Recyclable keggin heteropolyacids as an environmentally benign catalyst for the synthesis of new 2-benzoylamino-n-phenyl-benzamide derivatives under microwave irradiations at solvent-free conditions and the evaluation of biological activity

Article abstract of DOI:10.3390/molecules23010008

2-Benzoylamino-N-phenyl-benzamide derivatives (5a–h) were prepared from 2-phenyl-3,1-(4H)-benzoxazin-4-one 3 and substituted anilines 4a–h in the presence of a Keggin-type heteropolyacids series (H₃PW₁₂O₄₀·13H₂O

Full text of DOI:10.3390/molecules23010008

molecules
Article
Recyclable Keggin Heteropolyacids as an
Environmentally Benign Catalyst for the Synthesis of
New 2-Benzoylamino-N-phenyl-benzamide
Derivatives under Microwave Irradiations at
Solvent-Free Conditions and the Evaluation of
Biological Activity
1
,2
1,
3
Karima Ighilahriz-Boubchir , Baya Boutemeur-Kheddis *, Cherifa Rabia ,
Malika Makhloufi-Chebli 1 , Maamar Hamdi 1 and Artur M. S. Silva 4
,2
ID
1
Laboratoire de Chimie Organique Appliquée (Equipe Hétérocycles), Faculté de Chimie, Université des
Sciences et de la Technologie Houari Boumediène, BP 32, El-Alia, Bab-Ezzouar 16111, Algeria;
karima_ighil@yahoo.fr (K.I.-B.); makhloufi_malika@yahoo.fr (M.M.-C.); prhamdi@gmail.com (M.H.)
Laboratoire de Physique et Chimie des Matériaux (LPCM), Université Mouloud Mammeri, BP17RP,
Tizi Ouzou 15000, Algeria
Laboratoire de Chimie du Gaz Naturel, Faculté de Chimie, Université des Sciences et de la Technologie
Houari Boumediène, BP 32, El-Alia, Bab-Ezzouar 16111, Algeria; c_rabia@yahoo.fr
Department of Chemistry & QOPNA, University of Aveiro, 3810-193 Aveiro, Portugal; artur.silva@ua.pt
Correspondence:bayakheddis@hotmail.com; Tel./Fax: +213-21-24-73-11
2
3
4
*
Received: 19 November 2017; Accepted: 20 December 2017; Published: 21 December 2017
Abstract: 2-Benzoylamino-N-phenyl-benzamide derivatives (5a
4H)-benzoxazin-4-one and substituted anilines 4a in the presence of a Keggin-type heteropolyacids
series (H PW O 13H O; H SiW O 13H O; H SiMo O 13H O; and H PMo O 13H O)
–h) were prepared from 2-phenyl-3,1-
(
3
–h
·
·
·
·
3
12 40
2
4
12 40
2
4
12 40
2
3
12 40
2
as catalysts without solvent and under microwave irradiation. We found that the use of
H PW O 13H O acid coupled to microwave irradiation allowed obtaining a high-yielding
·
3
12 40
2
1
13
reaction with a short time. The compound structures were established by H-NMR and C-NMR.
The antibacterial and antifungal activities of the synthesized compounds exhibited an inhibition of
the growth of bacteria and fungi.
Keywords: Keggin-type heteropolyacids; 2-benzoylamino-N-phenyl-benzamide derivatives;
microwave irradiation; solvent free conditions; antibacterial; antifungal
1
. Introduction
The concept of the green chemistry consists in the development of an environmentally
friendly approach for organic synthesis using ecological and efficient protocols [
develop a methodology that could fit into the green chemistry field, for the synthesis of new
-benzoylamino-N-phenylbenzamide derivatives via benzoxazinone, the choice was made on the use
1]. In order to
2
of bothpolyoxometalates (POMs) as catalysts, known for their efficiency, and microwave irradiation
for time-saving.
Benzoxazinones can be used as precursor for the synthesis of wide variety of heterocyclic
compounds, such as quinazolinones and quinazolines [
already known for their biological and pharmacological activities [
antihypertensive [10], analgesic [11 12], anti-inflammatory [13],antimicrobial [14
andantibacterial [19] activities, antimuscular contractor and hypnotic activities [20], anti-fetal
2
–
4
]. The benzoxazinone derivatives are
], as anti-convulsants [ ],
16], antifungal [17 18
5
,6
7–9
,
,
–
]
Molecules 2018, 23, 8; doi:10.3390/molecules23010008
www.mdpi.com/journal/molecules

Molecules 2018, 23, 8
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activity [21], antidiabetic and hypolipidemic activity [22], and as antidepressants [23].
The benzoxazinones were also tested for their inhibitory activity toward human leukocyte elastase [24 25],
antimalarial, anticancer, and anti-HIV [26,27].
,
As benzoxazinones, the 2-benzoylamino-N-phenylbenzamide derivatives can be also used as
precursors for both quinazolinone and quinazoline synthesis, and can also present biological and
pharmacological activities.
The POMs, particularly the heteropolyacids (HPAs), having the Keggin structure, have received
much attention for organic synthesis. They are soluble in all the solvents, which allows for the recovery
of the synthesized product by simple filtration [28]. Thus, HPAs offer a strong option for efficient
and cleaner processes compared to polluting and corrosive liquid acid catalysts, such as mineral
acids. Effectively, in previous works, HPAs showed excellent catalytic activities in several reactions as
the synthesis of substituted 1,4-diazepines and 1,5-benzodiazepines [29], 4(3H)-quinazolinones [30],
calix [4] resorcinarenes [31], and 3,4-dihydropyrimidinones [32].
Among the derivatives of the 2-benzoylamino–N-phenylbenzamide (5a
N-phenylbenzamide 5a was synthesized from 2-phenyl-1,3-(4H)–benzoxazin-4-one
in the presence of HPAs series as formula H PW O (PW ), H SiW O (SiW ), H PMo O
12 40
–
h) series, 2-benzoylamino-
3
and aniline
3
12 40
12
4
12 40
12
3
(
PMo ) and H SiMo O (SiMo ), under microwave irradiation and solvent-free conditions. Then,
12 4 12 40 12
the most efficient catalyst was used to synthesize all the series of 2-benzoylamino-N-phenylbenzamide
derivatives via benzoxazinone 3, in the presence of substituted anilines (4a–h).
2
. Results and Discussion
In the literature, the synthesis of 2-phenyl-1,3-(4H)-benzoxazin-4-one
3
(Scheme 1) was carried
out from anthranilic acid 1 with benzoyl chloride via an intermediate 2 that cyclizes under the acetic
anhydride action, at reflux heating [33]. In this work, we took it back by using reflux heating and
microwave irradiation to highlight the efficiency of the latter. Thus, 97% of the product yield was
obtained in a few minutes under microwave irradiation against 90% after 2 h of the conventional reflux
heating method.
O
O
O
OH
Ph
OH
O
Ph-COCl
(CH CO) O
3 2
NH
NH
2
N
Ph
O
1
3
2
Scheme 1. Synthesis of 2-phenyl-1,3-(4H)-benzoxazin-4-one 3.
The 2-phenyl-1,3-(4H)-benzoxazin-4-one
N-phenylbenzamide 5a synthesis from its condensation with aniline
under microwave irradiation, in solvent-free conditions, using a series of Keggin-type heteropolyacids,
3
compound was used for the 2-benzoylamino-
4. The reaction was conducted,
HnXM O (abbreviated as XM , where X = P or Si and M = W or Mo) (Scheme 2). Results are
12
40
12
summarized in Table 1.
Table 1. 2-Benzoylamino-N-phenylbenzamide yields (%).
Catalysts
PW12
SiW12
PMo12
SiMo12
Yields (%)
80
72
65
56

Molecules 2018, 23, 8
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O
O
N
Ph
N
H
O
HPAs
Ph-NH
2
+
Microwave
NH
Ph
O
Ph
3
4
5a
Scheme 2. Synthesis of 2-benzoylamino-N-phenylbenzamide 5a by condensation of 2-phenyl-1,3-(4H)-
benzoxazin-4-one and aniline in the presence of HPAs under microwave irradiation in
solvent-free conditions.
3
4
2
-Benzoylamino-N-phenylbenzamide yields (Table 1) depended on the nature of both the metal
atom (W, Mo) and the heteroatom (P, Si) of HPA. Thus, W-based HPAs were more efficient than
Mo-based (72–80% against 56–65% of 5a yield). Phosphorus heteroatoms, which make the HPA more
active, unlike siliceous heteroatoms, resulted in a yield of 5a of 80% against 72% for W-based HPAs
and 65% against 56% for Mo-based HPAs. The results obtained show that the decrease in yield
(
PW12 > SiW12 > PMo12 > SiMo ) follows that of the acidity strength [34]. Thus, PW heteropolyacid
12 12
was chosenas the catalyst to synthesize a series of 2-benzoylamino-N-phenylbenzamide derivatives
with substituted anilines 4a in the same conditions (Scheme 3). The products are obtained in a
5
a
–
h
–h
few minutes. The results are summarized in Table 2.
O
O
Ar
N
H
O
PW12
Ar-NH
2
+
Microwave
NH
N
Ph
O
Ph
3
4a-h
5a-h
Scheme 3. 2-Benzoylamino-N-phenylbenzamide derivatives 5a
-phenyl-1,3-(4H)-benzoxazin-4-one with various substituted anilines 4a
catalyst under microwave irradiation in solvent-free conditions.
–
h
synthesis by condensation of
2
3
–h
in the presence of PW12
Table 2. Impact of aniline structure on reaction yield.
◦
◦
a
Products
ArNH (4a–h)
Yield (%)
M.p. ( C)
T ( C)
2
5
a
C H
4-Me-C H4
4-OH-C H
6 4
80
85
91
77
73
67
65
70
281–282
123–124
160–163
161–162
140–142
167–168
162–164
192–193
151
155
155
160
106
105
121
124
6
5
5
b
6
5
c
5
d
4-Cl-C H4
6
5
5
e
f
2,4-Cl -C H
2 6
3
3
3
3
2,5-Cl -C H
2 6
5
g
2,6-Cl -C H
2 6
5
h
3,4-Cl -C H
2 6
a
Temperature measurement by IR-thermometer.
The aniline substituent group nature shows a strong impact on the yields. Thus, the presence of
electron donating groups led to a yield increase. With methyl and hydroxy groups in C H , the yields
6
4
are 85% and 92%, respectively, against 80% for the phenyl. These groups are beneficial because of
their high electron density, induced by the aromatic system unlike, the electron withdrawing group as

Molecules 2018, 23, 8
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chloro, which led to a yield decrease from 80% to 78%. The presence of a second chlorine atom in the
aniline also led to a yield decrease from 78% to 65%. Among dichloroanilines, 2,4-dichloro-C H gave
6
3
the better yield (73% against 65–70%). This decrease is attributed to the group steric effect.
Scheme 4 shows a plausible mechanism of the 2-benzoylamino-N-phenylbenzamide 5a formation
in the heteropolyacid presence. The initial step corresponds to the protonation of carbonyl on a
Brønsted site of HPA favoring the amine attack that leads to the intermediate I1. Thelatter is then
deprotonated to give another intermediate I2 and the released proton is then recovered by the HPA.
Finally, a proton transfer from the aniline to the amide nitrogen takes place, thus leading to the final
product. It is known that the presence of an electron donating group favors the amine basic character.
(
HPA)
O
H
O
N
O
H
Ph
H
H
O
N
NPh
H
NHPh
O
O
-
H (HPA)
+
NH Ph
2
NH
N
Ph
N
Ph
O
Ph
O
Ph
3
I1
5a
4
a
I
2
Scheme 4. Proposed mechanism for the 2-benzoylamino-N-phenylbenzamide 5a formation.
3
. Antibacterial, Antifungal of the Synthesized Compounds
The synthesized compounds were screened for their antimicrobial activity against fungal and
bacterial pathogenic strains by the disc diffusion method [35 37]. Gram-negative bacterial strains,
–
namely Escherichia coli (ATCC-11105) and Pseudomonas aeruginosa (ATCC-9027), and Gram-positive
bacteria, namely Staphylococcus aureus (ATCC-6538) and Bacillus subtilis (ATCC-6633), were chosen as
model bacterial strains, and fungi, namely Candida albicans (ATCC-10231) and Aspergillus brasiliensis
ATCC-16404)). Agar plates, containing 2-benzoylamino-N-phenylbenzamide products dissolved in
dimethylsulfoxide (600
at 37 C for 24 h. Antimicrobial activity data are given in Table 3.
µ
g/mL) were inoculated uniformly from fresh bacterial culture and incubated
◦
Table 3. Antimicrobial activity data of the synthesized compounds 5a
–
h, determined by the agar
diffusion method.
Bacteria
Fungi
Compounds
E. coli
S. aureus
P. aeruginosa
B. subtilis
C. albicans
A. brasiliensis
5
a
++
+
-
+
++
+++
+++
+
+++
++
++
++
+++
++
+
++
++
+++
+++
-
+++
+++
+++
+++
+++
+++
+++
+++
+++
+++
+++
+++
+++
+++
+++
+++
5
b
5
c
++
++
++
++
++
++
5
5
d
e
5
f
5
g
++
+
++
++
++
++
5
h
The sensitivity of microorganisms, toward tested compounds, was identified in the following manner: no activity
- ≤ 8 mm), slightly active (8 < + < 16 mm), moderately active (16 ++ 20 mm) and highly active (+++ > 20 mm).
(
≤
≤
Antibacterial screening revealed that all tested compounds 5a–h showed from moderate (++)
to good (+++) inhibition against bacterial strains: E. coli, P. aeruginosa. For S. aureus and B. subtilis
bacterial strains, 5a and 5f, respectively, do not show any antibacterial activity. Antifungal screening
also revealed that all the tested compounds 5a–h showed a good (+++) inhibition against C. albicans
and A. brasiliensis.

Molecules 2018, 23, 8
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The antibacterial and antifungal activities of a compound capable of inhibiting the visible growth
of bacterial and fungal strains are defined by the value of the MIC that corresponds to its lower
concentration. In order to determine the minimum inhibition concentration (MIC) values of the
compound 5e against the bacterial strains mentioned above, it was dissolved in DMSO at different
concentrations (100, 200, 300, 400 and 600
µg/mL). The results are summarized in Table 4. The MIC
values found for compound 5e are less than 100
µg/mL for E. coli, P. aeruginosa, B. subtilis, and
C. albicans, and they are 100–200 and 300–400 µg/mL for S. aureus and A. brasiliensis, respectively.
Table 4. Minimum inhibitory concentration (MIC) values of compound 5e.
Bacteria
P. aeruginosa
Fungi
A. brasiliensis
Concentration
µg/mL)
(
E. coli
S. aureus
B. subtilis
C. albicans
6
4
3
2
1
00
00
00
00
00
++
+
+
+
+
+
+
+
+
+
+
+
+
+
++
++
+
+
+
+++
+++
+++
++
+++
+
-
-
-
++
-
MIC
≤100
100–200
≤100
≤100
≤100
300–400
The sensitivity of microorganisms, toward tested compounds, was identified in the following manner: no activity
(
- ≤ 8 mm), slightly active (8 < + < 16 mm), moderately active (16
≤
++
≤
20 mm), and highly active (+++ > 20 mm).
4
. Conclusions
High 2-benzoylamino-N-phenylbenzamides derivatives 5a
–h yields (66–92%) with short reaction
times (3 min) were obtained using a microwave irradiation and Keggin-type heteropolyacids as
catalysts in solvent free conditions. A plausible mechanism of the 2-benzoylamino-N-phenylbenzamide
5a formation was proposed. 2-Benzoylamino-N-phenyl benzamides derivatives 5a–h showed both
moderate and good antibacterial and antifungal activities. These results give an idea of further research
on these molecules in the biological domain.
5
. Experimental Section
5
.1. General
n
12 40 12
Pure heteropolyacids H XM O (PM ) were prepared by the standard method involving
the synthesis of the corresponding sodium salt and the extraction of acid by diethyl ether and its
◦
purification by crystallization in water at 4 C [38].
All research chemicals and solvents were purchased from Sigma-Aldrich (Sigma-Aldrich,
Saint-Quentin-Fallavier, France) and were used as such for the reactions. The progress of all the
reactions was monitored by thin-layer chromatography (TLC) using glass plates precoated with silica
gel-60 F254 to a thickness of 0.5 mm. The melting points were taken in an open capillary tube using
an Electrothermal melting point apparatus (Electrotermal, Rochford, Great Britain). The values are
◦
1
reported in C and are uncorrected. NMR spectra were recorded with a Bruker Avance 300 spectrometer
(
13
300 MHz ( H) and 75 MHz ( C)) (Bruker Biospin GmbH, Rheinstetten, Germany). Chemical shifts
are expressed in parts per million (ppm) downfield from using tetramethylsilane (TMS). Data are
reported as follows: chemical shift (multiplicity (s: singlet, d: doublet, dd: double doublet, ddd:
double double doublet, dm: double multiplet, dt: double triplet, t: triplet, td triple doublet, tm, triple
multiplet, tt: triple triplet, q: quartet, quint: quintuplet, m: multiplet, br: broad), coupling constants
(
J) in Hertz, integration). All the compounds gave satisfactory elemental analysis within
±
0.4% of
theoretical values.
The multimode microwave reactor (a modified Candy MGA 20 M microwave oven) has a single
magnetron (2450 MHz) with a maximum delivered power of 800 W. Experiments were carried out
in a Pyrex reactor fitted with a condenser. During experiments, the temperature was monitored with
an external infrared thermometer, Flashpoint FZ400 (Shenzhen Jumaoyuan Science and Technology

Molecules 2018, 23, 8
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CO., LTD, Guangdong, China). Our modifications to a domestic microwave oven, adopted since 1992,
are similar to those described, currently, for microwave chemistry experiments [39]. In a typical design,
a hole was drilled for a condenser tube in the oven top. External steel tube of the same diameter
(
~12 cm long) was welded to the hole in order to eliminate possible microwave leakage. The microwave
equipment operates within the safety limits prescribed: the accepted limit on the safe stray leakage of
2
the microwave power density is 10 mW/cm at 2450 MHz measured at a 50 mm distance from the
equipment (microwave leakage detector). The apparatus has been adapted for laboratory applications
with an external reflux condenser, multi-limb vacuum receivers, and a Dean Stark trap.
5
.2. General Procedure for the Preparation of 2-Phenyl-3,1-(4H)-benzoxazin-4-one 3
Method I (conventional heating): A mixture of anthranilic acid (10 mmol) and benzoyl chloride
(
10 mmol) was carried out under reflux in toluene (15 mL) for 2 h. A white solid wasobtained. The latter
wasthen treated with the acetic anhydride under reflux for 2 h.
Method II (microwave irradiation): A mixture of anthranilic acid (10 mmol) and benzoyl chloride
(10 mmol) and 10 mL of toluene was carried out under microwave irradiation. The power was
initially set to 420 W for 5 min, and then it was increased to 510 W for 7 min. A white solid
wasobtained. The latter with the acetic anhydride (10 mL) irradiated under microwave at 500 W
for 8 min. The obtained solid was washed by the water to eliminate acid.
◦
3). White solid, Yield 97%; m.p. 126 C; H-NMR (CDCl ,
3
1
2
3
-Phenyl-3,1-(4H)-benzoxazin-4-one (
00 MHz): = 7.24–8.35 (m, 9H, Ar-H) ppm; C-NMR (CDCl , 75 MHz):
13
δ
δ = 116.62, 126.80, 127.73,
3
1
28.02, 128.26, 129.81, 132.13, 135.96, 146.46, 156.52, 158.80 ppm; Anal. Calcd. for C H NO : C, 75.58;
14 9 2
H, 4.12; N, 6.28;O, 14.00. Found: C, 75.33; H, 4.06; N, 6.27; O, 14.33%.
5
.3. General Procedure for the Preparation of 2-Benzoylamino-N-phenylbenzamide Derivatives 5a–h
To a mixture of 2-phenyl-3,1-(4H)-benzoxazin-4-one (10 mmol) and amines (10 mmol) was
added the catalyst heteropolyacid (1.2 mol %). This mixture was heated by microwave, initially
set to 300 W for 3 min and then it was increased to 450 W for 10 min. The obtained solid was
1
13
washed by the water to eliminate acid. The H-NMR and C-NMR spectrums of compounds 5a–h in
Supplementary Materials.
◦
-Benzoylamino-N-phenylbenzamide (5a): Yield 80%; m.p. 281 C; H-NMR (DMSO-d , 300.13 MHz):
6
1
2
δ = 11.68 (s, 1H, NH), 10.55 (s, 1H, NH), 8.47 (d, J = 8.6 Hz, 1H), 7.92 (d, J = 8.1 Hz, 3H), 7.72 (d,
J = 7.56 Hz, 2H), 7.65–7.69 (m, 4H), 7.30–7.40 (m, 3H), 7.16(t, J = 7.02 Hz, 1H); 13C-NMR (DMSO-d6,
75.47MHz):
δ = 166.90, 166.85, 138.16, 137.98, 133.97, 133.90, 131.77, 131.56, 128.44, 128.18, 126.52,
1
22.82, 120.67 ppm. Anal. Calcd. for C H N O : C, 76.13; H, 5.25; N, 8.98; O, 9.63. Found: C, 75.93;
20
16
2
2
H, 5.10; N, 8.86; O, 10.11%.
◦
1
2
3
3
-Benzoylamino-N-(4-methylphenyl)benzamide (5b): Yield 85%; m.p. 123 C; H-NMR (DMSO-d ,
6
00.13 MHz):
δ
= 11.81 (s, 1H, NH), 10.49 (s, 1H, NH), 8.63 (d, J = 8.3Hz, 1H), 8.54 (d, J = 9 Hz,
13
H), 7.61–7.32 (m, 6H), 7.10–7.20 (m, 3H), 2.29 (s, 3H); C-NMR (DMSO-d , 75.47 MHz):
δ
= 167.80,
6
165.00, 139.31, 136.34, 133.88, 132.50, 131.77, 129.62, 129.38, 128.04, 127.46, 123.65, 121.67, 121.56,
2
1.10 ppm. Calcd. for C H N O : C, 76.55; H, 5.60; N, 8.53; O, 9.31. Found: C, 76.43; H, 5.49; N, 8.48;
21 18 2 2
O, 9.69%.
◦
1
2
-Benzoylamino-N-(4-hydroxyphenyl)benzamide (5c): Yield 92%; m.p. 160 C; H-NMR (DMSO-d ,
6
300.13 MHz):
δ
= 11.99 (s, 1H, NH), 10.37 (s, 1H, NH), 9.38 (s, 1H), 8.57 (d, J = 8.4 Hz, 1H), 8.23
(
1
d, J = 8.4 Hz, 1H), 7.65 (dd, J = 8.4 Hz, 4H), 7.63–7.47 (m,4H), 7.47 (d, J = 8.4 Hz, 2H), 7.16 (d, J = 6 Hz,
13
H); C-NMR (DMSO-d , 75.47 MHz):
δ
= 166.90, 166.85, 152.16, 137.98, 133.97, 133.90, 131.77, 131.56,
6
1
27.54, 127.28, 125.52, 121.82, 120.67 ppm. Calcd. for C H N O : C, 72.50; H, 4.96; N, 8.49; O, 14.04.
20
16
2
3
Found: C, 72.28; H, 4.85; N, 8.43; O, 14.44%.

Molecules 2018, 23, 8
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◦
-Benzoylamino-N-(4-chlorophenyl)benzamide (5d): Yield 78%; m.p. 161 C; H-NMR (DMSO-d ,
6
1
2
3
7
00.13 MHz): δ = 11.56 (s, 1H, NH), 10.66 (s, 1H, NH), 8.44 (d, J = 8.2 Hz, 1H), 7.92 (d, J = 7.1 Hz, 3H),
.74 (d, J = 8.6 Hz, 2H), 7.65–7.57 (m, 4H), 7.42 (d, J = 9.1 Hz, 2H), 7.26 (t, J = 9.1 Hz, 1H); 13C-NMR
(
DMSO-d , 75.47 MHz):
δ
= 167.48, 164.69, 138.62, 137.57, 134.50,132.35, 132.05, 129.05, 128.89, 128.60,
6
1
27.95, 127.09, 123.37, 122.97, 122.59, 121.52 ppm. Calcd. for C H ClN O : C, 68.55; H, 4.36; N,10.13;
20
15
2
2
O, 16.95. Found: C, 68.48; H, 4.31; Cl, 10.11; N, 7.99; O, 9.12%.
◦
-Benzoylamino-N-(2,4-dichlorophenyl)benzamide (5e): Yield 73%; m.p. 140 C; H-NMR (DMSO-d ,
6
1
2
3
3
00.13 MHz):
δ = 11.93 (s, 1H, NH),10.49 (s, 1H, NH), 8.58 (d, J = 8.6 Hz, 1H), 8.04 (d, J = 6.75 Hz,
13
H), 7.72 (s, 1H), 7.65–7.49 (m, 6H), 7.43 (t, J = 8.1 Hz, 1H) ppm. C-NMR (DMSO-d , 75.47 MHz):
6
δ = 164.10, 157.65, 147.39, 136.47, 134.90, 134.10, 132.13, 131.98, 131.18, 130.51, 129.16, 127.53, 127.43,
127.40, 127.03, 125.86, 125.68, 120.22 ppm. Calcd. for C H Cl N O : C, 62.50; H, 3.71; Cl, 18.48; N,
20 14 2 2 2
7
.37; O, 7.94 Found: C, 62.34; H, 3.66; Cl, 18.41; N, 7.27; O, 8.31%.
◦
1
2
3
2
-Benzoylamino-N-(2,5-dichlorophenyl)benzamide (5f): Yield 68%; m.p. 167 C; H-NMR (DMSO-d ,
6
00.13 MHz):
H), 7.73 (s, 1H), 7.67 (d, J = 7.29 Hz, 1H), 7.61–7.40 (m, 7H), 7.41 (t, J = 8.1 Hz, 1H) ppm, C-NMR
= 167.98, 165.30, 139.21, 138.77, 134.90, 132.81, 132.45, 131.35, 130.96, 129.72,
29.41, 127.55, 126.15, 123.98, 123.90, 122.53, 122.34, 121.90 ppm. Calcd. For C H Cl N O : C, 62.50;
δ = 11.75 (s, 1H, NH), 10.45 (s, 1H, NH), 8.49 (d, J = 8.4 Hz, 1H), 7.91 (d, J = 8.0 Hz,
13
(
DMSO-d , 75.47 MHz): δ
6
1
20
14
2
2
2
H, 3.71; Cl, 18.48; N, 7.37; O, 7.94 Found: C, 62.34; H, 3.66; Cl, 18.41; N, 7.27; O, 8.31%.
◦
1
2
3
7
-Benzoylamino-N-(2,6-dichlorophenyl)benzamide (5g): Yield 65%; m.p. 162 C; H-NMR (DMSO-d ,
6
00.13 MHz): δ = 12.08 (s, 1H, NH), 10.75 (s, 1H, NH), 8.70 (d, J = 8.2 Hz, 1H), 8.11 (d, J = 6.9 Hz, 2H),
.87 (d, J = 6.9 Hz, 1H), 7.62–7.50 (m, 5H), 7.45 (d, J = 6.9 Hz, 2H), 7.32 (t, J = 8.1 Hz, 1H) ppm; 13C-NMR
(
DMSO-d , 75.47 MHz):
δ
= 168.38, 165.00, 140.11, 134.74, 134.52, 133.67, 132.90,132.63, 130.32, 129.47,
6
1
7
29.15, 127.32, 123.66, 121.18, 119.97 ppm. Calcd. for C H Cl N O : C, 62.50; H, 3.71; Cl, 18.48; N,
.37; O, 7.94 Found: C, 62.34; H, 3.66; Cl, 18.41; N, 7.27; O, 8.31%.
20
14
2
2
2
◦
1
2
-Benzoylamino-N-(3,4-dichlorophenyl)benzamide (5h): Yield 70%; m.p. 192 C; H-NMR (DMSO-d ,
6
3
00.13 MHz): δ = 11.36 (s, 1H, NH), 10.71 (s, 1H, NH), 8.34 (d, J = 7.29 Hz, 1H), 8.01 (s, 1H), 7.92–7.85
13
(
m, 3H), 7.70–7.31 (m, 5H), 7.28 (t, J = 6.75Hz, 1H) ppm; C-NMR (DMSO-d , 75.47 MHz):
δ
= 167.98,
6
1
1
6
65.30, 139.23, 138.77, 134.90, 132.81, 132.45, 131.35, 130.96, 129.41, 129.27, 126.15, 123.99, 123.91, 122.54,
22.35, 121.30 ppm. Calcd. for C H Cl N O : C, 62.50; H, 3.71; Cl, 18.48; N, 7.37; O, 7.94 Found: C,
20
14
2
2
2
2.34; H, 3.66;Cl, 18.41; N, 7.27; O, 8.31%.
5.4. Screening for Antibacterial Activity by the Agar Diffusion Method for
2-Benzoylamino-N-phenylbenzamide Derivatives 5a–h
The antimicrobial activities of compounds 5a–h were evaluated for their antibacterial activities
against S. aureus (ATCC29213), B. subtilis (ATCC6633), E. coli (ATCC11105)), P. aeruginosa (ATCC9027),
and Bacillus subtilis (ATCC-6633) bacterial strains and their anti-fungal activities against C. albicans
(ATCC-10231) and A. brasiliensis (ATCC-16404) by the agar diffusion method [37]. A sterile
physiological water solution contained a bacterial colonies, was prepared at room temperature,
6
with an optical density of 0.08–0.10 corresponding to a concentration of 10 cells/mL. The bacterial
solution was inoculated in the Muller-Hinton agar medium by swabbing using Petri dishes at room
temperature. The tested compounds were dissolved in dimethylsulfoxide (DMSO) with a concentration
of 600 µg/mL. Twenty-five microlliters of tested sample were poured onto filter paper discs 6 mm
in diameter, which were then delicately placed on the surface of the agar plates. These were later
◦
maintained at 37 C for 24 h. Activities were determined by measuring the diameter of the inhibition
zone (mm).

Molecules 2018, 23, 8
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5
.5. Minimum Inhibitory Concentration Determination of the Compound 5e
In order to determine the minimum inhibition concentration (MIC) values of the compound 5e
different concentrations (100, 200, 300, 400 and 600 g/mL)were considered. The MIC of the sample
,
µ
showedno turbidity and was recorded as the lowest concentration of the compound that would
completely inhibit bacterial growth. Each test was performed in triplicate.
Supplementary Materials: The H-NMR and 13C-NMR spectrums of compounds 5a–h are available online.
1
Acknowledgments: Thanks are due to the University of Aveiro, Portugal for the spectroscopic analysis. This work
was supported by the Ministry of Higher Education and Scientific Research (Algeria).
Author Contributions: Baya Boutemeur-Kheddis andKarimaIghilahriz-Boubchir conceived, designed;
all experiments and analysis were carried out by Karima Ighilahriz-Boubchir; Baya Boutemeur-Kheddis,
Karima Ighilahriz-Boubchir, and Maamar Hamdi discussed the NMR data; Artur M.S. Silva and
Malika Makhloufi-Chebli contributed the analysis tools; and Baya Boutemeur-Kheddis and Cherifa Rabia provided
conceptual guidance, supervised the project, and edited the manuscript.
Conflicts of Interest: The authors declare no conflict of interest.
References
1.
2.
3.
4.
Sarma, R.; Prajapati, D.; Boruah, R.C. Green chemistry-A new approach in organic synthesis. Sci. Cult. 2011
,
7
7, 461–465.
Maher, A.E.; Khalid, M.D.; Sameh, A.R.; Fakhry, A.E. The Uses of 2-Ethoxy-(4H)-3,1-benzoxazin-4-onein the
Synthesis of Some Quinazolinone Derivatives of Antimicrobial Activity. Pharmaceuticals 2011, 4, 1032–1051.
Saurav, K.; Garima, M.; Pradeep, S.; Jha, K.; Khosa, R.; Gupta, S. Quinazoline-4-one: A highly important the
heterocycle with diverse biological activities. Der Chem. Sin. 2011, 2, 36–58.
Parkanyi, C.; Yuan, H.L.; Stromberg, B.H.E.; Evenzahav, A. Synthesis of 5-fluoro-2 -methyl- 3-(2-trifluoro
methyl-1,3,4-thiadiazol-5-yl)-4(3H)-quinazolinone and related compounds with potential antiviral and
anticancer activities. J. Heterocycl. Chem. 1992, 29, 749–753. [CrossRef]
5
.
Abbas, E.S.; Awadallah, M.F.; Ibrahim, A.N.; Said, G.E.; Kamel, M.G. New quinazolinone-pyrimidine hydrids:
Synthesis, anti-inflammatory and ulceronicity studies. Eur. J. Med. Chem. 2012, 53, 141–149. [CrossRef]
[PubMed]
6
7
8
.
.
.
Sicker, D.; Schulz, M. Benzoxazinones in plants: Occurrence, synthetic access, and biological activity.
In Studies of Natural Product Chemistry; Atta-ur, R., Ed.; Elsevier: Amsterdam, The Netherlands, 2002.
Erusalimsky, J.D.; Franklin, R. Is the platelet lowering activity of anagrelide mediated by its major metabolit
2
-amino-5,6-dichloro-3,4-dihydroquinazoline (RL603)? Exp. Hematol. 2002, 30, 625–626. [CrossRef]
Farghaly, A.M.; Soliman, R.; Khalil, M.A.; Bekhit, A.A.; El-Din, A. Hioglycolic acid and pyrazole derivatives
of 4(3H)-quinazolinone: Synthesis and antimicrobial evaluation. Boll. Chim. Farm. 2002, 141, 372–378.
[PubMed]
9
.
Blackburn, C.; Lamorche, M.J.; Brown, J. Identification and characterization of amino piperidinequinolones
and quinazolinones as MCHr 1antagonists. Bioorg. Med. Chem. Lett. 2006, 16, 2621–2627. [CrossRef]
[
PubMed]
0. Sayed, H.M.; Hamed, A.A.; Madkour, H.M.F.; Shiba, S.A. Utility of 3-(4-Methoxy phenyl) and/or
2-Thinyl)-2-cyano-2-propenoyl chloride in heterocyclic synthesis. Sulfur Lett. 2001, 24, 151–179.
1. Al-Obaid, A.M.; Abdel-Hamide, S.G.; El-Kashef, H.A.; Abdel-Aziz, A.M.; El-Azab, A.S. Substituted
quinazolines, Part 3. Synthesis, in vitro antitumor activity and molecular modeling study of certain
1
1
(
2
-thieno-4(3H)-quinazolinone analogs. Eur. J. Med. Chem. 2009, 44, 2379–2391. [CrossRef] [PubMed]
2. Aly, M.M.; Mohamed, Y.A.; El–Bayouki, K.A.M.; Basyaouni, W.M.; Abbas, S.Y. Synthesis of some
(3H)-quinazolinone-2-carboxaldehyde thiosemicarbazones and their metal complexes and a study on
their anticonvulsant, analgesic, cytoxic and antimicrobial activities Part-1. Eur. J. Med. Chem. 2010, 45,
365–3373. [CrossRef] [PubMed]
3. Chandrika, P.M.; Yakaiah, T.; Ramrao, A.R.; Rao, J.V. Synthesis of novel 4,6-disubstituted quinazoline
derivatives, their anti-inflammatory and anti-cancer activity (cytotoxic) against U937 leukemia cell lines.
Eur. J. Med. Chem. 2008, 43, 846–852. [CrossRef] [PubMed]
1
1
4
3

Molecules 2018, 23, 8
9 of 10
1
4. Mathew, B.P.; Kumar, A.; Sharma, S.; Shukla, P.K.; Nath, M. Aneco-friendly synthesis and antimicrobial
activities of dihydro-2H-benzo-and naphtho-1,3-oxazine derivatives. Eur. J. Med. Chem. 2010, 45, 1502–1507.
CrossRef] [PubMed]
[
1
1
1
1
1
2
2
5. Zulfiqar, A.K.; Sayd, A.R.N.; Sohail, A.S.; Nasir, M.; Muhammad, Y.; Ameer, F.Z. Synthesis and Antimicrobial
Activity of 2-Aryl-4H-3,1-benzoxazin-4-ones. Asian. J. Chem. 2013, 25, 152–156.
6. Kaniskan, N.; Kokten, S.; Celik, I. A new protocol for the synthesis of primary, secondary and tertiary
anthranilamides utilizing N-(2-aminoarylacyl)benzotriazoles. Arkivok 2012, 8, 198–213.
7. Alyaa, A.S.; Abdel Momen, A.E.; Shiba, S.A.; Abdel, A.A.E. Synthesis and antifungal activity of some new
quinazoline and benzoxazinone derivatives. Arch. Pharm. Med. Chem. 2000, 333, 365–372.
8. Héctor, R.B.; Waldo, L. Antialga and Antifungal Activity of Natural Hydroxamic Acids and Related
Compounds. J. Agric. Food Chem. 1996, 44, 1569–1571.
9. Héctor, R.B.; Sylvia, V.C.; Waldo, L. Antimicrobial activity of natural 2-benzoxazolinones and related
derivatives. J. Agric. Food Chem. 1997, 45, 3255–3257.
0. Arfan, M.; Khan, R.; Imran, M.; Khan, H.; Mehmood, J. One-pot synthesis and antimicrobial activities of
some 2-aryl/alkyl, 3-aminoquinazolin-4(3H)-ones. J. Chem. Soc. Pak. 2008, 30, 229–305.
1. Hsieh, P.; Chong, F.; Chang, C.; Zheng, F.; Lin, K.H. 2-Substituted benzoxazinone analogues as anti-human
Corona virus (anti-HcoV) and ICAM-1 expression inhibition agents. Bioorg. Med. Chem. Lett. 2004, 14,
4
751–4754. [CrossRef] [PubMed]
2. Madhavan, G.R.; Chakrabarti, R.; Reddy, K.A.; Rajesh, B.M.; Rao, P.B.; Rajagopalan, R.; Iqbal, J. Dual PPAR-
and - activators derived from novel benzoxazinone containing thiazolidinediones having antidiabetic and
hypolipidemic potential. Bioorg. Med. Chem. 2006, 14, 584–591. [CrossRef] [PubMed]
3. Nachiket, S.D.; Pankaj, S.S.; Ravindra, B.L.; Santosh, B.D.; Deepak, S.M. Design, synthesis and evaluation of
acute toxicity studies and anti-depressant activities of some new derivatives of 1,3-benzoxazin-4-one. Int. J.
Pharm. Chem. 2015, 5, 158–165.
2
2
2
2
α
γ
4. Colson, E.; Wallach, J.; Hauteville, M. Biochimie, Synthesis and anti-elastase properties of
6
2
-amino-2-phenyl-4H-3,1-benzoxazin-4-one aminoacyl and dipeptidyl derivatives. Biochimie 2005, 87,
23–230. [CrossRef] [PubMed]
5. Pei-Wen, H.; Tsong-Long, H.; Chin-Chung, W.; Fang-Rong, C.; Tsai-Wei, W.; Yang-Chang, W. The evaluation
of 2,8-disubstituted benzoxazinone derivatives as anti-inflammatory and anti-platelet aggregation agents.
Bioorg. Med. Chem. Lett. 2005, 15, 2786–2789.
2
2
2
2
6. Habib, O.M. O.; Hassan, H.M.; El-Mekabaty, A. Novel quinazolinone derivatives: Synthesis and
anti-microbial activity. Med. Chem. Res. 2013, 22, 507–519. [CrossRef]
7. Habib, O.M.O.; Hassan, H.M.; El-Mekabaty, A. Studies on Some Benzoxazine-4-one Derivatives with
Potential Biological Activity. Am. J. Org. Chem. 2012, 2, 45–51. [CrossRef]
8. Misono, M. Heterogeneous Catalysis by Heteropoly Compounds of Molybdenum and Tungsten. Catal. Rev.
1
987, 29, 269–321. [CrossRef]
9. Kaoua, R.; Bennamane, N.; Bakhta, S.; Benadji, S.; Rabia, C.; Nedjar-Kolli, B. Synthesis of substituted
,4-diazepines and 1,5-benzodiazepines using an efficient heteropolyacid-catalyzed procedure. Molecules
011, 16, 92–99. [CrossRef] [PubMed]
1
2
3
0. Ighilahriz, K.; Boutemeur, B.; Chami, F.; Rabia, C.; Hamdi, M.; Hamdi, S.M. A microwave-assisted and
heteropolyacids-catalysed cyclocondensation reaction for the synthesis of 4(3H)-quinazolinones. Molecules
2
008, 13, 779–789. [CrossRef] [PubMed]
3
1. Hedidi, M.; Hamdi, S.M.; Mazari, T.; Boutemeur, B.; Rabia, C.; Chemat, F.; Hamdi, M. Microwave-assisted
synthesis of calix [4] resorcinarenes. Tetrahedron 2006, 62, 5652–5655. [CrossRef]
3
2. Saher, L.; Makhloufi-Chebli, M.; Dermeche, L.; Boutemeur-Khedis, B.; Rabia, C.; Silva, A.M.S.;
Hamdi, M. Keggin and dawson-type polyoxometalates and efficient catalysts for the synthesis
3,4-dihydropyrimidinones: Experimental and theoretical studies. Tetrahedron Lett. 2016, 57, 1492–1496.
[CrossRef]
3
3
3. Shariat, M.; Samsudin, M.W.; Zakaria, Z. One-pot synthesis of 2-substituted 4H-3,1-benzoxazin-4-one
derivatives under mild conditions using iminium cation from cyanuric chloride/dimethylformamide as a
cyclizing agent. Chem. Cent. J. 2013, 1–6, 7–58. [CrossRef] [PubMed]
4. Timofeeva, M.N. Acid catalysis by heteropoly acids. Appl. Catal. A 2003, 256, 19–35. [CrossRef]

Molecules 2018, 23, 8
10 of 10
3
3
3
3
3
5. Doley, P.; Jha, D.K. Antimicrobial activity of bacterial endophytes from medicinal endemic plant Garcinia
Lancifolia Roxb. Ann. Plant Sci. 2016, 4, 1243–1247.
6. Jorgensen, J.H.; Turnidge, J.D. Susceptibility test methods: Dilution and disk diffusion methods. In Manual
of Clinical Microbiology; ASM Press: Washington, DC, USA, 2015.
7. Nascimento, G.G.F.; Locatelli, J.; Freitas, P.C.; Silva, G.L. Antibacterial activity of plant extracts and
phytochemicals on antibiotic- resistant bacteria. Br. J. Microbiol. 2000, 31, 247–256. [CrossRef]
8. Pope, M.T. Heteropoly and isopolyoxometallates. In Inorganic Chemistry Concepts; Springer: Berlin/Heidelberg,
Germany, 1983.
9. Nüchter, M.; Ondruschka, B.; Bonrath, W.; Gum, A. Microwave assisted synthesis—A critical technology
overview. Green Chem. 2004, 6, 128–141. [CrossRef]
Sample Availability: Samples of the compounds 5a–h are available from the authors.
©
2017 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access
article distributed under the terms and conditions of the Creative Commons Attribution
(CC BY) license (http://creativecommons.org/licenses/by/4.0/).