Heterocyclic synthesis: A convenient route to some 2-mercepto 1,3,4-oxadiazole and green chemistry microwave-induced one-pot synthesis of 2-aryl 1,3,4-oxadiazole in quinazolone and their antibacterial and antifungal activity

Article abstract of DOI:10.1002/jhet.5570420539

Several 6-substituted-3-[(5-mercepto-1,3,4-oxadiazol-2-yl)methyl]-2- substituted quinazolin-4(3H)-one or 6-substituted-3-[4-(5-mercepto-1,3,4- oxadiazol-2-yl)phenyl]-2-substituedquinazolin-4(3H)-one 2(a-l) and 6-substituted-3-[(5-phenyl-1,3,4-oxadiazol-2-yl)methyl]-2-substitutedquinazolin- 4(3H)-one or 6-substituted-3-[4-(5-phenyl-1,3,4-oxadiazol-2-yl) phenyl]-2-substitutedquinazolin-4(3H)-one 3(a-l) were synthesized using conventional and microwave techniques respectively and were screened for antibacterial and antifungal activity.

Full text of DOI:10.1002/jhet.5570420539

Heterocyclic Synthesis: A Convenient Route to Some 2-Mercepto 1,3,4-
Oxadiazole and Green Chemistry Microwave-Induced One-Pot
Synthesis of 2-Aryl 1,3,4-Oxadiazole in Quinazolone and Their
Antibacterial and Antifungal Activity
Jul-Aug 2005
995
1
1*
A. R. Desai and K. R. Desai
1
Department of Chemistry, Veer Narmad South Gujarat University,
Surat-395007 (Gujarat), India
Ph: - +91-0261-2256012, Fax: - +91-261-2256012
Email: - k_r_desai@rediffmail.com, amardesai1978@yahoo.com
Received November 29, 2004
Several 6-substituted-3-[(5-mercepto-1,3,4-oxadiazol-2-yl)methyl]-2-substituted quinazolin-4(3H)-one
or 6-substituted-3-[4-(5-mercepto-1,3,4-oxadiazol-2-yl)phenyl]-2-substituedquinazolin-4(3H)-one 2(a-l)
and 6-substituted-3-[(5-phenyl-1,3,4-oxadiazol-2-yl)methyl]-2-substitutedquinazolin-4(3H)-one or 6-substi-
tuted-3-[4-(5-phenyl-1,3,4-oxadiazol-2-yl) phenyl]-2-substitutedquinazolin-4(3H)-one 3(a-l) were synthe-
sized using conventional and microwave techniques respectively and were screened for antibacterial and
antifungal activity.
J. Heterocyclic Chem., 42, 995 (2005).
Introduction.
mercepto-1,3,4-oxadiazol-2-yl)methyl]-2-substitut-
edquinazolin-4(3H)-one or 6-substituted-3-[4-(5-mercepto-
The increasing environmental consciousness throughout
the world has put a pressing need to develop an alternate
synthetic approach for biologically and synthetically
important compounds. The present day industrialization
has led to immense environmental deterioration. One of
the advances in the field of green chemistry [1] where sub-
stantial progress has been made is the microwave-assisted
solid-supported one-pot synthesis [2]. Inorganic solid sup-
ports (aluminas, silicas, zeolites, clays) coupled with
microwaves have made a landmark in this direction as
reactions can be performed in dry media or under solvent-
less conditions [3].
Scheme 1
Substituted 1,3,4-oxadiazoles are of considerable phar-
maceutical and material interest, which is documented by a
steadily increasing number of publications and patents. For
instance, 2-amino-1,3,4-oxadiazoles acts as muscle relax-
ants [4] and show antimitotic activity [5]. Analgesic, anti-
inflammatory, anticonvulsive, diuretic and antiemetic
properties are exhibited by 5-aryl-2-hydroxymethyl-1,3,4-
oxadiazole derivatives [6], and 2-hydroxyphenyl-1,3,4-
oxadiazole acts as a hypnotic and as a sedative [7]. Some
material applications of 1,3,4-oxadiazole derivatives lie in
the fields of photosensitizes [8] and liquid cyrstals [9].
1,3,4-Oxadiazoles are associated with a broad spectrum
of biological activities including antifungal, antibacterial
and antitumor properties [10-12]. Several methods for the
synthesis of these biologically active compounds are
reported in literature [13-14].
Comp. No.
2 & 3
Y
R
X
a
b
c
d
e
f
g
h
i
Br
H
Br
H
Br
H
Br
H
Br
H
Br
H
CH
CH
4-C H
6
3
4
4
4
4
4-C H
3
6
C H
4-C H
6
5
5
6
C H
4-C H
6
6
CH
CH
CH
CH
CH
CH
3
2
2
2
2
Hydrazide derivatives have been extensively used as use-
ful precursors for the synthesis of these derivatives [15-16].
Keeping in view the biological importance of the above
mentioned heterocyclic compounds and in continuation to
our endeavor towards environmentally benign synthesis
[17], we report herein the synthesis of 6-substituted-3-[(5-
3
C H
6
5
5
C H
6
CH
CH
3-C H
3
6
4
4
4
4
j
k
l
3-C H
6
3
C H
3-C H
6
5
5
6
C H
3-C H
6
6

996
A. R. Desai and K. R. Desai
Vol. 42
Table Ia
Reaction Conditions for Microwave and Conventional Techniques 2(a-l) and 3(a-l)
Comp.
No.
Conventional
Yield
Comp.
No.
Microwave [a]
Yield
Time
(hr)
Time (min)
[b]
m.p/ºC
m.p/ºC
(%)
(%)
2a
2b
2c
2d
2e
2f
5.5
6.0
5.5
6.0
6.5
6.0
5.5
6.0
6.5
5.0
5.5
6.5
62
68
72
75
65
60
74
72
68
70
65
70
156~157
182
225
172
190~192
250
>300
110~115
152
245
221
3a
3b
3c
3d
3e
3f
7.0
6.5
7.5
7.0
6.0
7.5
6.5
7.0
7.5
6.5
7.0
6.5
85
88
90
82
92
85
80
78
82
86
88
85
192
175~177
152
221
242
280
148
164
182~184
205
2g
2h
2i
3g
3h
3i
2j
3j
2k
2l
3k
3l
210
272
252
[a] Microwave irradiations were carried out in a Kenstar microwave oven, model No. OM9925E (2450
MHz, 750 Watts); [b] Acidic Alumina.
Table 1b
Elemental Analysis and Physical Data of Compound 2(a-l) and 3(a-l)
Comp.
Formula
(Mr)
Anal. Calcd. (found) / %
Comp.
No.
Formula
(M.P/ºC)
Anal. Calcd. (found) / %
No.
2a
2b
2c
2d
2e
2f
C
H
N
C
H
N
C17H11BrN4O2S
(415)
C17H12N4O2S
(336)
C22H13BrN4O2S
(477)
C22H14N4O2S
(398)
C12H9BrN4O2S
(353)
C12H10N4O2S
(274)
C17H11BrN4O2S
(415)
C17H12N4O2S
(336)
C17H11BrN4O2S
(415)
C17H12N4O2S
(336)
C22H13BrN4O2S
(477)
C22H14N4O2S
(398)
49.17
(49.21
60.70
(60.72
59.35
(59.38
66.32
(66.34
40.81
(40.83
52.54
(52.51
49.17
(49.21
60.70
(60.72
49.52
(49.49
60.25
(60.27
59.98
(59.96
66.32
(66.34
2.67
2.64
3.60
3.58
3.52
3.49
3.54
3.51
2.57
2.61
3.67
3.69
2.67
2.64
3.60
3.57
2.85
2.83
3.21
3.18
3.22
3.25
3.54
3.51
13.49
13.52)
16.66
16.70)
9.28
3a
3b
3c
3d
3e
3f
C23H15BrN4O2
(459)
C23H16N4O2
(380)
C28H17BrN4O2
(521)
C28H18N4O2
(442)
C18H13BrN4O2
(397)
C18H14N4O2
(318)
C23H15BrN4O2
(459)
C23H16N4O2
(380)
C23H15BrN4O2
(459)
C23H16N4O2
(380)
C28H17BrN4O2
(521)
C28H18N4O2
(442)
60.15
(60.12
72.62
(72.58
64.50
(64.54
76.01
(76.04
54.43
(54.41
67.91
(67.93
60.15
(60.17
72.62
(72.65
60.28
(60.32
72.05
(72.03
64.94
(64.92
76.65
(76.68
3.29
3.32
4.24
4.21
3.29
3.31
4.10
4.08
3.30
3.32
4.43
4.45
3.29
3.31
4.24
4.27
3.42
3.41
4.65
4.63
3.52
3.48
4.18
4.22
12.20
12.22)
14.73
14.75)
10.75
10.78)
12.66
12.70)
14.10
14.12)
17.60
17.58)
12.20
12.25)
14.73
14.75)
12.85
12.82)
14.25
14.28)
10.20
10.18)
12.97
12.98)
9.25)
14.06
14.02)
15.86
15.82)
20.43
20.41)
13.49
13.52)
16.66
16.67)
13.85
13.87)
16.42
16.40)
9.75
2g
2h
2i
3g
3h
3i
2j
3j
2k
2l
3k
3l
9.72)
14.06
14.02)
1,3,4-oxadiazol-2-yl)phenyl]-2-substituedquinazolin-
4(3H)-one 2(a-l) and 6-substituted-3-[(5-phenyl-1,3,4-oxa-
diazol-2-yl) methyl]-2-substitutedquinazolin-4(3H)-one or
6-substituted-3-[4-(5-phenyl-1,3,4-oxadiazol-2-yl)phenyl]-
2-substitutedquinazolin-4(3H)-one 3(a-l).
substituedquinazolin-4(3H)-one 2(a-l) were prepared by
the cyclization of substituted anthranilic acid with acetyl
chloride or benzoyl chloride in presence of pyridine base.
Use of an appropriate amine viz p-amino benzoic acid or
glycine generated the corresponding 6-substituted-2-sub-
stiuted-4-oxoquinazolin-3(4H)-yl)benzoic acid or 6-sub-
stituted-2-substiuted-4-oxoquinazolin-3(4H)-yl)acetic
acid. This on subsequent chlorination with thionyl chloride
yields acid chlorides which on further reaction with
hydrazine hydrate yields hydrazides 1(a-l), the desired pre-
Results and Discussion.
6-Substituted-3-[(5-mercepto-1,3,4-oxadiazol-2-yl)-
methyl]-2-substituted quinaz-olin-4(3H)-one or 6-substi-
tuted-3-[4-(5-mercepto-1,3,4-oxadiazol-2-yl)phenyl]-2-

Jul-Aug 2005
Synthesis of 2-Aryl 1,3,4-Oxadiazole in Quinazolone
997
Table IIa
IR Spectral Analysis of Compound 2(a-l) and 3(a-l)
IR (KBr)
max/cm-1
Comp
No.
IR (KBr)
max/cm-1
Comp
No.
2a
2b
2c
1690 (C=O), 1593 (C=N), 1342 (C-O-C), 1267 (C=S),
540 (C-Br), 1310 (C-CH3).
1699 (C=O), 1595 (C=N), 1334 (C-O-C), 1269 (C=S),
1312 (C-CH3).
1710 (C=O), 1598 (C=N), 1335 (C-O-C), 1270 (C=S),
565 (C-Br).
3a
3b
3c
1699 (C=O), 1595 (C=N), 1334 (C-O-C), 565 (C-Br), 1312
(C-CH3).
1690 (C=O), 1593 (C=N), 1342 (C-O-C), 1315
(C-CH3).
1691 (C=O), 1594 (C=N), 1345 (C-O-C), 540 (C-Br).
2d
2e
1690 (C=O), 1593 (C=N), 1342 (C-O-C), 1267 (C=S).
1691 (C=O), 1594 (C=N), 1345 (C-O-C), 1271 (C=S),
540 (C-Br), 1315 (C-CH3).
3d
3e
1715 (C=O), 1589 (C=N), 1348 (C-O-C).
1698 (C=O), 1593 (C=N), 1350 (C-O-C), 558 (C-Br), 1310
(C-CH3).
2f
1715 (C=O), 1589 (C=N), 1348 (C-O-C), 1258 (C=S),
1308 (C-CH3).
3f
1695 (C=O), 1590 (C=N), 1339 (C-O-C), 1312
(C-CH3).
2g
1710 (C=O), 1582 (C=N), 1352 (C-O-C), 1255 (C=S),
545 (C-Br)
3g
1705 (C=O), 1599 (C=N), 1332 (C-O-C), 542 (C-Br).
2h
2i
1698 (C=O), 1593 (C=N), 1350 (C-O-C), 1262 (C=S)
1705 (C=O), 1605 (C=N), 1345 (C-O-C), 1272 (C=S),
548 (C-Br), 1308 (C-CH3).
3h
3i
1695 (C=O), 1590 (C=N), 1339 (C-O-C).
1700 (C=O), 1602 (C=N), 1352 (C-O-C), 560 (C-Br),
1311 (C-CH3).
2j
2k
2l
1699 (C=O), 1595 (C=N), 1334 (C-O-C), 1269 (C=S),
1312 (C-CH3).
1695 (C=O), 1595 (C=N), 1348 (C-O-C), 1258 (C=S),
560 (C-Br).
3j
3k
3l
1690 (C=O), 1593 (C=N), 1342 (C-O-C), 1309
(C-CH3).
1710 (C=O), 1598 (C=N), 1335 (C-O-C), 572 (C-Br).
1692 (C=O), 1600 (C=N), 1345 (C-O-C), 1272 (C=S).
1699 (C=O), 1598 (C=N), 1345 (C-O-C).
Table IIb
1H nmr Spectral Analysis of Compounds 2(a-l) and 3(a-l)
No.
1H nmr / ppm
No.
1H nmr / ppm
2a
2b
2c
2d
2e
2f
2.54 (s, 3H, Me), 7.05-8.18 (m, 7H, Ph & H-5, H-7-8), 9.54 (s, br,
1H, NH).
2.50 (s, 3H, Me), 7.15-8.10 (m, 8H, Ph & H-5-8),
9.68 (s, br, 1H, NH).
2.25 (s, 3H, Me), 7.10-8.25 (m, 13H, 2Ph & H-5, H-7-8),
9.72 (s, br, 1H, NH).
2.62 (s, 3H, Me), 7.20-8.30 (m, 14H, 2Ph & H-5-8),
9.40 (s, br, 1H, NH).
2.52 (s, 3H, Me), 7.15-8.19 (m, 3H, H-5, H-7-8), 9.58
(s, br, 1H, NH), 5.58 (s, 2H, NCH2N).
2.58 (s, 3H, Me), 7.07-8.17 (m, 4H, H-5-8), 9.19
(s, br, 1H, NH), 5.45 (s, 2H, NCH2N).
2.72 (s, 3H, Me), 7.19-8.20 (m, 8H, Ph, H-5, H-7-8), 9.29
(s, br, 1H, NH), 5.44 (s, 2H, NCH2N).
2.54 (s, 3H, Me), 7.03-8.15 (m, 9H, H-5-8), 9.55
(s, br, 1H, NH), 5.41 (s, 2H, NCH2N).
2.55 (s, 3H, Me), 7.12-8.25 (m, 7H, Ph & H-5, H-7-8), 9.16 (s, br,
1H, NH).
3a
3b
3c
3d
3e
3f
2.62 (s, 3H, Me), 7.15-8.18 (m, 12H, 2Ph & H-5, H-7-8).
2.25 (s, 3H, Me), 7.12-8.20 (m, 13H, 2Ph & H-5-8).
2.42 (s, 3H, Me), 7.08-8.32 (m, 17H, 3Ph & H-5, H-7-8).
2.64 (s, 3H, Me), 7.21-8.10 (m, 18H, 2Ph & H-5-8).
2.58 (s, 3H, Me), 7.14-8.28 (m, 8H, Ph & H-5, H-7-8),
5.52 (s, 2H, NCH2N).
2.42 (s, 3H, Me), 7.09-8.21 (m, 9H, Ph & H-5-8),
5.45 (s, 2H, NCH2N).
2.25 (s, 3H, Me), 7.25-8.21 (m, 13H, 2Ph, H-5, H-7-8), 5.54 (s,
2H, NCH2N).
2.48 (s, 3H, Me), 7.07-8.18 (m, 14H, Ph & H-5-8),
5.65 (s, 2H, NCH2N).
2g
2h
2i
3g
3h
3i
2.68 (s, 3H, Me), 7.12-8.25 (m, 12H, 2Ph & H-5, H-7-8).
2j
2.60 (s, 3H, Me), 7.10-8.12 (m, 8H, Ph & H-5-8),
9.28 (s, br, 1H, NH).
2.48 (s, 3H, Me), 7.07-8.24 (m, 13H, 2Ph & H-5, H-7-8),
9.32s, br, 1H, NH).
2.54 (s, 3H, Me), 7.03-8.17 (m, 14H, 2Ph & H-5-8),
9.54s, br, 1H, NH).
3j
2.44 (s, 3H, Me), 7.09-8.19 (m, 13H, 2Ph & H-5-8).
2.54 (s, 3H, Me), 7.04-8.12 (m, 17H, 3Ph & H-5, H-7-8).
2.58 (s, 3H, Me), 7.14-8.18 (m, 18H, 2Ph & H-5-8).
2k
2l
3k
3l
cursor for one pot synthesis of 2-aryl or 2-mercepto 1,3,4-
oxadiazole incorporated into quinazolone derivatives.
The compound 1(a-l) on reaction with carbon disulphide in
the presence of potassium hydroxide yields the title compound
6-substituted-3-[(5-mercepto-1,3,4-oxadiazol-2-yl)methyl]-2-
substituted quinazoline-4(3H)-one or 6-substituted-3-[4-(5-
mercepto-1,3,4-oxadiazol-2-yl)phenyl]-2-substitued quina-
zolin-4(3H)-one 2(a-l). Moreover the compound 1(a-l) on
microwave irradiation in the presence of acidic alumina cata-
lyst with carboxylic acid yields the title compounds 6-substi-
tuted-3-[(5-phenyl-1,3,4-oxadiazol-2-yl)methyl]-2-substitut-
edquinazolin-4(3H)-one or 6-substitut- ed-3-[4-(5-phenyl-
1,3,4-oxadiazol-2-yl)phenyl]-2-substitutedquinazolin-4(3H)-
one 3(a-l). This proved to be a high-yielding protocol.

998
A. R. Desai and K. R. Desai
Vol. 42
Table III
Antibacterial and Antifungal Activity of Compound 2(a-l) and 3(a-l)
compound
Antibacterial in (µg/ml)
Gram positive
Antifungal in (µg/ml)
Candida C.krusei
Gram negative
S.a[a]
7
9
15
8
-
B.s[b]
12
0.8
-
E.c[c]
19
6
12
10
9
P.a[d]
13
0.9
9
ATCC 10231
G03
15
0.9
9
2a
2b
2c
2d
2e
2f
2g
2h
2i
-
10
15
22
-
0.9
10
-
0.7
7
-
21
7
-
25
-
22
0.9
-
21
0.4
25
8
7
0.8
8
10
20
0.8
9
12
-
20
17
8
0.7
0.8
-
15
8
8
-
-
10
18
8
0.2
12
-
25
10
0.8
21
8
15
12
0.9
-
0.9
12
-
25
7
-
8
9
12
8
7
12
7
28
12
-
15
10
0.8
-
2j
2k
2l
-
12
15
1.1
10
12
1.8
18
-
12
17
9
-
10
3a
3b
3c
3d
3e
3f
3g
3h
3i
-
12
17
-
20
0.9
10
17
10
7
9
5
15
20
1.1
20
15
10
-
10
12
15
-
9
24
3j
3k
3l
12
10
0.9
10
17
12
10
18
Zone of Inhibition of Standard Drugs (µg/ml)
Ampicillin
Amoxicillin
Penicillin
40
35
40
-
45
40
38
-
40
38
42
-
50
45
48
-
-
-
-
-
-
-
Flucanozole
40
35
[a] S.a- S.aureus; [b] B.s- B.subtilis; [c] E.c-E.coli; [d] P.a-P.aeruginosa.
melting point apparatus and are uncorrected. The ir spectra
were recorded in KBr on a Perkin-Elmer RX 1 FT-IR
Spectrophotometer (serial No. 51448) and H nmr spectra was
The Structure of 2(a-l) and 3(a-l) were confirmed on the
basis of spectral and analytical data. IR spectra showed
1
-1
-1
appearance of bands at 1699 cm (C=O), 1600 cm
recorded in CDCl with TMS as an internal Standard on 300
3
-1
(C=N) for formation of quinazolone and 1590 cm (C=N),
MHz Bruker A/C 300 F Spectrophotometer.
-1
-1
1339 cm (C-O-C), 1267 cm (C=S) for formation of 2-
mercepto-1,3,4-oxadiazole. Similarly by appearance of
Preparation of 2-(6-Bromo-2-methyl-4-oxoquinazolin-3(4H)-yl)-
benzohydrazide 1(a-l).
-1
-1
bands at 1595 cm (C=N), 1342 cm (C-O-C) for 2-aryl-
To a solution of 3.77 g (0.01 mole) of 4-(6-bromo-2-methyl-4-
oxo-quinazolin-3(4H)-yl) benzoyl chloride in ethanol was added
0.48 g (0.01 mole) hydrazine hydrate slowly with constant stir-
ring and the reaction mixture was refluxed for 6-8 hrs in a 250
mL round bottom flask. The solvent was then removed by distil-
lation under reduced pressure and the residue was poured into
ice-cold water, and recrystallised by using ethanol. The yield
1
1,3,4-oxadizole. In H nmr, appearance of the signal at δ
7.1-8.1 (m, 3H, H-3, H-7-8), 9.54 (s, br, 1H, NH) for 2(a-l)
and 7.05-8.18 (m, 8H, Ph, H-3, H-7-8) for 3(a-l). Reaction
conditions and % yields for microwave and conventional
techniques are shown in Table-Ia. Elemental analysis and
physical data are shown in Table-Ib. The compounds are
3.23 g (76%), mp 220 °C; ir (potassium bromide): 1690 (C=O),
1
confirmed on the basis of ir (Table-IIa) and H nmr (Table-
-1
1600 (C=N), 1710 (C=O), 3394, 3284 (NH ), 3218 (NH) cm ;
2
IIb) spectral studies. The reaction pathways are depicted in
Scheme 1.
1
H nmr (CDCl ): δ 2.54 (s, 3H, Me), 7.05-8.18 (m, 7H, Ph & H-
3
5, H-7-8), 8.77 (s, br, 1H, NH), 5.88 (br, 2H, NH ).
2
Anal. Calcd. For C H BrN O : C, 51.49; H, 3.51; N, 15.01.
16 13
2 4
Found: C, 51.52; H, 3.49; N, 15.04.
EXPERIMENTAL
Preparation of 6-Bromo-3-[4-(5-mercepto-1,3,4-oxadizole-2-
All melting points were determined in PMP-DM scientific
yl)phenyl]-2-methyl quinazoline-4(3H)-one 2(a-l).

Jul-Aug 2005
Synthesis of 2-Aryl 1,3,4-Oxadiazole in Quinazolone
999
To a solution of 3.73 g (0.01 mole) 2-(6-bromo-2-methyl-4-
oxoquinazolin-3(4H)-yl)-benzohydrazide in ethanol (50 mL)
was added potassium hydroxide 0.56 g (0.01 mole) and carbon
disulphide (3 mL) in a 250 mL round bottom flask. The reaction
mixture was refluxed until the evolution of hydrogen sulphide
ceased. The reaction mixture was concentrated, dissolved in
water and acidified with HCl. The precipitate was collected by
filtration, washed, dried and recrystallised from ethanol to give
6-bromo-3-[4-(5-mercepto-1,3,4-oxadizole-2-yl)phenyl]-2-
methyl-quinazoline-4(3H)-one. The yield 3.50 g (62%), mp
156~157 °C; ir (potassium bromide): 1690 (C=O), 1593 (C=N),
2j, 3a, 3f, 3h and 3k showed significant antibacterial activity.
Compound 2d, 2e, 2f, 2l, 3a, 3e, 3f and 3l showed moderate to
good antifungal activity (Table-III).
Acknowledgment.
The authors are thankful to the Head, Department of chem-
istry, Veer Narmad South Gujarat University, Surat for providing
research facilities and screening of ir spectra. The authors are
also thankful to Quest institute of life sciences, C/O Nicholas
Piramal ltd, Mumbai for screening of antifungal and antibacterial
1
activity and CDRI, Lucknow for providing H nmr spectra and
-1
1
1342 (C-O-C), 1267 (C=S) cm ; H nmr (DMSO-d ): δ 2.54 (s,
6
elemental analysis.
3H, Me), 7.05-8.18 (m, 7H, Ph & H-5,H-7-8), 9.54 (s, br, 1H,
NH).
REFERENCES AND NOTES
Anal. Calcd. For C H BrN O S: C, 49.17; H, 2.67; N, 13.49.
17 11
4 2
Found: C, 49.21; H, 2.65; N, 13.52.
[1] W. Xie, Y. Jin and P. G. Wang, Chemtech., 29, 23 (1999).
[2] R. S. Verma, Green Chem., 1, 43 (1999).
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[5] D. Ghiran, I. Schwartz and I. Simiti, Farmacia., 22, 141
(1974).
[6] J. Thomas, German Patent 2403357 (1974); Chem. Abstr.,
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[7] G. W. Adelstein, C. H. Yen, E. Z. Dajani and R. G.
Bianchi, J. Med. Chem. 19, 1221 (1976).
[8] E. Schinzel, T. Martini, W. Spatzeier, H. Probst and A. G.
Hoechst and De. Patent 3126464 (1983/1981); Chem Abstr., 98,
199850 (1983).
[9] N. K. Chudhgar, S. N. Shah and R. A. Vora, Mol. Cryst.
Liq. Cryst., 51, 172 (1989).
[10] Y. Gan, D. Lu, J. Liu and M. Tian, Zhongguo Yaouri
Zazhi, 11, 85 (2001); Chem Abstr., 136, 216696 (2002).
[11] G. Turan-Zitouni, M. Sivaci, F. S. Kilic and K. Erol, Eur.
J. Med. Chem., 36, 685 (2002).
[12] S. Sharma, V. K. Srivastava and A. Kumar, Eur. J. Med.
Chem., 37, 689 (2002).
[13] J. C. Jung, E. B. Watkins and M. A. Avery, Tetrahedron.,
58, 3696 (2002)
[14] V. K. Ahluwalia and S. Dudeja, Synth. Commun., 31, 3175
(2001).
[15a] R. S. Sharma and S. C. Bahel, J. Ind. Chem. Soc., 59, 877
(1982); [b] S. A. Shiba, A. A. El-Khamry, M. E. Shaban and K. S.
Atia, Indian J. Chem., 36B, 361 (1997).
[16] J. C. Jung, E. B. Watkins and M. A. Avery, Synth.
Commun., 32, 3767 (2002).
[17a] M. Kidwai, S. Saxena, R. Mohan and R. Venkataramanan,
J. Chem. Soc., Perkin Trans 1. 16, 1845 (2002); [b] M. Kidwai, S.
Rastogi and R. Venkataramanan, Bull. Chem. Soc. Jpn., 76, 203
(2003).
Preparation of 6-Bromo-2-methyl-3-[4-(5-phenyl-1,3,4-oxadi-
zole-2-yl)phenyl]-quinazoline-4(3H)-one 3(a-l).
To a solution of 3.73 g (0.01 mole) 2-(6-bromo-2-methyl-4-
oxoquinazolin-3(4H)-yl)-benzohydrazide in ethanol (50 mL) was
added benzoic acid 1.22 g (0.01 mole) in 100 mL beaker, acidic
alumina (20 g) was added as a solid support catalyst. The reaction
mixture was stirred well and dried in air. It was then placed in an
alumina bath and subjected to microwave irradiation (MWI)
intermittently at an interval of 30s for specified time (Table Ia).
On completion of reaction, as monitored by TLC examination,
the product was extracted into ethanol (3x15 mL). Removal of
solvent under reduced pressure gave the desired product which
was recrystallised from ethanol. The yield 4.25 g (85%), mp 192;
ir (potassium bromide): 1695 (C=O), 1590 (C=N), 1339 (C-O-C)
-1 1
cm ; H nmr (DMSO-d ): δ 1.2 (s, 3H, Me), 7.05-8.18 (m, 12H,
6
2Ph & H-5, H-7-8).
Anal. Calcd. For C H BrN O : C, 60.15; H, 3.29; N, 12.20.
23 15
4 2
Found: C, 60.12; H, 3.27; N, 12.18.
Conclusion.
Similarly 2-(6-bromo-2-phenyl-4-oxoquinazolin-3(4H)-yl)-
benzohydrazide or 2-(6-bromo-2-phenyl-4-oxoquinazolin-
3(4H)-yl)-acetohydrazide and other substituted quinazolone
hydrazide can be prepared by using amino carboxylic acid in
conjugation with acetyl or benzoyl chloride. All compounds were
screened for their antifungal activity against Candida albicans
and antibacterial against S.aureus, B.subtilis, E.coli and P.aerug-
inosa. Zone of inhibition were measured in millimeters. The anti-
fungal activities were compared to the standard drug flucanozole
(35-40 mm) with DMF as solvent. Ampicillin (40-50 mm),
Amoxicillin (35-45 mm) and penicillin (38-48 mm) were used as
standard drugs for antibacterial activity. Compounds 2e, 2h, 2i,