designed and synthesized. Spectral (IR, ¹H-NMR) and elemental analysis data established the structures of these novel 3-[1-(1-benzofuran-2-yl)-2-(4-oxoquinazolin-3(4H)-yl)ethyl]-1-methyl-1H-imidazol-3-ium chloride hybrid derivatives. All the synthesized compounds were evaluated for in?vitro cytotoxicity and antimicrobial activities. Cytotoxic evaluation using MTT assay revealed that compounds 12c, 12g and 12i exhibited significant cytotoxicity with IC₅₀ values 1, 1, and 0.57?μm on this cell line, respectively. Biological activity of the synthesized compounds as antibacterial agent were also evaluated against three Gram-negative (Escherichia coli, Pseudomonas aeruginosa and Salmonella typhi), three Gram-positive (Staphylococcus aureus, Bacillus subtilis and Listeria monocitogenes) and one yeast-like fungi (Candida albicans) strains. All compounds 12a?–?12i showed slightly higher activity against Gram-positive bacteria than the Gram-negative one. Among the nine new compounds screened, 3-[1-(5-bromo-1-benzofuran-2-yl)-2-(6-chloro-4-oxoquinazolin-3(4H)-yl)ethyl]-1-methyl-1H-imidazol-3-ium chloride (12e) has pronounced higher antimicrobial activity against all tested strains. These results demonstrated potential importance of molecular hybridization in the development of new lead molecules with major cytotoxicity and antimicrobial activity.

Full text of DOI:10.1002/cbdv.201600411

Received Date: 04/11/2016
Revised Date: 15/12/2016
Accepted Date: 19/12/2016
Article Type: Full Paper
Biologically Active Heterocyclic Hybrids Based on Quinazolinone,
Benzofuran and Imidazolium Moieties: Synthesis, Characterization,
Cytotoxic and Antibacterial Evaluation
by Parvin Asadia), Ghadamali Khodarahmi*,a), Ali Jahanian-Najafabadib),
Lotfollah Saghaiea), Farshid Hassanzadeha)
a) Department of Medicinal Chemistry, School of Pharmacy and Pharmaceutical Sciences,
Isfahan University of Medical Sciences, Isfahan, 81746-73461, I.R.Iran
E-mail: khodarahmi@pharm.mui.ac.ir (G.A. Khodarahmi)
b) Department of Pharmaceutical Biotechnology, School of Pharmacy and Pharmaceutical
Sciences, Isfahan University of Medical Sciences, Isfahan, Iran
ABSTRACT
Cytotoxic and antimicrobial agents structurally based on quinazolinone, benzofuran and
imidazole pharmacophores, have been designed and synthesized. Spectral (IR, 1H NMR) and
elemental analysis data established the structures of these novel 1-[[(1-(benzofuran-2-yl)-2-
This article has been accepted for publication and undergone full peer review but has not
been through the copyediting, typesetting, pagination and proofreading process, which may
lead to differences between this version and the Version of Record. Please cite this article as
doi: 10.1002/cbdv.201600411
This article is protected by copyright. All rights reserved.

(quinazolin-4(3H)-one-3-yl)]ethyl-1-yl]-3- methyl imidazol-1-ium chloride hybrid
derivatives. All the synthesized compounds were evaluated for in vitro cytotoxicity and
antimicrobial activities. Cytotoxic evaluation using MTT assay revealed that compounds 12c,
12g and 12i exhibited significant cytotoxicity with IC50 values 1, 1, 0.57 µM on this cell line,
respectively. Biological activity of the synthesized compounds as antibacterial agent were
also evaluated against three Gram-negative (Escherichia coli, Pseudomonas aeruginosa and
Salmonella typhi), three Gram-positive (Staphylococcus aureus, Bacillus subtilis and Listeria
monocitogenes) and one yeast-like fungi (Candida albicans) strains. All compounds (12a-i)
showed slightly higher activity against Gram-positive bacteria than the Gram-negative one.
Among the nine new compounds screened, 1-[[(1-(5-bromo benzofuran-2-yl) -2-(6-chloro
quinazolin-4(3H)-one-3-yl)] ethyl-1-yl]-3- methyl imidazol-1-ium chloride (12e) has
pronounced higher antimicrobial activity against all tested strains. These results demonstrated
potential importance of molecular hybridization in the development of new lead molecules
with major cytotoxicity and antimicrobial activity.
Keywords: Quinazolinone, Benzofuran, Imidazolium salt, antibacterial, cytotoxic
Introduction
Indiscriminate prescribing of antibiotics and non-compliance of its treatment regimes has
promoted the rapid rise in bacterial resistance for many classes of these compounds. So, new
class of synthetic or natural antibacterial agents, having a new mechanism of action which
involves in early inhibition of bacterial protein synthesis, is necessary [1-3]. On the other
hand, increasing the number of cancer cases and severe side-effects of chemotherapeutic
agents reduce the clinical efficacy of the large variety of antitumor agents. Thus, the need for
discovery and develop alternative or synergistic anticancer drugs with minimal side-effects is
This article is protected by copyright. All rights reserved.

still the key focus of several pharmaceutical companies. Identification of cytotoxic
compounds is a one important strategy to develop of anticancer therapeutics [4-5].
Besides the exploitation of new targets, hybridization approach is an emerging
strategy within drug discovery which is based on the fusion of two drugs, two active
compounds and/or pharmacophoric units of known bioactive molecules to produce a new
compound with improved affinity and efficacy, compared to the parent drugs [6-7]. This
strategy is believed to be analogous to conventional combination therapy, with the exception
that the two drugs are covalently linked and available as a single entity [8]. The selection of
the drugs or pharmacophores is usually based on their observed pharmacological activities to
enable the identification of highly active novel chemical entities and it is expected that the
hybrid molecules might exhibit different and/or dual modes of action, modified selectivity
profile and reduced undesired side effects [9-13]. As an example the hybridization approach
has already been applied in developing novel antibacterial and antimalarial agents to
overcome drug resistance [14-17].
Heterocyclic structures are the basic elements of many pharmaceuticals products.
Quinazolinone skeleton has been considered as a magic heterocyclic moiety possessing many
types of pharmacological activities. Various novel classes of structurally different
quinazolinones have been designed and synthesized depicting potential interventions such as,
antiviral, anticonvulsant, CNS depressant, anti-inflammatory, antihistaminic, anticancer and
so on [18, 19]. The quinazolinones have emerged as anti-microbial agents with potential
activity against a wide spectrum of significant bacterial pathogens with resultant broad
clinical. Diverse examples of quinazolinones were also reported which exerted cytotoxic
effects against different cancerous cell line [20-23].
This article is protected by copyright. All rights reserved.

So far, the compounds containing benzofuran have been synthesized intensively with
various reasons, the major of which is their biological activities. Natural and synthesized
benzofurans exhibit a variety of valuable pharmacological properties such as anti-
inflammatory, anti-microbial, antifungal, anti-hyperglycemic, analgesic, ant parasitic, and
antitumor activities [24-26].
Imidazole as privileged structures is endowed with various biological activities [27-
29]. The valuable therapeutic properties of the imidazole related drugs have encouraged the
medicinal chemists to synthesize a large number of chemotherapeutic agents such as
ketoconazole, miconazole, tioconazole, clotrimazole and sulconazole etc. Biological activities
of imidazolium salts have also been reported [27]. Recently novel hybrid compounds based
on benzofurans and imidazols moieties were synthesized which showed potent cytotoxic
activity against different human cancer cell lines [30, 31].
Considering the biological activities of imidazole and benzofurane derivatives, as well
as quinazolinone derivatives, we were interested in the synthesis of new hybrid compounds
bearing these three pharmacophoric elements (quinazolinone, benzofuran and imidazole) in a
single chemical framework. The objective of forming these hybrids is an attempt to reach
active antibacterial and/or cytotoxic agents with potentiated activity. For this purpose, these
pharmacophores were put together in such a way to arrange them in a symmetrical shape, and
subsequently routine synthetic procedure was used for the preparation of these novel hybrid
compounds (Scheme 1). As a starting point for the study, salicylaldehyde derivatives were
used for preparation of benzofuran nucleolus and antheranilic acid derivatives were utilized
as initial material for the synthesis of quinazolinone moieties. Subsequently quinazolinone
and benzofuran were joined to each other and finally the imidazole ring was placed on the
This article is protected by copyright. All rights reserved.

1
benzofuran-quinazolinone structure (Scheme 1). After characterization by IR, H-NMR and
elemental analysis, these compounds were screened for antibacterial and anti-fungal activities
using Alamar blue susceptibility test (MABA) method. Cytotoxic activities of the synthesized
hybrid compounds were also examined by MTT assay on human breast cancer cell line
(MCF-7).
This article is protected by copyright. All rights reserved.

O
O
R1
O
R1
Acetone
H
CH3
Cl
+
O
Reflux
10-12 h
OH
3a-c
2
1a-c
3a-c
O
O
R1
R1
Br2, AcOH
1-2 h R.T.
Br
CH3
O
O
4a-c
O
O
COOH
NH2
R2
R2
H
NH2
NH
6
10-12 h R.T.
N
5a-c
7a-c
O
O
R1
R2
NH
N
Br
R1
+
O
N
KOtbu
O
NaBH4, MeOH
R2
Reflux
10-12 h
N
O
R. T.
12 h
4a-c
O
7a-c
8a-i
R1
O
N
R1
O
N
R2
SOCl2
R2
N
O
N
O
OH
Reflux
5-7 h
Cl
10 a-i
9a-i
MeCN, reflux
24-36 h
N
N
11
R1
O
R2
N
O
N
Cl-
N
a: R1= H, R2 = H;
d: R1= Br, R2 = H;
b: R1= H, R2 = Cl;
c: R1= H, R2= OCH3
f: R1= Br, R2 = OCH3
N
e: R1 = Br, R2 = Cl;
g: R1= OCH3, R2 = H; h: R1 = OCH3, R2 = Cl; i: R1= OCH3, R2= OCH3
12a-i
Scheme 1. Synthesis of the quinazolinone, benzofurane and imdazoliuom hybrids.
This article is protected by copyright. All rights reserved.

Results and discussion
Chemistry
In the present work, nine novel hybrid compound of quinazolinone, benzofuran and
imidazole were designed based on pharmacophoric hybridization method and were
synthesized according to the procedure described below, and is shown in Scheme 1.
In the first part of the study, chloroacetone (2) was added to a mixture of
salicylaldehyde derivatives (1a-c) and anhydrous potassiuom carbonate in acetone. After
completion of the reaction, the mixture was filtered to get clear solution and then
concentrated by distillated under reduced pressure to obtain transparent crystals of 2-acethyl
benzofurans (3a-c) which were brominated with Br2 in acetic acid at room temperature in
good yields (4a-c) [32]. On the other hand, the cyclization of the anteranilic acid and its
derivatives (5a-c) was used as an excellent strategy for the synthesis of quinazolinone core
(7a-c) [33]. Subsequently, the nucleophilic attack of quinazolinone (7a-c) to bromomethyl
ketone benzofurans (4a-c) in dry THF, in the presence of K-tBuO produced the benzofuran-
quinazolinone hybrids (8a-i) as an insoluble substance in reaction mixtures. Consequently,
the reduction of benzofuran-quinazolinone hybrids (8a-i) by sodium brohydride (NaBH4) was
also evaluated which resulted in selective reductions of ketones in the presence of amide unit
in quinazolinones (9a-i). After extraction of product with chloroform, the solvent was
evaporated under reduced pressure and the residual mass was chlorinated with thionyl
chloride in dichloromethane to convert hydroxyl group into chlorid as a better leaving group
(10a-i). Finally, chlorinated compounds were reacted with methyl imidazole (11) in
acetonitril at reflux temperature. The final products (12a-i) were formed as an insoluble
substance in reaction mixture which was filtered and characterized with different techniques
(Schemes 1).
This article is protected by copyright. All rights reserved.

FT-IR characterization
The structures of synthesized compounds were confirmed by means of FT-IR spectroscopy.
The main IR vibrational bands of the synthesized compounds were found in their expected
regions. In FT-IR spectra of 2-acetyl benzofurans derivatives, C=O (ketone) group appeared
around 1698-1710 cm−1. The peaks at 1501-1590 and 1324-1368 confirm the presence of
C=C and C-O groups, respectively. Bromination of 2-acethyl benzofuran derivatives with
bromine in acetic acid resulted in a new band in 828-843 which was assigned to the vibration
of C-Br. On the other hand, FT-IR of synthesized quinazolinones also exhibited absorptions
at 1657-1680 and 3295-3335 cm-1 which indicate the presence of the heterocyclic amide and
NH in the structures. The formation of quinazolinon-benzofuran hybrid products was
confirmed by the absence of bands at 3295-3335 cm-1 originally attributed to stretching
vibrations of NH of quinazolinons and instead, two strong band appeared at 1697-1718 and
1663-1675 cm-1 confirming the presence of both ketone and amid in molecules framework.
After reduction with NaBH4, a new band, observed at 33310-3370 cm-1 was assigned to the
vibration of hydroxyl group in the spectrum of the product, confirming formation of hydroxyl
group. This peak disappears in chloro derivatives, caused by chlorination via SoCl2. Reaction
of methyl imidazole with chloro intermediates resulted in desired products which were
characterized with FT-IR as mentioned below. The vibration at 1664-1686 cm-1 was assigned
to carbonyl group. The absorption bands appeared around 3051-3141 and 2837-2952 cm−1
are related to the corresponding aromatic and aliphatic C-H stretching vibration, respectively.
IR bands emerging at 1635-1645 and 1248-1284 cm-1 were attributed to the C=N and C-O
vibrations of hybrid product in all the spectra. In the spectrum of the final products compare
with earlier intermediate, a brief widening was observed. This flattening can be attributed to
existence of new bands, related to imidazole moiety.
This article is protected by copyright. All rights reserved.

NMR characterization
1
The H NMR spectral data of the intermediate and final products recorded in DMSO-d6
and/or CDCl3 along with its possible assignments was reported in the experimental part. All
the aromatic and aliphatic protons were found in their expected region. 2-Acethyl
benzofurane derivatives possessed a singlet at 2.58–2.65 ppm due to three protons of acethyl
moiety and also aromatic protons of benzofuran were found in the region at 6.68-7.77 ppm.
The NH proton of quinazolinone ring exhibited a broad singlet at 9.46 ppm. The absorption
of aromatic protons of quinazolinone appeared in the range of 7.40-8.32 ppm. By situation of
these two pharmacophores next to each other, no peak appeared for NH and the peaks of the
rest of the molecule have emerged in their region. After reduction of carbonyl group with
NaBH4, the new hydroxyl (OH) proton in the compounds was observed at 5.21-5.33 ppm as a
broad singlet peak and the germinal CH proton was found at 4.19-5.15 ppm as a triplet. In
these compounds, CH2 appeared as a doublets peak at 3.98-4.96 ppm, which had already been
seen as single peak. In the final product, appearances of the methyl (CH3) protons of
imidazole at 2.71-2.93 ppm as a single peak and moreover, the number of protons calculated
from the 1H NMR integration curves strongly confirmed the attachment of methyl imidazole
on benzofurane-quinazolinone hybrid. It should be mentioned that the protons of methoxy
substitution on the rings, present in derivatives, were found in the region at 3.75-3.84 ppm
and chloro substitution cause slightly change in chemical shift of protons. In sum, NMR
curves were having characteristic peak for synthesized hybrid compounds.
Biological evaluation
Antimicrobial activity
All newly synthesized 1-[(1-(benzofuran-2-yl)-2-(quinazolin-4(3H)-one-3-yl)]ethyl-1-yl]-3-
methyl imidazol-1-ium chloride derivatives were evaluated for their in vitro antibacterial and
antifungal activity, using Alamar blue susceptibility test (MABA) method [34, 35], against
This article is protected by copyright. All rights reserved.

three gram positive bacteria (Staphylococcus aureus PTCC 1337, Bacillus subtilis PTCC
1023, Listeria monocitogenes PTCC 1165) and three Gram-negative bacteria: (Escherichia
coli PTCC 1338, Pseudomonas aeruginosa PTCC 1074, Salmonella entritidis PTCC 1091)
and also yeast-like fungi (Candida albicans PTCC 5027) strains. Ciprofloxacin and
Ketoconazole were used as the reference antibacterial and antifungal drugs for comparison.
In vitro antibacterial activity of synthesized derivatives were showed in table 1-3 and resulted
in the following observations:
1. In general all the tested compounds (12a-i) possessed good deal of antibacterial
activity against gram positive (especially Staphylococcus aureus) and gram negative
bacteria as compared to the standard drug Ciprofloxacin.
2. Most of substituted analogs, except derivatives with two methoxy groups, showed
slightly higher activity when compared to unsubstituented analogs and had similar
antimicrobial activity. This similarity among the evaluated analogs might be mainly
due to the same substitution pattern on the benzofuran and quinazolinone rings.
3. It is noteworthy that, among the nine active compounds, 12e with two halogen atoms,
was found to be the most potent member producing the lowest amounts of MIC
against tested microorganism (MIC=16 µg/ml) when compared to other derivatives.
Structural elucidation indicated that halogen atoms on benzofuran and quinazolinone
rings might be responsible for higher activity of compounds 5e which is similar to
what was observed in benzufuran containing natural products [36]. One possible
reason may be related to increased hydrophobicity in these compounds.
4. Compound 12i had two methoxy substitutions on its structure and showed lowest
antimicrobial activity. This might be related to the decreased lipophilicity of the
This article is protected by copyright. All rights reserved.

compound due to the presence of methoxy group at C-5 and C-6 position of
benzofuran and qunazolinone heterocyclic rings, respectively.
5. Generally, the synthesized compounds were more effective against Gram-positive
bacteria (especially Staphylococcus aureus) with MIC in the range of 256–16 µg/ml
and showed the least antibacterial activity against E. coli (gram negative bacteria). In
case of E. coli the compounds 12a, 12c, 12f, 12g and 12i showed no antibacterial
activity
6. The obtained results of MBC revealed that tested compounds have more significant
bacteriostatic than bactericidal activities (Tables 1 and 2).
7. In case of antifungal activity against Candida albicans, the synthesized compounds
produced moderate to good activity (Table 3) and again compound 12a and 12e was
found to be most potent members showing lower MIC=128 µg/ml . In general
antifungal activity was lower than antibacterial activity.
8. The obtained results of MFC revealed that tested compounds have more significant
fungistatic than fungicidal activities (Tables 3).
Table 1. MIC and MBC of the synthesized compounds (12a-i) against Gram-negative
bacteria
Gram-negative bacteria (µg/ml)
Escherichia
coli
Pseudomonas
aeruginosa
Salmonella
entritidis
Compound
MIC MBC
MIC
512
256
G
256
128
256
512
512
G
MBC
NA
NA
NA
NA
512
512
NA
NA
NA
-
MIC
MBC
NA
512
NA
512
256
NA
512
NA
NA
-
G
512
G
NA
NA
NA
NA
512
NA
NA
NA
NA
-
512
256
512
128
128
512
256
512
512
4
12a
12b
12c
12d
12e
12f
12g
12h
12i
512
128
G
G
512
G
Ciprofloxacin
8
4
G: Growth of bacteri
NA: Not applicable
(-):Not measured
This article is protected by copyright. All rights reserved.

Table 2. MIC and MBC of the synthesized compounds (12a-i) against Gram-positive
bacteria
Compound
Gram-positive bacteria (µg/ml)
Staphylococc
us aureus
Bacillus
subtilis
Listeria
monocitogenes
MIC MBC MIC
MBC
512
256
512
256
128
512
NA
512
512
-
MIC
128
256
256
128
128
512
256
256
512
8
MBC
512
512
512
256
256
NA
512
ND
ND
-
128
64
512
256
256
512
128
NA
512
512
NA
-
256
32
12a
12b
12c
12d
12e
12f
12g
12h
12i
128
128
16
128
128
32
512
128
256
512
4
256
512
256
128
4
Ciprofloxacin
NA: Not applicable
(-):Not measured
Table 3. MIC and MFC of the synthesized compounds (12a-i) against Candida albicans
Candida albicans (µg/ml)
Compound 12a
12b
256
512
12c
256
NA
12d
256
512
12e
128
512
12f
256
512
12g
512
NA
12h
256
512
12i
256
NA
128
512
MIC
MFC
Ketoconazol (standard antifungal agent with MIC= 8 µM)
NA: Not applicable
Cytotoxic activity
All the synthesized compounds were evaluated for their cytotoxic effects on MCF-7 breast
cancer cell line at 0.1, 1, 10 and 100 µM concentrations using MTT assay [37, 38]. The
concentration dependent cytotoxicity of this scaffold against MCF-7 cell line was shown in
Table 4. The results showed that the synthesized derivatives showed significant differences in
viability (p≤ 0.05) and the following observations were found:
1. Most of the synthesized compounds are active against MCF-7 cell line but only one of
the tested compounds viz. 12e didn’t showed any cytotoxic activity.
This article is protected by copyright. All rights reserved.

2. According to the obtained results, compounds 12i, 12c and 12g showed IC50 around
0.57, 1 and 1µM, respectively while compounds 12a and 12b exhibiting IC50 values
below 10 µM.
3. The presence of methoxy substituent on heterocyclic ring seems to play an important
role on the observed growth inhibition. The favorable effect of methoxy group on
activity profiles is authenticated on comparing 12a, 12g and 12i
4. Decrease in activity has been observed especially when halogen substituted rings was
employed. Such that, the compounds 12e with two halogen group showed no
cytotoxic effect on cancerous cells in each of the examined concentrations.
5. The most active compound among the series was 12i, which had shown more %
growth inhibition than Doxorubicin in concentration of 0.1 µM on MCF-7 cells. This
data certainly reveals the great potential of the compound 12i as an effective cytotoxic
agent.
Table 4. In vitro cytotoxic activity of synthesized compounds against MCF-7 cells
Compound
IC50(µM)
Concentration
(µM)
%survival
P value
12a
7.70
0.1
1
87.94 7.85
79.93 7.29
21.1 7.67
0.87 0.76
0.020
0.047
0.031
0.008
10
100
This article is protected by copyright. All rights reserved.

12b
12c
12d
12e
12f
12g
9.14
1.00
20.58
NT
0.1
1
NT
80.00 1.73
46.86 2.57
17.3 3.23
74.33 8.66
49.43 4.41
10.26 5.89
0.00 0.00
NT
ND
0.026
0.028
0.040
0.019
0.034
0.025
0.046
ND
10
100
0.1
1
10
100
0.1
1
NT
ND
0.032
0.001
ND
10
100
0.1
1
56.66 2.08
0.00 0.00
NT
NT
NDc
10
100
0.1
1
NT
ND
NT
ND
73.26
1.00
NT
ND
NT
ND
10
100
0.1
69.16 1.25
41.90 3.143
90.05 6.60
0.047
0.038
0.031
1
51.66 3.05
0.018
0.041
10
43.16 4.75
This article is protected by copyright. All rights reserved.

0.043
ND
100
0.1
1
0.00 0.00
NT
12h
100.00
NT
ND
10
94.63 2.28
0.034
0.050
0.019
0.028
0.031
0.038
NDc
100
0.1
1
56.00 6.28
56.63 5.82
44.16 4.04
4.06 2.99
12i
0.57
3.62
10
100
0.5
0.70 3.212436
59.70 4.27
Doxorubicin
(NT) No toxicity was observed
(ND) Not determined
Docking study
According to cytotoxic study on MCF-7 cell line, some of the novel hybrid compounds could
be used as new potential anti-breast cancer agents. High expression of aromatase in this
human breast cancer cells encouraged us to study the interaction of cytotoxic hybrids
compounds with crystal structure of aromatase through docking simulation. According to
previous study [39], polarization the effects can play a significant role in determining
structures of protein-ligand complexes. In this study, due to the presence of Heme in the
active site of the enzyme and also the positive charge on the imidazolium ring, the ligands
were optimized inside the protein through QM/MM calculations and more accurate atomic
charges of ligands obtained according to polarized active site of enzyme [39, 40]. Fixed
charges of ligands in docking procedure, obtained from force field parameterization, are
This article is protected by copyright. All rights reserved.

replaced by those one obtained by QM/MM calculations in the protein environment and the
redocking was performed. Molecular modeling studies have revealed that these novel hybrid
compounds could fit the hydrophobic cavity in aromatase and the substituated methoxy group
in their structure interacts with residue around the pocket. Among three heterocyclic rings,
quinazolinone nucleus was oriented to the Heme which provided hydrophobic interaction
between quinazolinone moieties and Heme porphyrins. The highly hydrophobic pockets
composed of Phe134, Val370, Leu477, Thr310, Val369 and Trp224 were formed very
favorable hydrophobic interactions with benzofuran and imidazole moieties (Fig. 1). Hybrid
containing methoxy substituent on quinazolinone establishes hydrogen bond with Asp309
residue (Fig. 2), while the amino acid Ser 478 was found to play an important role in
hydrogen bond interactions with methoxy substituent on benzofuran ring (Fig. 3). The free
energies of binding (ΔGb) and inhibition constants (Ki) as calculated by AutoDock are
summarized in Table 5. The result showed that these novel hybrid compounds were adopted
properly within the aromatase binding site, suggesting that they could be potential inhibitors
of aromatase.
Fig. 1. The binding mode of synthesized hybrid scaffold (compound 12a) in active site of
aromatase obtained from autodock4 (a) 3D structure and (b) 2D structure
This article is protected by copyright. All rights reserved.

Fig. 2. The binding modes and hydrogen bonds interactions of methoxy group on
quinazolinone ring (compound 12c) with Asp309 in the aromatase active site (a) 3D structure
and (b) 2D structure
Fig. 3. The binding modes and hydrogen bonds interactions of methoxy group on benzofuran
ring (compound 12g) with Ser 478 in the aromatase active site (a) 3D structure and (b) 2D
structure
This article is protected by copyright. All rights reserved.

Table 5. Chemical structures and the free binding energy (kcal/mol) as well as inhibition
constants (Ki) of cytotoxic ligands after refitting the charges calculated by AutoDock.
Z
N
O
N
Y
X
N
O
N
E
Binding
No
X
Y
Z
E
cluster
Ki
energy(3)
-7.65
-7.10
-7.80
-7.62
-7.38
-7.48
-7.93
-8.46
12a
12b
12c
12d
12f
H
H
H
methyl
methyl
methyl
methyl
methyl
methyl
methyl
methyl
methyl
methyl
42
39
5
17.74 µM
5.73 µM
2.00 µM
3.10 µM
6.30 µM
15.56 µM
1.30 µM
602.00nM
Cl
H
methoxy methyl
methyl
methoxy methyl
Br
Br
H
50
40
53
36
38
12g methoxy
12h methoxy
H
methyl
methyl
Cl
12i methoxy methoxy methyl
Conclusions
In summary, a series of novel 1-[[(1-(benzofuran-2-yl)-2-(quinazolin-4(3H)-one-3-yl)]ethyl-
1-yl]-3- methyl imidazol-1-ium chloride derivatives were designed via molecular
hybridization approach and synthesized through routine chemical methods. Antimicrobial
evaluation data revealed that, in general most of the tested compounds possessed good
antibacterial activity against selected gram positive bacteria and candida albicance as
compared to the standard drugs. Among all the tested compounds, compound 12e, with two
This article is protected by copyright. All rights reserved.

halogen atoms, exhibited significantly greater antibacterial and antifungal activities.
Cytotoxic effect of the synthesized compounds was also investigated on MCF-7 breast cancer
cell using MTT assay. The results showed that the introduction of methoxy group on
quinazolinone and benzofuran skeletons increased the cytotoxicity behavior of synthesized
compounds, while decrease in activity was observed especially when halogen substituted
rings was employed. Compound 12i was the most active derivative among these series and
showed more growth inhibition than doxorubicin in concentration of 0.1 µM on MCF-7 cells.
Molecular modeling studies of the cytotoxic compounds with aromatase, as an enzyme that is
highly expressed in MCF-7 cell line, have revealed that these novel hybrid compounds could
be well accommodated in the hydrophobic cavity of aromatase and the substituted methoxy
group in their structure interacts with the residues around the pocket.
Experimental
Materials and methods
All the chemicals were obtained from Merck and Sigma–Aldrich as ‘synthesis grade’. All the
experiments were monitored by analytical thin layer chromatography (TLC) using several
solvent systems of different polarity on pre-coated silica gel 60 F254 aluminum plates
(Merck, Germany). Melting points were determined on Electrothermal 9200 melting point
apparatus. The IR spectra were recorded as potassium bromide pellets using a JASCO 6300
(Japan) FTIR spectrometer. 1H NMR spectra in CDCl3 and/or DMSO-d6 solution were taken
on Bruker (400.13 MHz at 25°C) spectrometers using TMS as internal standard. All chemical
shift values were measured as δ (ppm). Splitting patterns are as follows: s, singlet; d, doublet;
m, multiplet b, broad and dd, doublet of doublet. Elemental analysis was performed using
CHNS-923 LECO analyzer and the results were within 0.4% of the theoretical values.
Suitable names for all the novel compounds were given with the aid of ChemOffice2010.
This article is protected by copyright. All rights reserved.

General procedure for the synthesis of (benzofuran-2-yl)ethanone derivatives (3a-c)
Chloroacetone (2, 3.5 mmol) was added to salicylaldehyde derivatives (1a-c, 3.0mmol) in
mixture acetone (15 mL) and anhydrous potassiuom carbonate (7.0 mmol), and the mixture
was stirred under reflux condition for an appropriate time. The reaction progress was
monitored using TLC. Upon completion, the potassium carbonate was filtered off by funnel,
then solvents were evaporated under vacuum and the crude was recrystallized using
petroleum ether [32].
1-(Benzofuran-2-yl)ethanone (3a)
Transparent crystals, Yield: 75%, m.p.: 79.0-79.5°C (lit. [32], m.p.:78°C), FT-IR (KBr) ν
(cm-1): 3021.34 (C-H, aromatic), 2812.92 (C-H, aliphatic), 1698.44 (C=O, ketone), 1544.77,
1
1501.28 (C=C, aromatic), 1324.75 (C-O), H NMR (DMSO-d6) δ (ppm): 2.58 (3H, s, CH3),
6.68 (1H, s, aromatic), 7.28–7.47 (2H, m, aromatic), 7.54 (1H, d, aromatic, J=7.20 Hz), 7.68
(1H, d, aromatic, J=7.10 Hz).
1-(5-Bromobenzofuran-2-yl)ethanone (3b)
White solid, Yield: 85%, m.p.: 110°C, FT-IR (KBr) ν (cm-1): 3106.34 (C-H, aromatic),
2932.92 (C-H, aliphatic), 1710.21 (C=O, ketone), 1590.63, 1571.70 (C=C, aromatic),
1368.55(C-O), 864.25 (C-Br)., 1H NMR (DMSO-d6) δ (ppm): 2.65(3H, s, CH3), 7.41 (1H, s,
aromatic), 7.47 (1H, d, aromatic, J=6.90 Hz), 7.54 (1H, d, aromatic, J=6.90 Hz), 7.77 (1H, s,
aromatic).
1-(5-Methoxybenzofuran-2-yl)ethanone (3c)
This article is protected by copyright. All rights reserved.

Light yellow crystal, Yield: 80%, m.p.: 91-92 °C, FT-IR (KBr) ν (cm-1): 3091.34 (C-H,
aromatic), 2928.92 (C-H, aliphatic), 1705.54 (C=O, ketone), 1568.13, 1521.36 (C=C,
1
aromatic), 1335.74 (C-O), H NMR (DMSO-d6) δ (ppm): 2.64 (3H, s, CH3), 3.75 (3H, s,
OCH3), 6.94 (1H, s, aromatic), 7.18 (1H, d, aromatic, J=7.10 Hz), 7.28 (1H, d, aromatic,
J=7.10 Hz), 7.47 (1H, s, aromatic).
General procedure for the synthesis of (1-Benzofuran-2-yl)-2-bromoethanone derivatives
(4a-c)
Substituted 2-acetyl benzofurans (3a-c) was brominated through reaction with bromine in
acetic acid. A solution of bromine (2.1 mmole) in acetic acid (10 mL) was slowly added to a
solution of substituted 2-acetyl benzofuran (3a-c, 2.0 mmol) in acetic acid for about 15-20
min while the mixture was stirred in room temperature. After addition of bromine, the
mixture was stirred for 45-75 min. Completion of reaction was monitored by TLC. Then the
mixture was decanted in crushed ice, the solid separated was collected and recrystallized
from ethanol [32].
1-(1-Benzofuran-2-yl)-2-bromoethanone (4a)
Light green crystals, Yield: 80%, m.p.: 93-94°C (lit. [32]; m.p.:94°C), FT-IR (KBr) ν (cm-1):
3101.04 (C-H, aromatic), 2935.12 (C-H, aliphatic), 1708.31 (C=O, ketone), 1584.21, 1573.85
1
(C=C, aromatic), 1320.75 (C-O), 831.13 (C-Br), H NMR (DMSO-d6) δ (ppm): 4.37 (2H, s,
CH2), 7.21 (1H, s, aromatic), 7.575-7.617 (2H, m, aromatic), 7.78 (1H, d, aromatic, J=7.10
Hz), 7.83 (1H, d, aromatic, J=7.30 Hz).
This article is protected by copyright. All rights reserved.

Bromo-1-(5-bromo-1-benzofuran-2-yl) ethanone (4b)
White solid, Yield: 76%, m.p.:140–142°C, FT-IR (KBr) ν (cm-1): 3111.04 (C-H, aromatic),
2942.93 (C-H, aliphatic), 1720.65 (C=O, ketone), 1612.14, 1575.24 (C=C, aromatic),
1
1371.11 (C-O), 857.41 (C-Br), H NMR (DMSO-d6) δ (ppm): 4.55(2H, s, CH2), 7.48 (1H, s,
aromatic), 7.58 (1H, d, aromatic, J=7.10), 7.63 (1H, d, aromatic, J=7.10 Hz), 8.13 (1H, s,
aromatic).
2-Bromo-1-(5-methoxybenzofuran-2-yl)ethanone (4c)
Yellow crystal, Yield: 70%, m.p.: 115–116°C, FT-IR (KBr) ν (cm-1): 3095.63 (C-H,
aromatic), 2938.25 (C-H, aliphatic), 1711.05 (C=O, ketone), 1612.36, 1573.72 (C=C,
aromatic), 1357.88 (C-O), 844.21 (C-Br), 1H NMR (DMSO-d6) δ (ppm): 3.83 (3H, s, OCH3),
4.44 (2H, s, CH2), 7.04 (1H, s, aromatic), 7.34 (1H, d, aromatic, J=7.00 Hz), 7.49 (1H, d,
aromatic, J=6.90 Hz), 7.63 (1H, s, aromatic).
General procedure for the synthesis of quinazolin-4(3H)-one derivatives (7a-c)
The mixture of anthranilic acid derivatives (5a-c, 6 mmo1) and formamide (6, 24 mmol) was
stirred at 145-165 °C for 8-12 h. The progress of reaction was monitored by TLC. After
completion of reaction, the mixture was cooled and glacial water (15 m1) was added. A lot of
solid appeared immediately. The mixture was stirred for another 30 min. The resulting
precipitate was filtered and recrystallized with ethanol to give quinazolinon derivatives (7a-c)
[33].
Quinazolin-4(3H)-one (7a)
White solid, yield: 92%, m.p.:216-217°C (lit. [33]; m.p.:215°C). FT-IR (KBr) ν (cm-1):
3340.88 (N-H), 3095.63 (C-H, aromatic), 1657.43 (C=O), 1583.82 (C=C, aromatic), 1602.46
This article is protected by copyright. All rights reserved.

1
(C=N). H NMR (DMSO-d6) δ (ppm): 7.40-7.45 (2H, m, aromatic), 7.78 (1H, d, aromatic,
J=7.40 Hz), 7.91 (1H, d, aromatic, J=7.10 Hz), 8.10 (1H, s, aromatic), 12.29 (1H, broad,
NH).
6-Chloroquinazolin-4(3H)-one (7b)
White solid, yield: 80%, m.p.: 259-260°C (lit. [41]; m.p.: 257-260°C). FT-IR (KBr) ν (cm-1):
3295.11 (N-H), 3102.37 (C-H, aromatic), 1680.71 (C=O), 1603.10 (C=C, aromatic), 1611.46
1
(C=N). H NMR (DMSO-d6) δ (ppm): 7.75 (1H, d, aromatic, J=6.70 Hz), 7.90 (1H, d,
aromatic, J=6.70 Hz), 8.11 (1H, s, aromatic), 8.32 (1H, s, aromatic), 12.67 (1H, broad, NH).
6-Methoxyquinazolin-4(3H)-one (7c)
White solid, yield: 75%, m.p.; 243°C. FT-IR (KBr) ν (cm-1): 3355.73 (N-H), 3099.63 (C-H,
aromatic), 1662.48 (C=O), 1591.55 (C=C, aromatic), 1609.13 (C=N). 1H NMR (DMSO-d6) δ
(ppm): 3.85 (3H, s, OCH3), 7.63 (1H, d, aromatic, J=7.10 Hz), 7.81 (1H, d, aromatic, J=7.10
Hz), 8.00 (1H, s, aromatic), 8.21 (1H, s, aromatic), 12.49 (1H, broad, NH).
General procedure for the synthesis of 3-(2-(benzofuran-2-yl)-2-oxoethyl)quinazolin-4(3H)-
one derivatives (8a-i)
Quinazolinon derivatives (5 mmol) were added to a mixture of potassium tert-
butoxide (5 mmol) in THF (5 ml) and then bromoacetylbenzofurans (5mmol) was added to
the mixture with stirring. The reaction is lasted for 6-9 h at reflux temperature. Over time,
product was formed as an insoluble substance which had distinctly different Rf on the TLC
plate compare to initial compounds. The resulting precipitate was filtered and recrystallized
with chloroform and n-heptane to give desired compound.
This article is protected by copyright. All rights reserved.

3-(2-(Benzofuran-2-yl)-2-oxoethyl)quinazolin-4(3H)-one (8a)
White solid, yield: 55%, m.p.:120-121°C.FT-IR (KBr) ν (cm-1): 3067.18, 3019.37 & 2890.59
(C-H, aromatic & aliphatic), 1695.84 (C=O), 1664.69 (C=O), 1631.39 (C=N), 1251.49 (C-
O).1H NMR (DMSO-d6) δ (ppm): 4.14 (2H, s, CH2), 6.96 (1H, s, aromatic), 7.21-7.53 (5H,
m, aromatic), 7.69-7.75 (2H, m, aromatic), 7.95 (1H, d, aromatic, J=7.30 Hz), 8.13 (1H, s,
aromatic).
3-(2-(Benzofuran-2-yl)-2-oxoethyl)-6-chloroquinazolin-4(3H)-one (8b)
White solid, yield: 48%, m.p.:130-132°C. FT-IR (KBr) ν (cm-1): 3105.93, 3074.21& 2930.42
(C-H, aromatic & aliphatic),1712.08 (C=O), 1666.95 (C=O), 1649.16 (C=N), 1280.33 (C-
O).1H NMR (CDCl3) δ (ppm): 4.53 (2H, s, CH2), 7.05 (1H, s, aromatic), 7.25-7.31 (2H, m,
aromatic), 7.54-7.70 (3H, m, aromatic), 7.90(1H, d, aromatic, J=7.20 Hz), 8.11 (1H, s,
aromatic), 8.32(1H, s, aromatic).
3-(2-(Benzofuran-2-yl)-2-oxoethyl)-6-methoxyquinazolin-4(3H)-one (8c)
White solid, yield: 57%, m.p.:110-112°C. FT-IR (KBr) ν (cm-1): 3089.11, 3068.31, 2982.42
(C-H, aromatic& aliphatic), 1707.38 (C=O), 1665.90 (C=O), 1648.41 (C=N), 1240.93 (C-
O).1H NMR (DMSO-d6) δ (ppm): 3.86 (3H, s, OCH3), 4.38 (2H, s, CH2), 6.83 (1H, s,
aromatic), 7.27-7.33 (2H, m, aromatic), 7.55-7.72 (3H, m, aromatic), 7.87(1H, s, aromatic),
7.98 (1H, s, aromatic), 8.19(1H, s, aromatic).
3-(2-(5-Bromobenzofuran-2-yl)-2-oxoethyl)quinazolin-4(3H)-one (8d)
Greenish yellow needles yield: 65%, m.p.:135-136°C. FT-IR (KBr) ν (cm-1): 3098.23,
3080.31& 2954.18 (C-H, aromatic & aliphatic), 1715.41 (C=O), 1663.59 (C=O),
This article is protected by copyright. All rights reserved.

1622.17(C=N), 1236.11 (C-O).1H NMR (CDCl3) δ (ppm): 4.83 (2H, s, CH2), 7.47 (1H, s,
aromatic), 7.56-7.69 (5H, m, aromatic), 7.80 (1H, d, aromatic, J=7.30 Hz), 7.94 (1H, s,
aromatic), 8.13(1H, s, aromatic).
3-(2-(5-Bromobenzofuran-2-yl)-2-oxoethyl)-6-chloroquinazolin-4(3H)-one (8e)
Pale yellow crystals, yield: 63%, m.p.:127-129°C. FT-IR (KBr) ν (cm-1): 3111.43, 3083.42 &
2962.78 (C-H, aromatic & aliphatic), 1718.46 (C=O), 1675.59 (C=O), 1629.67 (C=N),
1240.71 (C-O).1H NMR (CDCl3) δ (ppm): 5.01 (2H, s, CH2), 7.42-7.51 (3H, m, aromatic)
7.72 (1H, d, aromatic, J=6.80 Hz), 7.91 (1H, s, aromatic), 8.1 (1H, s, aromatic), 8.15 (1H, d,
aromatic, J=6.80 Hz), 8.23 (1H, s, aromatic).
3-(2-(5-Bromobenzofuran-2-yl)-2-oxoethyl)-6-methoxyquinazolin-4(3H)-one (8f)
White solid, yield: 65%, m.p.:133-134°C. FT-IR (KBr) ν (cm-1): 3088.29, 3077.81& 2882.69
(C-H, aromatic & aliphatic), 1711.26 (C=O), 1663.92 (C=O), 1598.86 (C=N), 1270.71 (C-
O).1H NMR (CDCl3) δ (ppm): 3.81 (3H, s, OCH3), 4.96 (2H, s, CH2), 7.23-7.47 (5H, m,
aromatic), 7.61 (1H, s, aromatic), 8.05 (1H, s, aromatic), 8.25(1H, s, aromatic).
3-(2-(5-Methoxybenzofuran-2-yl)-2-oxoethyl)quinazolin-4(3H)-one (8g)
White solid, yield: 56%, m.p.:140-141°C. FT-IR (KBr) ν (cm-1): 3080.41, 3069.99& 2915.27
(C-H, aromatic & aliphatic), 1697.88 (C=O), 1667.36 (C=O), 1604.70 (C=N), 1293.28 (C-
O).1H NMR (CDCl3) δ (ppm): 3.75 (3H, s, OCH3), 4.39 (2H, s, CH2), 6.65 (1H, s, aromatic),
6.93 (1H, s, aromatic), 7.15-7.21 (2H, m, aromatic), 7.60-7.71 (3H, m, aromatic), 8.12 (1H, d,
aromatic, J=7.10 Hz), 8.21( 1H, s, aromatic).
This article is protected by copyright. All rights reserved.

6-Chloro-3-(2-(5-methoxybenzofuran-2-yl)-2-oxoethyl)quinazolin-4(3H)-one (8h)
Pale yellow crystals, yield: 63%, m.p.:136-138°C. FT-IR (KBr) ν (cm-1): 3114.34, 3034.67 &
2938.41 (C-H, aromatic & aliphatic), 1705.95 (C=O), 1671.73 (C=O), 1612.09 (C=N),
1283.39 (C-O).1H NMR (CDCl3) δ (ppm): 3.81 (3H, s, CH3), 4.62 (2H, s, CH2), 6.67(1H, s,
aromatic), 6.94 (1H, s, aromatic), 7.12-7.22 (2H, m, aromatic), 7.75 (1H, d, aromatic, J=7.10
Hz), 7.90 (1H, s, aromatic), 8.20 ( 1H, d, aromatic, J=7.10 Hz), 8.29 ( 1H, s, aromatic).
6-Methoxy-3-(2-(5-methoxybenzofuran-2-yl)-2-oxoethyl)quinazolin-4(3H)-one (8i)
Bright yellow needles, yield: 69%, m.p.:137-139°C. FT-IR (KBr) ν (cm-1): 3038.98,
3029.94& 2893.50 (C-H, aromatic & aliphatic), 1697.84 (C=O), 1665.69 (C=O), 1651.38
(C=N), 1257.69 (C-O).1H NMR (CDCl3) δ (ppm): 3.75 (3H, s, CH3), 3.81 (3H, s, CH3), 4.55
(2H, s, CH2), 6.65(1H, s, aromatic), 6.91 (1H, s, aromatic), 7.07-712 (2H, m, aromatic), 7.65-
7.79 (2H, dd, aromatic, J=6.90 Hz), 7.86 (1H, s, aromatic), 8.20 ( 1H, s, aromatic).
General procedure for the synthesis of 3-(2-(benzofuran-2-yl)-2-hydroxyethyl)quinazolin-
4(3H)-one derivatives (9a-i)
NaBH4 (5 mmol) was slowly added to a vigorously stirred solution of 3-(2-(benzofuran-2-yl)-
2-oxoethyl)quinazolin-4(3H)-one derivatives (5 mmol) in methanol (15 mL) at 0 °C. The
reaction mixture was allowed to stand at room temperature over a period of 14 h while
monitored on TLC. The reaction was quenched by adding diluted HCl (1:5, 4 mL) and the
product was extracted to chloroforam (3×20). Organic phase was collected, washed with
water (3×20) and the solvents were removed under vacuum. Crude product was crystallized
from ethanol to give 3-(2-(benzofuran-2-yl)-2-hydroxyethyl)quinazolin-4(3H)-one
derivatives (9a-i).
This article is protected by copyright. All rights reserved.

2-(Benzofuran-2-yl)-2-hydroxyethyl)quinazolin-4(3H)-one (9a)
White solid, yield: 66%, m.p.:98-100°C.FT-IR (KBr) ν (cm-1): 3310 (OH), 3059.47, 3020.37
& 2856.17 (C-H, aromatic & aliphatic), 1664.69 (C=O), 1639.84 (C=N), 1250.41 (C-O).1H
NMR (DMSO-d6) δ (ppm): 3.98 (2H, d, CH2, J=7.40 Hz), 4.19 (1H, t, CH, J=7.40 Hz),
5.21(1H, brs, OH), 6.68 (1H, s, aromatic), 7.14-7.26 (2H, m, aromatic), 7.43 (1H, d,
aromatic, J=7.10 Hz), 7.58-7.79 (4H, m, aromatic), 7.97 (1H, d, aromatic, J=7.30 Hz),
8.15(1H, s, aromatic).
3-(2-(Benzofuran-2-yl)-2-hydroxyethyl)-6-chloroquinazolin-4(3H)-one (9b)
White solid, yield: 76%, m.p.:104-105°C.FT-IR (KBr) ν (cm-1): 3340 (OH), 3098.33,
3058.94 & 2898.12 (C-H, aromatic& aliphatic), 1665.41 (C=O), 1650.48 (C=N), 1268.36 (C-
O).1H NMR (CDCl3) δ (ppm): 4.48 (2H, d, CH2, J=7.20 Hz), 4.59 (1H, t, CH, J=7.20 Hz),
5.28(1H, brs, OH), 6.56 (1H, s, aromatic), 7.21-7.50 (4H, m, aromatic), 7.82(1H, d, aromatic,
J=6.80 Hz), 7.93 (1H, s, aromatic), 8.10 (1H, d, aromatic, J=6.80 Hz), 8.25 (1H, s, aromatic).
3-(2-(Benzofuran-2-yl)-2-hydroxyethyl)-6-methoxyquinazolin-4(3H)-one (9c)
White solid, yield: 64%, m.p.:89-91°C.FT-IR (KBr) ν (cm-1): 3341 (OH), 3075.71, 3061.41
& 2964.29 (C-H, aromatic& aliphatic), 1664.25 (C=O), 1629.11 (C=N), 1270.14 (C-O).1H
NMR (CDCl3) δ (ppm): 3.72 (3H, s, OCH3),4.32(2H, d, CH2, J=7.10 Hz),4.43(1H, t, CH,
J=7.10 Hz), 5.25(1H, brs, OH), 6.83 (1H, s, aromatic), 7.15-7.41 (5H, m, aromatic), 7.50
(1H, s, aromatic), 7.58 (1H, s, aromatic), 8.21 (1H, s, aromatic).
This article is protected by copyright. All rights reserved.

3-(2-(5-Bromobenzofuran-2-yl)-2-hydroxyethyl)quinazolin-4(3H)-one (9d)
White solid, yield: 73%, m.p.:108-109°C.FT-IR (KBr) ν (cm-1): 3352 (OH), 3102.61,
3068.71 & 2925.49 (C-H, aromatic & aliphatic), 1664.21 (C=O), 1611.55 (C=N), 1231.85
(C-O). 1H NMR (CDCl3) δ (ppm): 4.75 (2H, d, CH2, J=6.80 Hz), 4.86 (1H, t, CH, J=6.80
Hz), 5.31(1H, brs, OH), 7.51-7.72 (6H, m, aromatic), 7.98 (H, d, aromatic, J=7.10 Hz), 8.12
(1H, s, aromatic), 8.28 (1H, s, aromatic).
3-(2-(5-Bromobenzofuran-2-yl)-2-hydroxyethyl)-6-chloroquinazolin-4(3H)-one (9e)
White solid, yield: 68%, m.p.:108-110°C.FT-IR (KBr) ν (cm-1): 3370 (OH), 3110.07,
3084.41 & 2971.78 (C-H, aromatic & aliphatic), 1663.49 (C=O), 1610.62 (C=N), 1222.34
(C-O).1H NMR (CDCl3) δ (ppm): 4.96 (2H, d, CH2, J=7.00 Hz), 5.15 (1H, t, CH, J=7.00 Hz),
5.33(1H, brs, OH), 7.30 (2H, m, aromatic), 7.61 (2H, m, aromatic), 7.81 (1H, s, aromatic),
7.90 (1H, d, aromatic, J=6.90 Hz), 8.18, (1H, s, aromatic), 8.29 (1H, s, aromatic).
3-(2-(5-Bromobenzofuran-2-yl)-2-hydroxyethyl)-6-methoxyquinazolin-4(3H)-one (9f)
White solid, yield: 57%, m.p.:113-114°C.FT-IR (KBr) ν (cm-1): 3339 (OH), 3080.94,
3072.99 & 2871.29 (C-H, aromatic & aliphatic), 1659.04 (C=O), 1570.94 (C=N), 1259.34
(C-O).1H NMR (CDCl3) δ (ppm): 3.75 (3H, s, OMe), 4.89, (2H, d, CH2, J=7.50 Hz), 5.07
(1H, t, CH, J=7.50 Hz), 5.29(1H, brs, OH), 7.18-7.38 (4H, m, aromatic), 7.55 (1H, s,
aromatic), 7.78 (1H, s, aromatic), 8.00 (1H, s, aromatic), 8.12 (1H, s, aromatic).
3-(2-Hydroxy-2-(5-methoxybenzofuran-2-yl)ethyl)quinazolin-4(3H)-one (9g)
White solid, yield: 55%, m.p.:109-111°C.FT-IR (KBr) ν (cm-1): 3335 (OH), 3081.02,
3059.79 & 2897.43 (C-H, aromatic & aliphatic), 1660.04 (C=O), 1617.20 (C=N), 1286.04
(C-O).1H NMR (CDCl3) δ (ppm): 3.72 (3H, s, OMe), 4.32 (2H, d, CH2, J=7.40 Hz), 4.48
This article is protected by copyright. All rights reserved.

(1H, t, CH, J=7.40 Hz), 5.23 (1H, broad, OH), 6.80 (1H, s, aromatic), 6.93 (1H, s, aromatic),
6.95 (2H, m, aromatic), 7.51-7.60 (3H, m, aromatic), 8.00 (1H, d, aromatic, J=7.30 Hz), 8.18
(1H, s, aromatic).
6-Chloro-3-(2-hydroxy-2-(5-methoxybenzofuran-2-yl)ethyl)quinazolin-4(3H)-one (9h)
White solid, yield: 64%, m.p.:107-109°C.FT-IR (KBr) ν (cm-1): 3349 (OH), 3103.75,
3052.34 & 2902.96 (C-H, aromatic & aliphatic), 1665.98 (C=O), 1608.41 (C=N), 1284.05
(C-O).1H NMR (CDCl3) δ (ppm): 3.74 (3H, s, OMe),4.55 (2H, d, CH2, J=6.90 Hz), 4.78 (1H,
t, CH, J=6.90 Hz), 5.29(1H, brs, OH), 6.90 (1H, s, aromatic), 7.18-7.25 (2H, m, aromatic),
7.55-7.60 (2H, m, aromatic), 7.76 (1H, d, aromatic), 8.09 (1H, s, aromatic), 8.25 (1H, s,
aromatic).
3-(2-Hydroxy-2-(5-methoxybenzofuran-2-yl)ethyl)-6-methoxyquinazolin-4(3H)-one (9i)
White solid, yield: 60%, m.p.:103-105°C.FT-IR (KBr) ν (cm-1): 3363 (OH), 3051.14,
3039.49 & 2871.64 (C-H, aromatic & aliphatic), 1664.11 (C=O), 1626.04 (C=N), 1260.06
(C-O). 1H NMR (CDCl3) δ (ppm): 3.75 (3H, s, OMe), 3.79 (3H, s, OMe), 4.49 (2H, d, CH2,
J=7.60 Hz), 4.70 (1H, t, CH, J=7.60 Hz), 5.31 (1H, brs, OH), 6.91 (1H, s, aromatic), 7.12-
7.32 (3H, m, aromatic), 7.46 (1H, s, aromatic) 7.83 (1H, s, aromatic), 8.08 (1H, s, aromatic),
8.15 (1H, s, aromatic).
General procedure for the synthesis of 1-[[(1-(Benzofuran-2-yl)-2-(quinazolin-4(3H)-one-3-
yl)]ethyl-1-yl]-3- methyl imidazol-1-ium chloride derivatives (12a-i)
This article is protected by copyright. All rights reserved.

A solution of compounds 9a-i (5.0 mmol) in dichloromethane was treated with SOCl2 (5
mmol) at room temperature and the resulting solution was maintained at reflux temperature
for 6-8 h. After completion of the reaction as indicated by TLC, the solvent was evaporated
under reduced pressure and the residue was washed twice with n-hexane (10a-i). The
resulting residue was dissolved in acetonitrile and then a solution of methyl imidazole (11,
5.2 mmol) was added. The mixture was stirred at reflux temperature. After 36-48 h an
insoluble substance was formed this was filtered and washed with cold acetonitrile, then dried
to afford hybrid imidazolium salts (12a-i).
1-[[(1-(Benzofuran-2-yl)-2-(quinazolin-4(3H)-one-3-yl)]ethyl-1-yl]-3- methyl imidazol-1-ium
chloride (12a)
White solid, yield: 56%, m.p.:175-177°C.FT-IR (KBr) ν (cm-1): 3146.51, 3063.95 and
2837.92 (C-H, aromatic and aliphatic), 1664.90 (C=O), 1635.13 (C=N), 1248.97 (C-O).1H
NMR (CDCl3) δ (ppm): 2.71 (3H, s, CH3), 4.31 (2H, d, CH2, J=6.60 Hz), 4.70 (1H, t, CH,
J=6.60 Hz), 6.98 (1H, s, aromatic), 7.29-7.37 (4H, m, aromatic), 7.50-7.77 (5H, m, aromatic),
7.99 (1H, d, aromatic, J=7.20 Hz), 8.20 (1H, s, aromatic), 8.25 (1H, s, aromatic). Elemental
analysis: Calculated: 69.94, H: 4.71, N: 13.77, Found: C: 69.98, H: 4.78, N: 13.79.
1-[[(1- (Benzofuran-2-yl) -2-(6-chloro quinazolin-4(3H)-one-3-yl)] ethyl-1-yl] -3- methyl
imidazol-1-ium chloride (12b)
White solid, yield: 67%, m.p.:168-170°C. FT-IR (KBr) ν (cm-1): 3116.66, 3051.78 and
2893.25 (C-H, aromatic and aliphatic), 1667.83 (C=O), 1639.59 (C=N), 1283.92 (C-O).1H
NMR (CDCl3) δ (ppm): 2.83 (3H, s, CH3), 4.75 (2H, d, CH2, J=6.80 Hz), 5.01(1H, t, CH,
J=6.80 Hz), 6.97 (1H, s, aromatic), 7.25-7.35 (4H, m, aromatic), 7.52-7.57 (3H, m, aromatic),
7.93 (1H, s, aromatic), 8.10 (1H, s, aromatic), 8.19 (1H, s, aromatic), 8.25 (1H, s, aromatic).
This article is protected by copyright. All rights reserved.