Some new 2,3,6-trisubstituted quinazolinones as potent anti-inflammatory, analgesic and COX-II inhibitors

Article abstract of DOI:10.1016/S0968-0896(03)00501-7

Various 2-(substitutedphenylmethyleneimino)aminoacetylmethylene-3- (2′-substitutedindol-3′-yl)-halosubstituted-4(3H)quinazolinones (5a-5i) and 2-(substituted phenylaminomethyleneacetyl-4′-oxo-1′- thiazolidinyl-3-(2″-substitutedindol-3″-yl) 4(3H)-quinazolinones (6a-6i) have been synthesized in the present studies. The structure of these compounds have been elucidated by elemental (C, H, N) and spectral (IR, ¹H NMR and mass) analysis. Furthermore, above said compounds were evaluated for their anti-inflammatory, analgesic, ulcerogenic activities and acute toxicity study. Compound 6d was found to be most potent. Compound exihibiting less ulcerogenic liability and ALD₅₀ >2000 mg/kg po.

Full text of DOI:10.1016/S0968-0896(03)00501-7

Bioorganic & Medicinal Chemistry 11 (2003) 5293–5299
Some New 2,3,6-Trisubstituted Quinazolinones as Potent
Anti-inflammatory, Analgesic and COX-II Inhibitors
Ashok Kumar,* Shalabh Sharma, Archana, Kiran Bajaj, Shipra Sharma,
Hemant Panwar, Tripti Singh and V. K. Srivastava
Medicinal Chemistry Division, Department of Pharmacology, L.L.R.M Medical College, Meerut (U.P.)-250004, India
Received 12 May 2003; accepted 4 July 2003
Abstract—Various
2-(substitutedphenylmethyleneimino)aminoacetylmethylene-3-(20-substitutedindol-30-yl)-halosubstituted-
4(3H)quinazolinones (5a–5i) and 2-(substituted phenylaminomethyleneacetyl-40-oxo-10-thiazolidinyl-3-(200-substitutedindol-300-yl)
4(3H)-quinazolinones (6a–6i) have been synthesized in the present studies. The structure of these compounds have been elucidated
1
by elemental (C, H, N) and spectral (IR, H NMR and mass) analysis. Furthermore, above said compounds were evaluated for
their anti-inflammatory, analgesic, ulcerogenic activities and acute toxicity study. Compound 6d was found to be most potent.
Compound exihibiting less ulcerogenic liability and ALD50 >2000 mg/kg po.
# 2003 Elsevier Ltd. All rights reserved.
Introduction
Results
Chemistry
Recently developed non acidic or weakly acidic
NSAIDs like celecoxib1, rofecoxib1 and so on have
drawn the attention of medicinal chemists as they pre-
ferentially act by inhibiting COX-II enzyme and pos-
sessed lower incidence of gastric ulcers than the acidic
NSAIDs which inhibit both COX-I and COX-II enzyme
like indomethacin, aspirin, naproxen and so on. Fur-
thermore, a large number of quinazolinones2À4 have
been reported to possess potent anti-inflammatory and
analgesic activities. However, the substitution pattern in
the quinazolinone nucleus at 2/3 position5,6 by different
aryl or heteo aryl moieties markedly modulates its anti-
inflammatory activity. Moreover, indole7,8 and thiazoli-
dinone9,10 derivatives have also been reported to possess
potent anti-inflammatory activity. There are very few
reports in the literature that quinazolinones derivatives
reduce the inflammation in different inflammatory dis-
orders by inhibiting the COX-II enzyme. Hence, it was
thought worthwhile to synthesize some new 2,3,6-tri-
substituted quinazolinone derivatives with the hope to
possess better anti-inflammatory potential and lesser
side effect than the already existing COX-II inhibitors.
All the compounds were tested pharmacologically for
their anti-inflammatory, analgesic, ulcerogenic, toxicity
and COX-II inhibiting activity.
The starting compound, that is monobromoanthranilic
acid and 5 iodoanthranilic acid, were prepared according
to reported method by Wheelar et al.11 and Klemme et
al.12 respectively compound 1 was also synthesized by
known method.13 2-Methyl-3-(20-substitutedindol-3-yl)-
6-halosubstituted-4(3H)-qunizolinones (2a–2c) were
prepared by the reaction of different acetanthranils with
2-substituted-3-aminoindoles in dry pyridine. These
were on treatment with chloroacetyl chloride yielded the
compounds (3a–3c). The later compounds were refluxed
with hydrazine hydrate to obtain 2-hydrazinoacetyl
methylene-3-(20-substitutedindol-3-yl)-6-halosubstituted-
4(3H) quinazolinones (4a–4c). These compounds were
further refluxed with various aromatic aldehydes in the
presence of glacial acetic acid to obtain 2-(substituted
phenyl methyleneimino)aminoacetylmethylene - 3 - (20-
substituedindol - 30 - yl) - 6 - halosubstituted quinazolin-
4(3H)-ones (5a–5i). Furthermore, 2-substitutedphenyl-
aminomethylacetyl{40 - oxo - 10 - thiazolidinyl}-3-(200-sub-
stitutedindol-300-yl)-quinazolin-4(3H)-ones (6a–6i) were
synthesized by reacting compounds 5a–i with thiogly-
colic acid in the presence of anhydrous ZnCl2. The syn-
thetic pathway of the above said compounds is shown in
Scheme 1. The structure of all the newly synthesized
compounds was confirmed on the basis of spectral (IR,
1H NMR and mass) and analytical data.
*Corresponding author. E-mail: rajput_ak@indiatimes.com
0968-0896/$ - see front matter # 2003 Elsevier Ltd. All rights reserved.
doi:10.1016/S0968-0896(03)00501-7

5294
A. Kumar et al. / Bioorg. Med. Chem. 11 (2003) 5293–5299
Pharmacological evaluation
and cycloxygenas-II inhibiting activities. The important
feature of the compounds 5a–5i is the presence of 20-
substitutedindol-30-yl moiety at the 3-position of quina-
zolinone nucleus and substituted phenyliminoamino-
acetyl-methylene chain at the 2-position of the quina-
zolinone moiety. These compounds 5a–5i were eval-
uated at a dose of 50 mg/kg po for their anti-
inflammatory and analgesic activities. From the results,
it seems that compound 5a having 2-methoxyphenyl
ring showed less potent activities, but exhibited better
activities than compound 5b possessing 4-methoxy-
phenyl group as substitution. However, compound 5c
exhibited more potent activities than the compounds 5a
and 5b. Among these compounds, compound 5f was
found to possess most potent anti-inflammatory and
analgesic activities and less ulcerogenic potentialities
than other compounds.
Random screening of the compounds 5a–5i and 6a–6i
was performed at 50 mg/kg po for their anti-inflamma-
tory and analgesic activities. Compounds 5f and 6d were
found to possess more potent activities than phenyl-
butazone, reference drug, and the rest of the compounds
of this series. Furthermore, these two compounds and
phenylbutazone were evaluated at three graded doses,
that is 25, 50 100 mg/kg po for their anti-inflammatory
and analgesic activities. All compounds of this series
were also screened for their acute toxicity, ulcerogenic,
liability and COX-II inhibitory activity interestingly,
these two compounds, that is 5f and 6d possessed less
ulcerogenic liability and showed ALD50>1000 mg/kg
po and >2000, respectively. The results of the biologi-
cal study are depicted in Table 1.
Furthermore, cyclization of compounds 5a–5i in to their
corresponding compounds 6a–6i in general enhances the
activities. The characteristic feature of compounds 6a–6i
is the presence of thiazolidinyl moiety at the 2-position
of quinazolinone nucleus. The compound 6d having 2-
Discussion
Compounds 5a–5i and 6a–6i have been tested for their
acute toxicity, anti-inflammatory, analgesic, ulcerogenic
Table 1. Pharmacological evaluation of compounds 5a–5i and 6a–6i
Comd.
No.
X
R
R0
Anti-inflammatory Analgesic
activity
Ulcerogenic
activity
COX-II
ED50
ALD50
activity
inhibitory mg/kg p.o. mg/kg p.o.
activity
Dose
(mg/kg inhibitor
% oedema Dose
%
Dose % of
% of
animal with animal
(mg/kg decreases
p.o.)
p.o.)
relation
hypermia
with ulcer
5a
5b
5c
5d
5e
5f
H
H
H
6-I
6-I
6-I
CH3 2-OCH3
CH3 4-OCH3
CH3 2-Cl
50
50
50
50
50
25
50
100
50
50
50
50
50
50
25
50
100
50
50
50
50
50
25
38.7
31.6
49.2
52.6
44.8
40.2
58.9
79.9
49.7
43.5
55.3
32.6
28.2
29.7
39.6
60.4
82.4
52.7
58.3
50.1
46.3
57.1
28.42
50
50
50
50
50
25
50
100
50
50
50
50
50
50
25
50
100
50
50
50
50
50
30
20
40
60
50
40
70
90
70
60
80
40
30
40
30
70
80
60
50
60
60
70
300
300
300
300
300
100
200
300
300
300
300
300
300
300
100
200
300
300
300
300
300
300
60
30
20
100
90
50
70
90
60
50
50
80
70
50
30
60
100
90
80
100
80
90
30
40
10
20
30
20
30
40
20
40
50
30
40
40
10
10
10
20
30
40
50
40
ni
ni
ni
ni
ni
—
—
—
—
—
> 1000
> 1000
> 1000
> 1000
> 1000
H
H
H
2-OCH3
4-OCH3
4-Cl
40
35.4
> 1000
5g
5h
5i
6a
6b
6c
6d
6-Br CH3 2-OCH3
6-Br CH3 N-(CH3)2
6-Br CH3 2-Cl
H
H
ni
ni
ni
ni
ni
ni
—
—
—
—
—
—
> 1000
> 1000
> 1000
> 1000
> 1000
> 1000
CH3 2-OCH3
CH3 4-OCH3
CH3 2-Cl
H
6-I
H
2-OCH3
90
35.4
> 2000
6e
6f
6g
6h
6i
Phenyl
butazone
6-I
6-I
H
H
4-OCH3
4-Cl
ni
ni
ni
ni
ni
—
—
—
—
—
> 1000
> 1000
> 1000
> 1000
> 1000
6-Br CH3 2-OCH3
6-Br CH3 N-(CH3)2
6-Br CH3 2-Cl
—
—
—
—
—
—
50
100
5.0
7.0
10
36.4
58.4
52.2
63.1
93.2
—
—
—
—
—
—
—
—
—
—
—
—
—
—
Indomethacin
—
—

A. Kumar et al. / Bioorg. Med. Chem. 11 (2003) 5293–5299
5295
IR spectra (KBr/Nujol) were recorded on Beckman
Acculab-10-FTIR spectrometers. 1H NMR spectra were
recorded by Bruker DRX-300 FTNMR instrument
using CDCl3 or DMSO-d6 as solvent and tetramethyl
silane (TMS) as internal reference standard. All chemi-
cal shift (d) values were recorded in ppm. The purity of
the compounds was checked by thin-layer chromato-
graphy on silica gel G plates of 0.5-mm thickness. The
elemental analysis (C, H, N) of the compounds was
performed on a Carlo Erba-1108 instrument.
2-Methyl-3-(20 -methylindol-30 -yl)-4(3H)-quinazolinone
(2a). To
a
solution of 2-methyl-3-aminoindole
(0.01 mol) in dry pyridine (100 mL) different acetan-
thranils (0.02 mol) was added. The reaction mixture was
refluxed for 10 h. After refluxing, excess of solvent was
removed and the residue neutralized with HCl. The
solid separated out was washed with water and recrys-
tallized from ethanol to give 2a (85%): mp 214 ꢀC. IR
(KBr) n 3250, 3045, 1690, 1608 and 1155 cmÀ1 1H
;
NMR (CDCl3) d 8.60–7.95 (8H, m), 9.01 (1H, s), 2.20
(6H, s) ppm. Anal. calcd for C18H15N3O: C, 74.74; H,
5.19; 14.53. Found: C, 74.93; H, 5.37; N, 14.72. The
following compounds were prepared using a similar
procedure described for 2a.
2-Methyl-3-(indol-30-yl)-6-iodo-4(3H)-quinazolinone (2b).
Mp 247–248 ꢀC (DMF/water); IR (Nujol) n 3255, 3040,
1
2965, 1692, 1610, 1150 and 730 cmÀ1; H NMR d 8.62–
7.95 (7H, m), 9.05 (1H, s), 2.15 (3H, s) ppm. Anal. calcd
for C17H11IN3O: C, 50.87; H, 2.75; N, 10.50. Found: C,
51.02 ; H, 2.92 ; N, 10.65.
2-Methyl-3-(20 -methylindol-30 -yl)-6-bromo-4(3H)-quina-
zolinone (2c). Mp 277–278 ꢀC (acetic acid/water); IR
(Nujol) n 3250, 2960, 1695, 1605, 1155 and 560 cmÀ1; 1H
NMR (CDCl3) d 8.60–7.98 (7H, m), 9.05 (1H, s), 2.18
(6H, s) ppm. Anal. calcd for C18H14BrN3O: C, 58.69; H,
3.80; N, 11.41. Found: C, 58.72; H, 3.97; N, 11.67.
Scheme 1.
methoxyphenyl group as substituent was found to be
the most potent derivative of the present series. Being a
most potent compound, this compound was further
screened for their anti-inflammatory and analgesic prop-
erties at three graded doses, that is 25, 50 and 100 mg/kg
po; interestingly, this compound showed better activities
than the standard drugs at all doses tested. As far as the
ulcerogenic liability of these compounds is concerned,
the compounds 5f and 6f exhibit less ulcerogenic poten-
tialities than the rest of the compounds of this series.
2-Chloroacetylmethylene-3-(20-methyl-indol-30-yl)-4(3H)-
quinazolinone (3a). To a solution of 2-methyl-3-(20-
methyl-indol-30-yl)-4(3H)-quinazolinone 1a (0.32 mol)
in dry THF (200 mL) was added at 0 ꢀC temperature
drop by drop along with manual stirring for 2 h. The
reaction mixture was further stirred for 4 h at room
temperature on mechanical stirrer. After stirring, excess
of solvent was distilled off, cooled, poured onto crushed
ice and filtered. The solid thus obtained was recrys-
All these compounds were also evaluated for COX-II
inhibitory activity, and only compounds 5f and 6d
showed COX-II inhibitory action, that is 40 and 90%
inhibition, respectively. Compound 6d exhibited ALD50
>2000 mg/kg po and the rest of the compounds of this
series showed ALD50>1000 mg/kg po.
ꢀ
tallized from methanol to yield 3a (75%): mp 176 C;
IR (KBr) n 3265, 3062, 2910, 1700, 1610, 1580 and
1
580 cmÀ1; H NMR (CDCl3) d 8.55–7.90 (8H, m), 9.10
(1H, s), 2.20 (3H, s), 4.10 (2H, s) 3.90 (2H, s) ppm.
Anal. calcd for C20H16ClN3O2: C, 65.55; H, 4.38;
N,11.49. Found: C, 65.73; H, 4.56; N, 11.57. The fol-
lowing compounds were prepared using a similar pro-
cedure described for 3a.
Experimental
Chemistry
2-Chloroacetylmethylene-3-(indol-30 -yl)-6-iodo-4(3H)-
Melting points were determined in open capillaries with
the help of thermonic melting point apparatus and are
uncorrected. Homogeneity of the newly synthesized
compounds was checked by thin layer chromatography.
quinazolinone (3b). Mp 202–203 ꢀC (ethanol): IR (KBr)
n 3265, 2960, 1708, 1603, 1585, 575 cmÀ1 1H NMR
;
(CDCl3) d 8.55–7.95 (8H, m), 9.12 (1H, s), 4.08 (2H, s),
3.91(2H, s) ppm. Anal. calcd for C19H13ClIN3O2: C,

5296
A. Kumar et al. / Bioorg. Med. Chem. 11 (2003) 5293–5299
1
47.75; H, 2.72; N, 8.79. Found: C, 47.92; H, 3.03; N,
8.91.
1715, 1603 cmÀ1; H NMR (CDCl3) d 8.50–7.75 (12H,
m), 9.15 (1H, s), 2.20 (3H, s), 4.15 (2H, s), 3.18 (3H, s)
ppm. Anal. calcd for C28H25N5O3; C, 70.14; H, 5.21; N,
14.61. Found: C, 70.27; H, 5.57; N, 14.25.
2-Chloroacetylmethylene - 3 - (20 - methylindol - 30 - yl)-6-
bromo-4(3H)-quinazolinone (3c). Mp 245–246 ꢀC (ace-
tone/pet. ether); IR (Nujol) n 3270, 3050, 1710, 1605,
2-(o-Chlorophenylmethyleneimino)aminoacetylmethylene
-3-(20 -methyl-indol-30-yl)-4(3H)-quinazolinone (5c). Mp
184–185 ꢀC (methanol/water); IR (KBr) n 3270, 3065,
1
1585, 570 and 550 cmÀ1; H NMR (CDCl3) d 8.55–7.92
(7H, m), 9.10 (1H, s), 4.10 (2H, s), 2.20 (3H, s), 3.95
(2H, s) Anal. calcd for C20H15BrClN3O2: C, 53.99; H,
3.37; N, 9.45. Found: C, 54.12; H, 3.26; N, 9.32.
2965, 1712, 1603, 1580, 1205, 560 cmÀ1 1H NMR
;
(DMSO-d6) d 8.55–7.80 (12H, m), 9.16 (1H, s), 2.18
(3H, s), 4.16 (2H, s), 3.90 (2H, d), 5.65 (1H, t), 6.15 (1H,
s) ppm. Anal. calcd for C27H22ClN5O2; C, 67.01; H,
4.55; N, 14.47. Found: C, 66.05; H, 4.26; N, 14.83.
2-Hydrozinoacetylmethylene - 3 - (20 - methylindol - 30yl)-
4(3H)-quinazolinone (4a). A mixture of compound 2a
and hydrazine hydrate (99%) in absolute ethanol
(50 mL) was refluxed for 12 h and the completion of the
reaction was monitored by TLC. Excess of solvent was
distilled off and the reaction mixture was poured onto
crushed ice and then filtered. The solid thus obtained
was recrystallized from ethanol/water to yield 4a (80%):
mp 214–215 ꢀC; IR (KBr) n 3350, 3272, 1710, 1603,
2-(o,-Methoxyphenylmethyleneimino)aminoacetylmethyl-
ene-3-(indol-30-yl)-6-iodo-4(3H)-quinazolinone (5d). Mp
155–156 ꢀC (ethanol/water). IR (KBr) n 3275, 1715,
1600, 1585, 752 cmÀ1; H NMR (CDCl3) d 8.55–7.75
1
(12H, m), 9.18 (1H, s), 4.20 (2H, s), 3.90 (2H, d), 5.65
(1H, t), 6.15 (1H, s), 3.20 (3H, s). Anal. calcd for
C27H22IN5O3: C, 54.82; H, 3.72; N, 11.84: Found: C,
54.57; H, 3.59; N, 12.00.
1
2960, 1580 cmÀ1; H NMR (CDCl3) d 8.57–7.95 (8H,
m), 9.15 (1H, s), 4.10 (2H, s), 3.90 (2H, d), 5.85–5.70
(3H, m), 2.18 (3H, s) ppm. Anal. calcd for C20H19N5O2:
C, 66.48 ; H, 5.26 ; N, 19.39. Found: C, 66.62; H, 5.31;
N, 19.47. The following compounds were synthesized by
adopting a similar procedure described for 4a.
2-(p-Methoxyphenylmethyleneimino)aminoacetylmethyl-
ene-3-(indol-30-yl)-6-iodo-4(3H)-quinazolinone (5e). Mp
184–186 ꢀC (DMF/water); IR (Nujol) 3275, 3062, 1720,
1582,750 cmÀ1;1H NMR (CDCl3) d 8.60–7.80 (12H, m),
9.20 (1H, s), 4.22 (2H, s), 3.92 (2H, d), 5.62 (1H, t), 6.20
(1H, s), 3.20 (3H, s) ppm. Anal. calcd for C27H22IN5O3:
C, 54.82; H, 3.72; N, 11.84. Found: C, 54.67; H,3.56; N,
12.12.
2-Hydrozinoacetylmethylene-3-(indol-30yl)-6-iodo-4(3H)-
quinazolinone(4b). Mp 260–261 ꢀC (methanol/water); IR
(Nujol) n 3355, 3270, 3052, 2965, 1712, 1600, 1585,
1
760 cmÀ1; H NMR (DMSO-d6) d 8.60–7.95 (8H, m),
9.12 (1H, s), 4.12 (2H, s), 3.95 (2H, d), 5.86–5.70 (3H,
m) ppm. Anal. calcd for C19H16 IN5O2: C, 48.20; H,
3.38; N, 14.79. Found: C, 48.12; H, 3.72; N, 15.05.
2-(p-Methoxyphenylmethyleneimino)aminoacetylmethyl-
ene-3-(indol-30-yl)-6-iodo-4(3H)-quinazolinone (5f). Mp
197–198 ꢀC (ethylacetate); IR (KBr) n 3275, 1605, 1710,
2-Hydrozinoacetylmethylene - 3 - (20 - methylindol - 30yl)-6-
bromo-4(3H)-quinazolinone (4c). Mp 255–256 ꢀC (etha-
1205, 1600, 750 cmÀ1; H NMR (CDCl3) d 8.50–7.76
1
(12H, m), 9.20 (1H, s), 4.20 (2H, s), 3.91 (2H, d), 5.65 (1H,
t), 6.15 (1H, s). Anal. calcd for C26H19ClIN5O2: C,
60.21; H, 4.30; N,12.54. Found: C, 59.00; H, 4.12; N, 12.66.
nol); IR (KBr) n 3272, 3360, 1715, 1600, 1200, 560 cmÀ1
;
1H NMR (DMSO-d6) d 8.60–8.00 (7H, m), 9.15 (1H, s),
2.15 (3H, s), 4.11 (2H, s), 3.95 (2H, d), 5.80–5.65 (3H,
m) ppm. Anal. calcd for C20H18O2N5Br: C, 54.55; H,
4.09; N, 15.90. Found: 54.63; H, 4.17; N, 15.60.
2-(p-Methoxyphenylmethyleneimino)aminoacetylmethyl-
ene-3-(20 -methyl-indol-30 -yl)-6-bromo-4(3H)-quinazoli-
none (5g). Mp 221–222 ꢀC (ethanol/water); IR (KBr) n
2-(o-Methoxyphenylmethyleneimino)aminoacetylmethyl-
ene-3-(20-methyl-indol-30-yl)-4(3H)-qinazolinone (5a). A
mixture of compound 3a and o-methoxybenzaldehyde
in absolute methanol (50 mL) was refluxed for 8 h in
presence of glacial acetic acid (5 mL). The excess of
solvent was distilled off and the residue thus obtained
washed with a mixture of diethyl ether and water 6:8
and finally recrstallised from benzene/hexane to furnish
compound 5a (60%) mp 215–216 ꢀC. IR (KBr) n 3270,
3270, 3080, 2860, 2950, 1700, 1590, 1480 cmÀ1 1H
;
NMR (CDCl3) d 8.55–7.80 (1H, m) 9.22 (1H, s), 4.25
(2H, s), 3.95 (2H, d), 5.60 (1H, t), 6.18 (1H, s), 2.25 (3H,
s) ppm. Anal. calcd for C28H24BrN5O3: C, 60.21; H,
4.30; N, 12.54. Found: C, 59.90; H, 4.12; N, 12.66.
2 - (p - Dimethylaminophenylmethyleneimino)aminoacetyl-
methylene-3-(20-methyl-indol-30-yl)-6-bromo-4(3H)-quina-
zolinone (5h). Mp 211–212 ꢀC (methanol/water), n 1603,
3055, 2950, 1710, 605 cmÀ1
;
1H NMR (DMSO-d6) d
1210, 2962, 560 cmÀ1; H NMR (CDCl3) d 8.60–7.90
1
8.50–7.70 (12H, m) 9.10 (1H, s), 2.18 (3H, s), 4.15 (2H,
s), 3.90 (2H, s), 5.60 (1H, t), 6.10 (1, s), 3.15 (3H, s)
ppm. Anal. calcd for C28H25 N5O3: C, 70.14; H, 5.21, N,
14.61. Found: C, 70.55; H, 5.63; N, 14.25. The following
compounds were prepared using a similar procedure
described for 5a.
(11H, m), 9.20 (1H, s), 4.25 (2H, s), 3.95 (2H, d), 5.70
(1H, t), 6.20 (1H, s), 2.95 (6H, s), 2.25 (3H, s) ppm.
Anal. calcd for C28H27BrN6O2: C, 60.10, H, 4.83; N,
15.02. Found: C, 60.44; H, 4.69; N, 15.09.
2-(o-Chlorophenylmethyleneimino)aminoacetylmethylene
-3-(20 -methyl-indol-30 -yl)-6-bromo-4(3H)-quinazolinone
(5i). Mp 235–236 ꢀC (benzene), IR (KBr) n 3278, 1715,
2-(p-Methoxyphenylmethyleneimino)aminoacetylmethyl-
ene-3-(20-methyl-indol-30-yl)-4(3H)-quinazolinone
1
(5b).
Mp 195–196 ꢀC (ethanol); IR (KBr) n 3265, 3060, 2965,
1600, 1585, 1205, 562 cmÀ1; H NMR (CDCl3) d 8.65–
7.90 (11H, m), 9.22 (1H, s), 4.25 (2H, s), 3.90 (2H, d),

A. Kumar et al. / Bioorg. Med. Chem. 11 (2003) 5293–5299
5297
5.58 (1H, t), 6.25 (1H, s), 2.22 (3H, s) ppm. Anal. calcd
for C27H21BrN5O2Cl: C, 57.60; H, 3.73; N, 12.44.
Found: C, 57.37; H, 3.26; N, 12.80.
212–213 ꢀC (DMF/water); IR (Nujol) n 3280, 3028,
2825, 1710, 1603, 1580, 1220, 1012, 1108 cmÀ1 1H
NMR (CDCl3) d 8.60–7.20 (13H, m), 5.55 (1H, t), 4.80
(2H, s), 3.80 (2H, d), 4.21 (2H, s), 9.15 (1H, s), 6.20 (1H,
s) ppm. Anal. calcd for C28N21O3N5ClIS: C, 50.18; H,
3.13; N,10.45; Found: C, 50.22; H, 3.22; N, 10.48.
;
2-(o-Methoxyphenylaminomethylacetyl-40-oxo-10-thiazol-
idinyl)-3-(indol-300-yl)-4(3H)-quinazolinone (6a). Equi-
molar amount of compound 4a and thioglycolic acid in
absolute ethanol was refluxed for 18 h. The solvent was
removed under reduced pressure. The solid thus
obtained was treated with saturated solution of
NaHCO3 and then extracted three times with chloro-
form. The organic extract was combined, washed with
water, dried over anhydrous sodium sulphate, con-
centrated in vacuo upto a small volume and then chro-
matographed. The product finally obtained was
recrystallised from ethanol to give 6a (40%), mp 245–
246 ꢀC. IR (KBr) n 3272, 3075, 2860, 2955, 1710, 1580,
2-(p-Methoxyphenylaminomethylacetyl-40-oxo-10-thiazol-
idinyl)-3-(200-methyl-indol-300-yl)-6-bomo-4(3H)-quinazoli-
none (6g). Mp 214–215 ꢀC (ethanol/water) IR (KBr) n
3280, 3028, 2825, 1710, 1603, 1580, 1220, 1012 cmÀ1; 1H
NMR (CDCl3) d 8.60–7.20 (11H, m), 5.55 (1H, t), 4.80
(2H, s), 3.80 (2H, d), 4.21 (2H, s), 9.15 (1H, s), 6.20 (1H,
s), 3.21 (3H, s) ppm. Anal. calcd for C30H26BrN5O4S: C,
56.96; H, 4.11; N, 11.08. Found: C, 57.12; H, 4.36; N,
11.38.
1460 cmÀ1
;
1H NMR (CDCl3) d 8.55–7.70 (12H, m),
2-(p-Dimethylaminophenylaminomethylacetyl - 40oxo - 10 -
thiazolidinyl) - 3 - (200 - methyl-indol-30-yl)-6-bromo-4(3H)-
quinazolinone (6h). Mp 224–225 ꢀC (benzene); IR
(Nujol) n 3280, 3028, 2825, 1710, 1603, 1580, 1220,
9.12 (1H, s), 4.20 (2H, s), 3.85 (2H, d), 5.55 (1H, t), 4.80
(2H, s), 2.18 (3H, s), 3.20 (3H, s), 6.15 (1H, s) ppm.
Anal. calcd for C30H27N5O4S: C, 65.09; H, 4.88; N,
12.66. Found: C, 65.37; H, 4.66; N, 12.95.
1
1012, 1108 cmÀ1; H NMR (CDCl3) d 8.60–7.20 (11H,
m), 5.55 (1H, t), 4.80 (2H, s), 3.80 (2H, d), 4.21 (2H, s),
9.15 (1H, s), 6.20 (1H, s), 3.21 (3H, s), 2.90 (6H, s) ppm.
Anal. calcd for C31H29O3N6BrS; C, 57.67; H, 4.50; N,
13.02. Found: C, 57.93 ; H, 4.53; N, 13.31.
2-(p-Methoxyphenylaminomethylacetyl-40-oxo-10-thiazol-
idinyl) - 3 - (200methyl - indol - 300 - yl)-4(3H)-quinazolinone
(6b). Mp 255–256 ꢀC (methanol–water): IR (Nujol) n
1
3275, 3025, 2950, 1710, 1450 cmÀ1; H NMR (DMSO-
d6) d 8.55–7.22 (12H, m), 9.15 (1H, s), 4.20 (2H, s), 3.85
(2H, d), 5.56 (1H, t), 4.80 (2H, s), 2.18 (3H, s), 3.20 (3H,
s), 6.20 (1H, s) ppm. Anal. calcd for C30H27N5O4S: C,
65.09; H, 4.88; N, 12.66. Found: C, 65.40; H, 5.11; N,
12.87.
2-(o-Chlorophenylaminomethylacetyl-40-oxo-10-thiazolidi-
nyl)-3-(200-methyl-indol-300-yl)-6-bromo-4(3H)-quinazoli-
none (6i). Mp 255–256 ꢀC (methanol/water); IR (KBr) n
3280, 3028, 2825, 1710, 1603, 1580, 1220, 1012,
1108 cmÀ1 1H NMR (CDCl3) d 8.60–7.20 (11H, m),
;
5.55 (1H, t), 4.80 (2H, s), 3.80 (2H, d), 4.21 (2H, s), 9.15
(1H, s), 6.20 (1H, s), 3.21 (3H, s) ppm. Anal. calcd for
C29H23BrClN5O3S: C, 54.76; H, 3.61; N, 11.00. Found:
C, 54.93; H, 3.63; N, 11.26.
2-(o-Chlorophenylaminomethylacetyl-40-oxo-10-thiazolidi-
nyl)-3-(200methyl-indol-300-yl)-4(3H)-quinazolinone (6c).
Mp 218–220 ꢀC (benzene): IR (KBr) n 3280, 3025,
1
2830, 1710, 1603, 1575, 1220, 2010 cmÀ1; H NMR d
8.52–7.22 (12H, m), 9.15 (1H, s), 3.20 (3H, s), 3.82 (2H,
d), 4.20 (2H, s), 5.55 (1H, d), 6.20 (1H, s) 4.80 (2H, s)
ppm. Anal. calcd for C29H24O3N5ClS, C, 62.42; H, 4.30;
N, 12.56.00 Found: C, 62.65; H, 4.39; N, 12.67.
Pharmacological evaluation
Male albino rats and mice of Charles Foster strain
species were used in experiments. The animals were kept
in the groups (control, treated, standard) under con-
stant temperature (25Æ1 ꢀC) and 12-h light/dark cycle.
They had free access to standard mouse diet and tap
water except during the experiment. On the day of
the experiment, animals were transferred to individual
cages randomly and allowed to acclimatize for 30 min
before drug administration. Indomethacin and
phenylbutazone were used as standard drugs. Newly
synthesized compounds were dissolved in propylene-
glycol.
2-(o-Methoxyphenylaminomethylacetyl-40-oxo-10-thiazol-
idinyl)-3-(indol-300-yl)-6-iodo-4(3H)-quinazolinone (6d).
Mp 200–201 ꢀC (benzene); IR (KBr) n 3280, 3028, 2825,
1
1710, 1603, 1580, 1220, 1012 cmÀ1; H NMR (DMSO-
d6) d 8.60–7.20 (12H, m), 4.21 (2H, s), 5.55 (1H, t), 3.80
(2H, d), 4.81 (2H, s), 9.15 (1H, s), 2.20 (3H, s), 6.20 (1H,
s) ppm. Anal. calcd for C29H24N5O4IS: C, 52.33, H,
3.61; N, 10.53. Found: C, 52.21; H, 3.56; N, 10.63.
2-(p-Methoxyphenylaminomethylacetyl-40-oxo-10-thiazol-
idinyl)-3-(indol-300-yl)-6-iodo-4(3H)-quinazolinone (6e).
Mp 250–251 ꢀC (benzene); IR (Nujol) n 3280, 3028,
Anti-inflammatory activity
2825, 1710, 1603, 1580, 1220, 1012, 1108 cmÀ1
;
1H
Paw oedema inhibition test was performed on albino
rats by adopting the method of Winter et al.14 Thirty
min later, 0.2 mL of 1% carrageenan suspension in
0.9% NaCl solution was injected subcutaneously into
the plantar aponeurosis of the hind paw, and the paw
volume was measured by a water plethysmometer socrel
and then measured again 3 h later. The mean increase of
paw volume at each time interval was compared with
that of control group at the same time intervals and
NMR (DMSO-d6) d 8.60–7.20 (12H, m), 5.55 (1H, t),
4.80 (2H, s), 3.80 (2H, d), 4.21 (2H, s), 9.15 (1H, s), 2.22
(3H, s), 6.20 (1H, s) ppm. Anal. calcd for
C29H24O4N5IS: C, 52.33; H, 3.61; N, 10.53. Found: C,
52.52; H, 3.66; N, 10.71.
2-(p-Chlorophenylaminomethylacetyl-40-oxo-10-thiazolidi-
nyl)-3-(indol-300-yl)-6-iodo-4(3H)-quinazolinone (6f). Mp

5298
A. Kumar et al. / Bioorg. Med. Chem. 11 (2003) 5293–5299
percent inhibition values were calculated by the formula
given below:
amount of [1-14C] arachidonic acid [ ffi 200 (xx) cpm]
was then added and the reaction proceeded for 3 min at
37 ꢀC. The reaction was stopped by addition of 0.2 mL
of ethyl ether/methanol/citric acid 0.2 M (30:4:1), which
was precooled at À25 ꢀC PGE2, was extracted twice into
the same mixture. The solvent was evaporated under an
N2 stream and radiolabelled arachidonic acid was sepa-
rated from radiolabelled acid was separated from radio-
labelled PGE3 by RP-HBLC. HPLC analysis was
performed on a Hitachi spectrophotometer equipped
with a flow cell. The sample was injected on an ultra-
sphere column (Beckman) ODS 5 mm. 4.6 mmꢁ25 cm
with 2 nmol unlabelled PGE2 as an interval standard,
PG chromatographic profile was obtained by isocratic
elution with 150 mM H3PO4 in water, pH 3.5, contain-
ing 30% acetonitrile, a flow rate of 1 mL/min monitor-
ing the uvabsorption at 214 nm. Radioactivity that co-
eluted with autheutic PGE2 was quantified by liquid
scintillation spectrometry. Test samples were compared
to paired control incubations. The percentage of inhibi-
tion was calculated as follows:
% anti-inflammatory activity ¼ 1 À ðVt=VcÞ Â 100
where Vt and Vc are tested and control groups, respec-
tively.
Analgesic activity
Acetic acid writhing test was performed on mice by fol-
lowing the method of Davis et al.15 Test compounds
were given to the animals at a dose of 50 mg/kg, 30 min
later the animals were injected intraperitoneally with
0.25 mL/mouse of 0.5% acetic acid. The mean number
of writhes for each experimental groups and percentage
decrease compared with the control group were calcu-
lated after 60 min.
Ulcerogenic activity
Ulcerogenic liabilities of newly synthesized compounds
was checked by the method of Verma et al.16 Albino
rats were fasted for 24 h prior to drug administration.
All animals were sacrificed 8 h after drug treatment, and
then their stomachs and small intestines were micro-
scopically examined to assess the incidence of hyper-
aemia, shedding of epithelium, petechial and frank
haemorrhages and erosion or discrete ulceration with or
without perforation. The presence of any one of these
criteria was considered to be an evidence of ulcerogenic
activity.
½ðcpm control À cpm test=ðcpm controlÞ Â 100Š
Acknowledgements
We are thankful to CDRI, Lucknow (U.P), India for
elemental analysis and spectral analysis. One of author
(Shalabh Sharma) is also thankful to CSIR, New Delhi
for the award of SRF.
References and Notes
Acute toxicity study
Approximate lethal dose (ALD50) of compounds was
determined in albino mice. The test compounds were
given orally at different dose levels in groups of 10 ani-
mals. After 24 h of drug administration, percent mor-
tality in each group was observed and from the data
obtained ALD50 was calculated by the method of
Smith.17
1. Roberts, L. J., II; Morrow, J. D. Goodman & Gilman’s The
Pharmacological Basis of Therapeutics; McGraw Hill: New
York, 2001; p. 687.
2. Bansal, E.; Ram, T.; Sharma, S.; Tyagi, M.; Archana;
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Cyclooxygenase activity
This test was carried out in vitro according to reported
method18 on the microsomal fraction of mucosal pre-
parations of rabbit distal colon in order to search out
the possible mechanism of the compounds. Colonic
mucosa ( ffi 2–3 g), stripped as previously described was
minced and homogenized Potter homogenizer in 3 vol of
Tris buffer 0.1, pH 8.0. The homogenate was centrifused
for 30 min at 10,000 g. The resulting supernatent was
centrifused for 1 h at 100,000 g. The precipitate was
suspended in Tris buffer 0.1 M, pH 8.0, and recen-
trifused for 1 h at 100,000 g. The microsomal pellet was
used immediately for enzyme assay cyclooxygenase
activity was assayed by measuring the rate of conver-
sion of arachidonic acid to PGE2. Microsomal fractions
(50 mL) were incubated with test agents for 5 min at
37 ꢀC in 30 mL Tris–HCl, pH 8.0 containing 2 mM
reduced glutathione, 5 mM l-tryptophan, 1 mM hema-
tin. The substrate 20 mM arachidonic acid with tracer
14. Winter, C. A.; Risley, E. A.; Nuss, G. W. Proc. Soc. Exp.
Biol. 1962, NY 111, 544.

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5299
15. Davis, J. E.; Kellet, D. N.; Penningtn, J. C. Arch. Int.
Pharma. Ther. 1976, 221, 274.
16. Verma, M.; Sinha, J. N.; Gujrati, V. R.; Bhalla, T. N.;
Bhargava, K. S.; Shanker, K. Pharmacol. Res. Conomum.
1981, 13, 967.
17. Smith, Q. E. Pharmacological Sereently Tests Progress in
Medicinal Chemistry; Butterworth: London, 1960; p. 16.
18. Calderano, V.; Parrillo, C.; Grovane, A. J. Pharmacol.
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