Synthesis of new substituted azetidinoyl and thiazolidinoyl-1,3,4-thiadiazino (6,5-b) indoles as promising anti-inflammatory agents

Article abstract of DOI:10.1016/j.ejmech.2007.10.012

Various N-({5-[(arylmethylene)amino]-1,3,4-thiadiazol-2-yl}methyl) [1,3,4] thiadiazino[6,5-b]indol-3-amine (6a-6h), 2-aryl-3-{5-[([1,3,4] thiadiazino[6,5-b]indol-3-ylamino)methyl]-1,3,4-thiadiazol-2-yl}-1,3-thiazolidin-4-one (7a-7h), and 3-chloro-4-aryl-1-{5-[{[1,3,4]thiadiazino[6,5-b]indol-3-ylamino]methyl]-1,3,4-thiadiazol-2-yl}azetidin-2-one (8a-8h) have been synthesized in the present study. The structure of these newly synthesized compounds were confirmed by their analytical and spectral data. These compounds were also evaluated for their anti-inflammatory, ulcerogenic and analgesic activities. Compound 8g has shown most active anti-inflammatory and analgesic activities with better ulcerogenic activity than phenylbutazone, while this compound was found to be associated with lesser degree of anti-inflammatory and analgesic activities as compared to indomethacin.

Full text of DOI:10.1016/j.ejmech.2007.10.012

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European Journal of Medicinal Chemistry 43 (2008) 2323e2330
http://www.elsevier.com/locate/ejmech
Original article
Synthesis of new substituted azetidinoyl and thiazolidinoyl-1,3,
4-thiadiazino (6,5-b) indoles as promising anti-inflammatory agents
1
Sudhir Kumar Bhati , Ashok Kumar
*
Department of Pharmacology, L.L.R.M. Medical College, Gargh Road, Meerut 250004 (UP), India
Received 24 April 2007; received in revised form 3 October 2007; accepted 4 October 2007
Available online 18 October 2007
Abstract
Various N-({5-[(arylmethylene)amino]-1,3,4-thiadiazol-2-yl}methyl) [1,3,4] thiadiazino[6,5-b]indol-3-amine (6ae6h), 2-aryl-3-{5-[([1,3,4]
thiadiazino[6,5-b]indol-3-ylamino)methyl]-1,3,4-thiadiazol-2-yl}-1,3-thiazolidin-4-one (7ae7h), and 3-chloro-4-aryl-1-{5-[{[1,3,4]thiadia-
zino[6,5-b]indol-3-ylamino]methyl]-1,3,4-thiadiazol-2-yl}azetidin-2-one (8ae8h) have been synthesized in the present study. The structure
of these newly synthesized compounds were confirmed by their analytical and spectral data. These compounds were also evaluated for their
anti-inflammatory, ulcerogenic and analgesic activities. Compound 8g has shown most active anti-inflammatory and analgesic activities with
better ulcerogenic activity than phenylbutazone, while this compound was found to be associated with lesser degree of anti-inflammatory
and analgesic activities as compared to indomethacin.
Ó 2007 Elsevier Masson SAS. All rights reserved.
Keywords: Benzylidenaminoindoles; Thiazolidinones; Azetidinones; Anti-inflammatory, analgesic, ulcerogenic activities and toxicity studies
1. Introduction
compounds have been screened for their anti-inflammatory,
ulcerogenic, analgesic and toxicity activities.
Acute and chronic inflammation and different type of ar-
thritis are the inflammatory disorders, which are a big blow
to humanity and continual search for newer non-steriodal
anti-inflammatory agents is the only way to fortify against
this awful threat. Indole and its analogs constitute the active
class of compounds possessing wide spectrum of biological
activities, such as anti-inflammatory [1-6], anticonvulsant
[7], antimicrobial [8] antibacterial [9,10] antifungal [11,12],
Moreover, azetidinones [13,14] and thiazolidinones [15,16]
are well famed for their anti-inflammatory activities. In the
light of above report and also in continuation of our laboratory
work on chemoselective reaction of indole derivatives, a drug
strategy has been planned to synthesize several indole deriva-
tives possessing azetidinone and thiazolidinone moiety with
the hope to get better anti-inflammatory molecules. All
2. Chemistry
The chemical synthesis initiates with the reaction of indole-
2,3-dione with thiosemicarbazide to yield 3-thiosemicarbazi-
doindole-2-one 1. 2-Amino-1,3,4-thiadiazino (6,5-b) indole-2
was prepared by the cyclization of compound 1 with cold
conc. sulphuric acid. Furthermore, compound 2 reacted with
chloroethylacetate to yield 2-carboethoxymethylamino-
1,3,4,-thiadiazino(6,5-b) indole 3. The latter compound on
reaction with thiosemicarbazide resulted into the formation
of 2-(thiosemicarbazidocarbonylmethylamino)-1,3,4,-thiadia-
zino(6,5-b) indole 4. Compound 4 on treatment with conc.
H2SO4 and followed by neutralization with liquid NH3 gave
2-[50-aminothiadiazol-20-yl methylamino]-1,3,4-thiadiazino
(6,5-b) indole 5. Compound 5 when reacted with substituted
benzaldehydes yielded N-({5-[(arylmethylene)amino]-1,3,4-
thiadiazol-2-yl}methyl)[1,3,4] thiadiazino(6,5-b)indol-3-amine
6ae6h, 2-aryl-3-{5-[([1,3,4] thiadiazino(6,5-b)indol-3-ylamino)
* Corresponding author. Tel.: þ91 121 2764084, mobile: þ91 9917053074.
E-mail address: rajputak@gmail.com (A. Kumar).
1
Part of the thesis work of Sudhir Kumar Bhati.
0223-5234/$ - see front matter Ó 2007 Elsevier Masson SAS. All rights reserved.
doi:10.1016/j.ejmech.2007.10.012

2324
S.K. Bhati, A. Kumar / European Journal of Medicinal Chemistry 43 (2008) 2323e2330
methyl]-1,3,4-thiadiazol-2-yl}-1,3-thiazolidin-4-one 7ae7h, were
synthesized by cyclo condensation of 6ae6h with thioglycolic acid
in the presence of anhydrous ZnCl2, while 3-chloro-4-aryl-1-
{5-[{[1,3,4]thiadiazino(6,5-b)indol-3-ylamino]methyl]-1,3,4-
thiadiazol-2-yl}azetidin-2-one 8ae8h were synthesized by
cycloaddition of 6ae6h with chloroacetylchloride in presence
of triethylamine. The structure of all newly synthesized indole
derivatives were confirmed on the basis of analytical and
spectral data (Scheme 1).
Moreover, rest of the compounds showed moderate degree
of COX-1 and COX-2 inhibitory actions suggesting that these
compounds showed anti-inhibitory activity by inhibition of
both COX-1 and COX-2 enzymes.
ALD50 of all these compounds were >800 mg/kg p.o.
4. Conclusion
1. Azetidinones 8ae8h possessed more potent anti-inflamma-
tory and analgesic activities than that of their corresponding
parent compounds, i.e. N-({5-[(arylmethylene)amino]-
1,3,4-thiadiazol-2-yl}methyl) [1,3,4] thiadiazino(6,5-b)in-
dol-3-amine 6ae6h.
3. Results and discussion
All the newly synthesized compounds of this series were
tested for anti-inflammatory, analgesic, and ulcerogenic activi-
ties, at a dose of 50 mg/kg p.o. The results of anti-inflammatory
and analgesic activities of all the compounds are statistically sig-
nificant (Table 4). Out of 20 compounds, only three compounds
7g, 8g and 8h were found to possess more potent anti-inflamma-
tory activity in comparison to phenylbutazone. Compound 7g,
which was substituted with chloro group at 2 position of phenyl
ring have shown 38.54% of inhibition of oedema. Compound 6a
which possessed phenyl ring have shown least activity, i.e.
14.75%. Compound 7c which was substituted with 4-methoxy
group on phenyl ring, has shown moderate degree of anti-in-
flammatory activity (28.13%).
2. Azetidinone compounds 8ae8h have also shown better ac-
tivities then thiazolidinones 7ae7h.
3. Compounds 7g and 8g having a 2-chlorophenyl group as
substituent exhibited most potent anti-inflammatory and
analgesic activities. Thus the obtained biological results
clearly indicate that compounds which showed maximum
anti-inflammatory activity also exhibit potent analgesic
activity.
4. All the compounds 6ae6h, 7ae7h and 8ae8h have shown
much less anti-inflammatory and analgesic activities,
when compared with indomethacin.
The last step compounds 8ae8h were characterized by the
presence of an azetidinone ring (b-lactam). All the compounds
of this stage have shown promising degree (30.55e41.23%) of
anti-inflammatory activity. Compound 8g, has shown the max-
imum percentage of anti-inflammatory activity, i.e. 41.23% at
a dose of 50 mg/kg p.o. Considering, the potentiality of com-
pounds 7g and 8g, these were studied in detail at three graded
doses 25, 50, 100 mg/kg p.o. Compound 8g exhibited better
anti-inflammatory activity at all three graded doses of 25, 50
and 100 mg/kg p.o. as compared to phenylbutazone. However,
compound 8g was less active as compared to indomethacin at
the three graded doses. The ulcerogenic liabilities of com-
pounds 7g (166.66 mg/kg i.p.) and 8g (133.33 mg/kg i.p.)
are much less than that of indomethacin (54.60 mg/kg i.p.)
and phenylbutazone (66.6 mg/kg i.p.). The azetidinone deriv-
atives 8ae8h showed better analgesic activity than thiazolidi-
nones 7ae7h. Compounds of thiazolidinones 7ae7h have
shown moderate to good analgesic activity. Compound 7g
which was substituted by 2-chlorophenyl ring at 5-position
of thiadiazole nucleus exhibited most potent (24.67%) analge-
sic activity at 50 mg/kg p.o. The most active compound of this
series was 8g which has shown potent analgesic activity, i.e.
38.00% at a dose of 50 mg/kg p.o. Moreever, when these com-
pounds were tested at three (25, 50 and 100) graded doses, it
was found that analgesic activity of 7g was less than phenyl-
butazone and indomethacin while 8g exhibited better analge-
sic activity than phenylbutazone, while it is less active then
indomethacin.
5. Experimental
5.1. Chemistry
The melting points of the compounds were determined in
open glass capillaries with the help of thermonic melting
points apparatus and are uncorrected. The homogeneity of
all the newly synthesized compounds were routinely checked
by TLC on silica gel G plates and spots were located by using
iodine chamber. Elemental analysis was performed in Heraeus
CHN rapid analyser. The results were found within the ꢀ0.4%
of theoretical values. Infrared spectra were recorded on KBr
pellets on a PerkineElmer system 2000 FTIR spectrometer
and 1H NMR spectra on Bruker DPX 200 using TMS as inter-
nal standard and chemical shifts expressed in d ppm.
Compounds 1 and 2 were synthesized according to the
method of Panwar et al. [17].
5.1.1. 3-Thiosemicarbazido indole-2-one [1]
A mixture of indole-2,3-dione (0.01 mol), thiosemicarba-
zide (0.01 mol) in methanol (50 ml) was refluxed for 1 h.
The completion of reaction was checked by TLC and excess
of methanol was distilled off. The cooled reaction mixture
was poured into ice-water, filtered, washed with water, dried
and recrystallized from methanol to obtain compound 1
(80%), m.p. 205 ꢁC.
IR (KBr) nmax in cmꢂ1: 1205 (C]S), 1615 (C]C of aro-
matic ring), 1665 (C]N), 1715 (C]O), 3140 (CeH aro-
All these compounds were also evaluated for COX-1 and
COX-2 inhibitory activities. Compound 7g showed 43.13%
COX-1 and 74.64% COX-2 inhibition action while compound
8g exhibited 69.13% and 93.34% inhibition of action.
1
matic), 3420 (NH2). H NMR (CDCl3) d in ppm: 6.70e6.90
(d, 1H, ArH), 7.10e7.15 (t, 1H, ArH), 7.25e7.30 (t, 1H,
ArH), 7.55e7.60 (d, 1H, ArH), 9.42 (bs, 1H, NH indolic),

S.K. Bhati, A. Kumar / European Journal of Medicinal Chemistry 43 (2008) 2323e2330
2325
2
Scheme 1.
7.75 (bs, 1H, NH), 8.90 (bs, 2H, NH2). Anal. Calcd for
C9H8N4SO: C, 49.09; H, 3.63; N, 25.45; Found C, 49.32; H,
3.64; N, 25.56%. MS: [M]þ at m/z 220.
temperature for 16 h. The reaction mixture was poured into
ice-cold water, neutralized with liquid ammonia to obtain solid
mass, which was filtered, washed with water, dried and recrys-
tallized from methanol to yield compound 2 (70%), m.p.
235 ꢁC. IR (KBr) nmax in cmꢂ1: 670 (CeSeC), 1290 (NeN),
1615 (C]C of aromatic ring), 1585 (C]N), 3140 (CeH aro-
5.1.2. 2-Amino-1,3,4-thiadiazino (6,5-b) indole [2]
Compound 1 (0.01 mol) was mixed with cold and conc.
H2SO4 (0.001 mmol). The reaction mixture was left at room
1
matic), 3415 (NH2). H NMR (CDCl3) d in ppm: 6.85e6.90

2326
S.K. Bhati, A. Kumar / European Journal of Medicinal Chemistry 43 (2008) 2323e2330
(d, 1H, ArH), 7.05e7.10 (t, 1H, ArH), 7.25e7.30 (t, 1H, ArH),
7.55e7.60 (d, 1H, ArH), 8.55 (bs, 2H, NH2). Anal. Calcd for
C9H6N4S: C, 53.46; H, 2.98; N, 27.73; Found: C, 53.52; H,
2.97; N, 27.77. MS: [M]þ at m/z 202.
5.1.5. 2-(50-amino 1,3,4-thiadiazol-20-yl methylamino)-
1,3,4-thiadiazino (6,5-b) indole [5]
A mixture of compound 4 (0.01 mol) and conc. H2SO4
(20 ml) was kept overnight at room temperature, poured into
ice-cold water, neutralized with liquid ammonia and filtered.
The product thus obtained was recrystallized from ethanol wa-
ter to furnish compound 5 (60%), m.p. 256 ꢁC.
5.1.3. 2-Carboethoxymethylamino 1,3,4, thiadiazino
(6,5-b) indole [3]
IR (KBr) nmax in cmꢂ1: 3370 (NH2), 2960 (CeH aliphatic),
1584 (C]C of aromatic ring), 2970 (CeH aromatic), 3170
(NH), 1572 (C]N), 1235 (CeN), 1290 (NeN), 738 (CeSe
A
mixture of compound 2 and chloroethylacetate
(0.01 mol) in dry dioxane (50 ml) was refluxed for 8 h. The re-
action mixture was further stirred for 1 h, and poured in water.
The resulting mixture was filtered and recrystallized from eth-
anol to yield compound 3 (68%), m.p. 222 ꢁC.
1
C). H NMR (CDCl3) d in ppm: 7.05e7.30 (m, 4H, Ar-H),
6.26 (bs, 2H, NH2), 4.55 (d, 2H, NHeCH2), 5.75 (t, 1H,
NH, exchangeable with D2O). Anal. Calcd for C12H9N7S2:
C, 50.89; H, 3.18; N, 34.63; Found: C, 50.97; H, 3.15; N,
34.68. MS: [M]þ at m/z 315.
IR (KBr) nmax in cmꢂ1: 1572 (C]N), 728 (CeSeC), 1695
(C]O), 2950 (CeH aliphatic), 3045 (CeH aromatic), 1295
1
(NeN), 3185 (NeH), 1245 (CeN). H NMR (CDCl3) d in
ppm: 6.95e7.15 (m, 4H, Ar-H), 1.45 (t, 3H, COOCH2e
CH3), 4.25 (q, 2H-COOCH2eCH3), 4.55 (d, 2H, NHeCH2),
6.10 (t, 1H, NH, exchangeable with D2O). Anal. Calcd for
C13H12N4O2S: C, 54.16; H, 4.16; N, 19.44; Found: C, 54.12;
H, 4.18; N, 19.43. MS: [M]þ at m/z 288.
5.1.6. N-({5-[(arylmethylene)amino]-1,3,4-thiadiazol-2-
yl}methyl) [1,3,4] thiadiazino(6,5-b)indol-3-amine
[6ae6h]
A mixture of compound 5 (0.01 mol) and proper aromatic al-
dehydes (0.01 mol) in methanol (50 ml) was refluxed for 7 h, in
the presence offew drops of glacial acetic acid. The progress and
completion of reaction was checked by TLC. The reaction mix-
tures were distilled off cooled and then poured into ice water, fil-
tered, washed with water and dried. By this procedure,
compounds 6ae6h were obtained starting from benzaldehyde.
4-Chlorobenzaldehyde, 4-methoxybenzaldehyde, 4-hydroxy-
benzaldehyde, 4-N-dimethylbenzaldehyde, 4-methylbenzalde-
5.1.4. 2-(Thiosemicarbazido carbonylmethylamino)-1,3,
4-thiadiazino (6,5-b) indole [4]
The equimolar mixture (0.02 mol) of compound 3 and thi-
osemicarbazide (0.02 mol) in methanol (50 ml) was refluxed
for 10 h. The excess of solvent was distilled off and viscous
mass was poured into water, dried and recrystallized from
methanol to yield compound 4 (64%), m.p. 229 ꢁC.
IR (KBr) nmax in cmꢂ1: 1575 (C]N), 722 (CeSeC), 1250
(CeN), 3182 (NeH), 3188 (CeH aromatic), 1705 (C]O),
hyde,
2-chlorobenzaldehyde,
2-methoxybenzaldehyde,
respectively. The solid thus obtained was recrystallized from ap-
propriate solvent to yield compounds 6ae6h. Their physical,
analytical and spectral data are given in Tables 1 and 5.
1
2975 (CeH aliphatic), 1590 (C]C aromatic ring). HNMR
(CDCl3) d in ppm: 6.92e7.22 (m, 4H, Ar-H), 7.32e8.12 (m,
4H, NHNHCSNH2, exchangeable with D2O), 4.47 (d, 2H,
NHeCH2), 5.60 (t, 1H, NH, exchangeable with D2O). Anal.
Calcd for C12H11N7OS2: C, 43.24; H, 3.30; N, 29.42; Found:
C, 43.32; H, 3.32; N, 29.47. MS: [M]þ at m/z 333.
5.1.7. 2-aryl-3-{5-[([1,3,4] thiadiazino(6,5-b)indol-3-
ylamino)methyl]-1,3,4-thiadiazol-2-yl}-1,3-thiazolidin-4-
one [7ae7h]
To a solution of compounds 6ae6h in methanol (50 ml),
thioglycolic acid (0.02 mol) was added dropwise in the
Table 1
Physical and analytical data of compounds 6ae6h
Compound No.
R
M.p. (ꢁC) Yield Recrystallization solvent Molecular formula Element analysis
%C
Calcd Found Calcd Found Calcd Found
%H
%N
6a
6b
6c
6d
6e
6f
C6H5
220
205
200
210
60
55
58
54
51
56
52
55
Methanolewater
Methanolewater
Ethanolewater
Methanolewater
DMFewater
C19H13N7S2
56.58 56.62
52.11 52.18
55.42 55.36
54.41 54.48
56.50 56.56
57.56 57.51
52.11 52.16
55.42 55.48
3.22
2.75
3.46
3.10
4.03
3.60
2.75
3.46
3.23
2.74
3.48
3.11
4.02
3.62
2.76
3.45
24.31 24.35
22.40 22.46
22.64 22.60
23.38 23.32
25.11 25.14
23.50 23.55
22.40 22.36
22.64 22.61
4-ClC6H4
4-OCH3C6H4
4-OHC6H4
C19H12Cl N7S2
C20H15N7OS2
C19H13N7OS2
C21H18N8S2
4- N(CH3)2C6H4 195
4-CH3C6H4
2-Cl C6H4
2-OCH3C6H4
190
195
180
Methanolewater
Methanolewater
Ethanolewater
C20H15 N7S2
C19H12Cl N7S2
C20H15N7OS2
6g
6h

S.K. Bhati, A. Kumar / European Journal of Medicinal Chemistry 43 (2008) 2323e2330
2327
Table 2
Physical and analytical data of compounds 7ae7h
Compound No.
R
M.p. (ꢁC) Yield Recrystallization solvent Molecular formula Element analysis
%C
%H
%N
Calcd Found Calcd Found Calcd Found
7a
7b
7c
7d
7e
7f
C6H5
175
165
160
170
50
45
48
42
46
44
41
45
Methanolewater
Methanolewater
Ethanolewater
Methanolewater
DMFewater
C21H15N7OS3
C21H14ClN7OS3
C22H17N7O2S3
C21H15N7O2S3
C23H20N8OS3
C22H17N7OS3
C21H14ClN7OS3
C22H17N7O2S3
52.83 52.96
50.26 50.32
52.07 52.15
51.11 51.18
51.49 51.41
54.77 54.82
50.26 50.32
52.07 52.02
3.14
2.74
3.35
3.04
3.74
3.46
2.74
3.35
3.15
2.75
3.37
3.05
3.75
3.45
2.75
3.37
20.55 20.61
19.15 19.20
19.32 19.38
19.87 19.82
20.90 20.96
19.96 19.92
19.15 19.19
19.32 19.37
4-ClC6H4
4-OCH3C6H4
4-OHC6H4
4- N(CH3)2C6H4 165
4-CH3C6H4
2-Cl C6H4
2-OCH3C6H4
160
155
150
Methanolewater
Methanolewater
Ethanolewater
7g
7h
presence of anhydrous zinc chloride and the reaction mixture
was refluxed for 10 h. The completion of the reaction was
checked by TLC. The excess of methanol was distilled off.
The cooled residual mass was diluted with ice-water, filtered,
washed with water, dried and recrystallized from suitable sol-
vents to yield compounds 7ae7h. Their physical, analytical
and spectral data are given in Tables 2 and 5.
washed with water, dried and recrystallized from suitable sol-
vents to yield compounds 8ae8h. Their physical, analytical
and spectral data are given in Tables 3 and 5.
5.2. Pharmacology
Compounds 6ae8h (Table 4) were tested for their anti-in-
flammatory and analgesic activities as well as for their ulcer-
ogenicity and acute toxicity. The experiment was performed
with albino rats of CharleseFoster strain of either sex, exclud-
ing pregnant females, of 60e90 days weighing 100e120 g.
Food (chaw pallet) and water was given to the animals ad li-
bitum. The test compounds were dissolved in propylene gly-
col. Indomethacin and phenylbutazone were used as
reference drugs for the comparison of anti-inflammatory, anal-
gesic and ulcerogenic activities.
5.1.8. 2-3-chloro-4-aryl-1-{5-[{[1,3,4]thiadiazino(6,5-b)
indol-3-ylamino]methyl]-1,3,4-thiadiazol-2-yl}azetidin-2-
one [8ae8h]
To the ethanolic solution of the synthesized 6ae6h
(0.01 mol) was added dropwise with constant stirring in pres-
ence of triethylamine (0.01 mol) at 0.5 ꢁC. The reaction mix-
ture was refluxed for 8 h. The completion of reaction was
checked by TLC and excess of ethanol distilled off. The result-
ing residual mass was cooled, poured into ice water, filtered,
Table 3
Physical and analytical data of compounds 8ae8h
Compound No.
R
M.p. (ꢁC) Yield Recrystallization solvent Molecular formula Element analysis
%C
Calcd Found Calcd Found Calcd Found
%H
%N
8a
8b
8c
8d
8e
8f
C6H5
165
155
160
150
40
35
32
38
36
31
34
35
Ethanolewater
Methanolewater
Methanolewater
Ethanolewater
DMFewater
C21H14ClN7OS2
C21H13Cl2N7OS2
C22H16ClN7O2S2
C21H14ClN7O2S2
C23H19ClN8OS2
C22H16ClN7OS2
C21H13Cl2N7OS2
C22H16ClN7O2S2
52.56 52.62
49.02 49.08
51.82 51.96
50.86 50.72
52.83 52.97
53.49 53.42
49.02 49.09
51.82 51.74
2.92 2.93
2.53 2.52
3.14 3.16
2.83 2.82
3.64 3.62
3.24 3.26
2.53 2.54
30.14 3.15
20.43 20.46
19.06 19.09
19.23 19.18
19.78 19.72
21.43 21.48
19.86 19.81
19.06 19.12
19.23 19.27
4-ClC6H4
4-OCH3C6H4
4-OHC6H4
4- N(CH3)2C6H4 155
4-CH3C6H4
2-Cl C6H4
2-OCH3C6H4
145
150
140
Methanolewater
Methanolewater
Ethanolewater
8g
8h

2328
S.K. Bhati, A. Kumar / European Journal of Medicinal Chemistry 43 (2008) 2323e2330
Table 4
Pharmacology data of compounds (6ae6h), (7ae7h) and (8ae8h)
Compound No.
R
Anti-inflammatory activity
Analgesic activity
UD50 (mg/kg/ip) IC50 % of inhibition ALD50(mg/kg/ip)
Dose (mg/kg/p.o) % Inhibition Dose
of oedema
% Protection
COX-1
COX-2
(mg/kg/p.o)
6a
6b
6c
6d
6e
6f
C6H5
50
50
50
50
14.75**
50
50
50
50
50
50
50
50
50
50
50
50
50
50
25
50
100
50
50
50
50
50
50
50
25
50
100
50
25
50
100
12.16**
16.50**
15.67**
16.87**
14.28**
12.67**
18.66**
22.23***
9.70*
e
22.37*
27.43*
26.16*
25.15*
24.25*
23.13*
28.67*
24.13*
31.89*
36.52**
34.28**
34.39**
32.22**
33.42**
43.13**
24.23*
33.67**
29.44*
31.47**
26.39*
25.40*
34.38**
26.67*
36.68**
>800
>800
>800
>800
>800
>800
>800
>800
>800
4-ClC6H4
4-OCH3C6H4
4-OHC6H4
25.97***
22.37**
24.32**
e
e
e
4- N(CH3)2C6H4 50
21.36**
20.66**
e
4-CH3C6H4
2-Cl C6H4
2-OCH3C6H4
C6H5
50
50
50
50
50
50
50
e
e
6g
6h
7a
7b
7c
7d
7e
7f
26.03***
23.16**
19.78**
e
e
4-ClC6H4
4-OCH3C6H4
4-OHC6H4
18.16**
8.78*
10.76**
9.95*
e
e
44.12*** >800
40.06*** >800
43.98*** >800
28.13***
25.27***
28.66***
36.97***
22.44***
38.54***
44.51***
31.34***
30.55***
34.67***
31.62***
32.67***
33.60***
32.17***
28.75***
41.23***
66.76***
36.19***
26.76***
36.80***
64.68**
e
4- N(CH3)2C6H4 50
18.00**
22.08***
12.32***
24.67***
36.36***
22.56***
21.00**
25.01***
21.27**
19.95**
22.67***
18.76**
19.00***
38.00***
58.00***
35.00***
14.26***
32.50***
54.58***
41.30***
59.25***
64.33***
e
e
166.66
38.14**
36.32**
45.35*** >800
>800
>800
4-CH3C6H4
2-C1 C6H4
50
25
7g
50
100
50
7h
8a
8b
8c
8d
8e
8f
2-OCH3C6H4
C6H5
e
33.34**
38.54**
>800
50
50
e
37.05*** 74.64*** >800
40.94*** 72.14*** >800
39.53*** 66.26*** >800
4-ClC6H4
4-OCH3C6H4
4-OHC6H4
e
50
50
e
e
39.27**
37.16**
38.39**
69.13**
71.09*** >800
65.82*** >800
63.56*** >800
93.34*** >800
4- N(CH3)2C6H4 50
e
4-CH3C6H4
2-Cl C6H4
50
25
e
133.33
8g
50
100
50
8h
2-OCH3C6H4
Phenylbutazone
e
66.66
38.68*** 64.28*** >800
e
25
50
e
>800
100
Indomethacin
5.0
7.5
52.20***
63.10***
93.20***
5.0
7.5
54.60
e
e
e
10.0
10.0
*P < 0.05; **P < 0.01; ***P < 0.001.
Propylene glycol standard for control group.
5.2.1. Anti-inflammatory activity against carrageenan-
induced rat’s paw oedema
5.2.2. Analgesic activity
Analgesic activity was performed following the method of
Berkowitz et al. [19]. This method is based on the property of
the test compound to antagonize the phenylquinone-induced
pain syndrome in mice. Groups of five mice were injected in-
traperitonealy with 0.25 ml of a 0.02% solution of phenylqui-
none in ethanol (5%) 1 h after oral administration of the test
compound. The number of writhes induced in each mouse
was counted for 5 min (between 5 and 10 min) after injection
of an irritant. The analgesic effect was expressed as percent
protection in comparison to control.
This study was done following the procedure of Winter
et al. [18]. The rats were divided into three groups (control,
drug treated, and standard, drug of six animals each). A freshly
prepared suspension of carrageenan (1% in 0.9% saline).
0.05 ml was injected under the planter aponeurosis of the right
hind paw of each rat. Test compounds and standard drug were
administered orally to the animals of drug treated groups and
the standard drug group, respectively, 1 h before the carra-
geenan injection. The paw volume of each rat was measured
before 1 and after 3 h of carrageenan treatment with the
help of a plethymometer. The percent anti-inflammatory activ-
ity was calculated according to the formula given below:
%protection¼ð1ꢂmeanno:of writhesinmiceof testgroups=
meannumberof writhesinmiceof controlgroupÞꢃ100
Percentage of inhibition of oedema ¼ ð1 ꢂ Vt=VcÞ ꢃ 100
5.2.3. Ulcerogenic activity
where, Vt and Vc are the mean increase in paw volume of rats
of the treated and the control group, respectively. Results ob-
tained were statistically analyzed.
Ulcerogenic labilities of newly synthesized compounds
were checked with method of Verma et al. [20]. Albino rats
were fasted for 24 h prior to drug administration. All animals

S.K. Bhati, A. Kumar / European Journal of Medicinal Chemistry 43 (2008) 2323e2330
2329
Table 5
Spectral data of compounds (6ae8h)
Compound
[M]þ at m/z
1H NMR (CDCl3 þ DMSOd6)
6.82e7.30 (m, 9H, Ar-H), 4.65 (d, 2H, NHeCH2), 5.90
IR (KBr) in cmꢂ1
6a
403
3042 (CeH), 1572 (C]N), 3270 (NeH), 1290 (NeN),
728 (CeSeC)
(t, 1H, NH2), 7.98 (s, 1H, CH-Ar)
6b
6c
[M]þ437 [M þ 1]þ 438
[M þ 2]þ 439
433
6.85e7.28 (m, 8H, Ar-H), 4.68 (d, 2H, NHeCH2), 5.94
(t, 1H, NH2), 7.95 (s, 1H, CH-Ar)
3045 (CeH), 1570 (C]N), 3275 (NeH), 1295 (NeN),
730 (CeSeC)
6.80e7.25 (m, 8H, Ar-H), 4.70 (d, 2H, NHeCH2), 5.88
(t, 1H, NH2), 7.97 (s, 1H, CH-Ar), 3.28 (s, 3H,
Ar-OCH3)
3050 (CeH), 1575 (C]N), 3278 (NeH), 1285 (NeN),
735 (CeSeC), 1165(CeOeC), 1695 (C]O)
6d
6e
419
446
6.82e7.20 (m, 8H, Ar-H), 4.78 (d, 2H, NHeCH2), 5.80
(t, 1H, NH), 8.02 (s, 1H, CH-Ar), 9.98 (s, 1H, Ar-OH)
7.05e7.35 (m, 8H, Ar-H), 4.72 (d, 2H, NHeCH2), 5.85
(t, 1H, NH), 8.10 (s, 1H, CH-Ar), 2.94 (s, 6H,
Ar-N(CH3)2)
3040 (CeH), 1580 (C]N), 3280 (NeH), 1295 (NeN),
725 (CeSeC), 1690 (C]O)
3035 (CeH), 1585 (C]N), 3285 (NeH), 1280 (NeN),
705 (CeSeC)
6f
417
6.95e7.25 (m, 8H, Ar-H), 4.67 (d, 2H, NHeCH2), 5.90
(t, 1H, NH), 8.05 (d, 1H, CH-Ar), 3.68 (s, 3H, Ar-CH3)
7.00e7.28 (m, 8H, Ar-H), 4.75 (d, 2H, NHeCH2), 5.98
(t, 1H, NH), 7.90 (s, 1H, CH-Ar)
3030 (CeH), 1582 (C]N), 3283 (NeH), 1282 (NeN),
698 (CeSeC)
3032 (CeH), 3278 (NeH), 1572 (C]N), 1290 (NeN),
725 (CeSeC), 668 (CeCl)
6g
6h
[M]þ437 [M þ 1]þ 438
[M þ 2]þ 439
433
6.90e7.32 (m, 8H, Ar-H), 4.80 (d, 2H, NHeCH2), 5.92
(t, 1H, NH), 7.87 (s, 1H, CH-Ar), 3.35 (s, 3H,
Ar-OCH3)
3037 (CeH), 1578 (C]N), 3287 (NeH), 1280 (NeN),
720 (CeSeC), 1168 (CeOeC), 1685 (C]O)
7a
7b
7c
7d
7e
7f
477
7.05e7.70 (m, 9H, Ar-H), 4.50 (d, 2H, NHeCH2), 6.08
(t, 1H, NH), 4.40 (s, 1H, CHeN), 2.85 (s, 2H, CH2)
3030 (CeH), 1590 (C]N), 3295 (NeH), 1270 (NeN),
710 (CeSeC), 1480 (CeN of eNeCH-Ar), 1695
(C]O)
3025 (CeH), 1595 (C]N), 3320 (NeH), 1275 (NeN),
715 (CeSeC), 1485 (CeN of eNeCH-Ar), 670
(CeCl), 1690 (C]O)
3035 (CeH), 1585 (C]N), 3325 (NeH), 1280 (NeN),
705 (CeSeC), 1482 (CeN of eNeCH-Ar), 1170
(CeOeC), 1700 (C]O)
[M]þ511 [M þ 1]þ 512
[M þ 2]þ 513
7.10e7.75 (m, 8H, Ar-H), 4.60 (d, 2H, NHeCH2), 6.10
(t, 1H, NH), 4.36 (s, 1H, CHeN), 2.90 (s, 2H, CH2)
507
493
520
491
7.15e7.80 (m, 8H, Ar-H), 4.57 (d, 2H, NHeCH2), 6.12
(t, 1H, NH), 4.30 (s, 1H, CHeN), 3.40 (s, 3H,
Ar-OCH3), 2.86 (s, 2H, CH2)
7.12e7.77 (m, 8H, Ar-H), 4.62 (d, 2H, NHeCH2), 6.09
(t, 1H, NH), 4.38 (s, 1H, CHeN), 9.95 (s, 1H, Ar-OH),
2.82 (s, 2H, CH2)
3038 (CeH), 1600 (C]N), 3330 (NeH), 1265 (NeN),
700 (CeSeC), 1475 (CeN of eNeCH-Ar), 3415
(OH), 1680 (C]O)
7.10e7.72 (m, 8H, Ar-H), 4.65 (d, 2H, NHeCH2), 6.15
(t, 1H, NH), 4.42 (s, 1H, CHeN), 2.80 (s, 2H, CH2),
2.98 (s, 6H, Ar-N(CH3)2)
3022 (CeH), 1588 (C]N), 3322 (NeH), 1270 (NeN),
720 (CeSeC), 1460 (CeN of eNeCH-Ar), 1688
(C]O)
7.06e7.70 (m, 8H, Ar-H), 4.70 (d, 2H, NHeCH2), 6.12
(t, 1H, NH), 4.36 (s, 1H, CHeN), 2.85 (s, 2H, CH2),
3.70 (s, 3H, Ar-CH3)
3020 (CeH), 1592 (C]N), 3328 (NeH), 1278 (NeN),
725 (CeSeC), 1465 (CeN of eNeCH-Ar), 1692
(C]O)
7g
7h
8a
8b
8c
8d
8e
8f
[M]þ511 [M þ 1]þ 512
[M þ 2]þ 513
6.95e7.62 (m, 8H, Ar-H), 4.54 (d, 2H, NHeCH2), 6.11
(t, 1H, NH), 4.32 (s, 1H, CHeN), 2.87 (s, 2H, CH2)
3025 (CeH), 1598 (C]N), 3335 (NeH), 1280 (NeN),
730 (CeSeC), 1472 (CeN of eNeCH-Ar), 1698
(C]O), 675 (CeCl)
3015 (CeH), 1594 (C]N), 3320 (NeH), 1285 (NeN),
728 (CeSeC), 1477 (CeN of eNeCH-Ar), 1695
(C]O)
507
6.98e7.75 (m, 8H, Ar-H), 4.55 (d, 2H, NHeCH2), 6.05
(t, 1H, NH), 3.44 (s, 3H, Ar-OCH3), 4.34 (s, 1H,
CHeN), 2.87 (s, 2H, CH2)
[M]þ479 [M þ 1]þ 480
[M þ 2]þ 481
7.08e7.68 (m, 9H, Ar-H), 4.50 (d, 2H, NHeCH2), 6.02
(t, 1H, NH), 4.35 (d, 1H, eNeCH), 4.82 (d, 1H,
CHeCl)
3020 (CeH), 1585 (C]N), 3310 (NeH), 1280 (NeN),
715 (CeSeC), 1485 (CeN of eNeCH-Ar), 1690
(C]O), 675 (CeCl)
[M]þ514 [M þ 1]þ 515
7.12e7.73 (m, 8H, Ar-H), 4.52 (d, 2H, NHeCH2), 6.05
(t, 1H, NH), 4.38 (d, 1H, eNeCH), 4.85 (d, 1H,
CHeCl)
3015 (CeH), 1590 (C]N), 3315 (NeH), 1275 (NeN),
720 (CeSeC), 1480 (CeN of eNeCH-Ar), 670
(CeCl), 1685 (C]O)
[M þ 2]þ 516
[M]þ509 [M þ 1]þ 510
[M þ 2]þ 511
7.15e7.70 (m, 8H, Ar-H), 4.55 (d, 2H, NHeCH2), 6.10
(t, 1H, NH), 4.42 (d, 1H, eNeCH), 4.80 (d, 1H,
CHeCl), 3.42 (s, 3H, Ar-OCH3)
3025 (CeH), 1580 (C]N), 3320 (NeH), 1290 (NeN),
710 (CeSeC), 1170 (CeOeC), 1695 (C]O), 677
(CeCl), 1475 (CeN of eNeCH-Ar).
[M]þ495 [M þ 1]þ 496
7.10e7.65 (m, 8H, Ar-H), 4.60 (d, 2H, NHeCH2), 6.15
(t, 1H, NH), 4.45 (d, 1H, eNeCH), 4.88 (d, 1H,
CHeCl), 10.12 (s, 1H, Ar-OH)
7.05e7.72 (m, 8H, Ar-H), 4.57 (d, 2H, NHeCH2), 6.12
(t, 1H, NH), 4.39 (d, 1H, eNeCH), 4.84 (d, 1H,
CHeCl), 2.92 (s, 6H, Ar-N(CH3)2
3010 (CeH), 1600 (C]N), 3325 (NeH), 1265 (NeN),
710 (CeSeC), 1495 (CeN of eNeCH-Ar), 3410
(OH), 1680 (C]O), 665 (CeCl)
3015 (CeH), 1595 (C]N), 3320 (NeH), 1270 (NeN),
715 (CeSeC), 1490 (CeN of eNeCH-Ar), 3410
(OH), 1690 (C]O), 670(CeCl)
[M þ 2]þ 497
[M]þ522 [M þ 1]þ 523
[M þ 2]þ 524
[M]þ493 [M þ 1]þ 494
6.97e7.62 (m, 8H, Ar-H), 4.54 (d, 2H, NHeCH2), 6.18
(t, 1H, NH), 4.33 (d, 1H, eNeCH), 4.89 (d, 1H,
CHeCl), 3.65 (s, 3H, Ar-CH3)
3020 (CeH), 1590 (C]N), 3315 (NeH), 1275 (NeN),
720 (CeSeC), 1485 (CeN of eNeCH-Ar), 1685
(C]O), 675 (CeCl)
[M þ 2]þ 495

2330
S.K. Bhati, A. Kumar / European Journal of Medicinal Chemistry 43 (2008) 2323e2330
Table 5 (continued)
Compound
[M]þ at m/z
1H NMR (CDCl3 þ DMSOd6)
7.09e7.67 (m, 8H, Ar-H), 4.48 (d, 2H, NHeCH2), 6.05
(t, 1H, NH), 4.30 (d, 1H, eNeCH), 4.91 (d, 1H,
CHeCl)
IR (KBr) in cmꢂ1
8g
[M]þ514 [M þ 1]þ 515
3025 (CeH), 1595 (C]N), 3310 (NeH), 1280 (NeN),
715 (CeSeC), 1480 (CeN of eNeCH-Ar), 670
(CeCl), 1695 (C]O)
[M þ 2]þ 516
8h
[M]þ509 [M þ 1]þ 510
[M þ 2]þ 511
7.13e7.74 (m, 8H, Ar-H), 4.59 (d, 2H, NHeCH2), 6.13
(t, 1H, NH), 4.48 (d, 1H, eNeCH), 4.86 (d, 1H,
CHeCl), 3.47 (s, 3H, Ar-OCH3)
3010 (CeH), 1585 (C]N), 3320 (NeH), 1285 (NeN),
710 (CeSeC), 1170 (CeOeC), 1690 (C]O), 1475
(CeN of eNeCH-Ar), 675 (CeCl)
were sacrificed 8 h after drug treatment, and their stomachs
and small intestines were microscopically examined to assess
the incidence of hyperemia, shedding of epithelium, petechial
and frank hemorrhages and erosion or discrete ulceration with
or without perforation. The presence of any one of these crite-
ria was considered to be an evidence of ulcerogenic activity.
Acknowledgements
We are thankful to CDRI, Lucknow, for elemental and
spectral analyses of newly synthesized compounds.
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