Dangi et al Journal of Drug Delivery & Therapeutics; 2014, 4(2), 182-185 182
© 2011, JDDT. All Rights Reserved ISSN: 2250-1177 CODEN (USA): JDDTA
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RESEARCH ARTICLE
SYNTHESIS, ANTICONVULSANT ACTIVITY OF SOME NOVEL BENZIMIDAZOLE
ACETOHYDRAZIDES
Girija Dangi
1*
Neeraj Kumar
1
, Chandra Shekhar Sharma
2
, Lalit Singh Chauhan
3
1
Department of Pharmaceutical Chemistry, Geetanjali Institute of Pharmacy, Udaipur, India
2
Department of Pharmaceutical Chemistry, BN College of Pharmacy, Udaipur, India
3
Department of Pharmaceutical Sciences, Mohanlal Sukhadia University, Udaipur
INTRODUCTION:
Benzimidazole is very useful heterocyclic
compound/intermediate for the development of
molecules of pharmaceutical or biological interest.
1
Derivatives of benzimidazole possess a wide range of
pharmacological activities such as Anti-neoplastic,
analgesic, Anthelmintics, Anti-ulcer, anti-inflammatory,
Antifungal, Anti-histaminic, Antiviral and Anti-
diabetic.
2-7
Numerous publication have shown that benzimidazole
derivatives also have anticonvulsant activity.
8-12
An attempt has been made in our study to synthesize
Benzimidazole acetohydrazide derivatives to get as
potent anticounvulsant compounds. The newly
synthesized Benzimidazole acetohydrazide derivatives
were evaluated for anticonvulsant activity by the MES
method using phenytoin as standard.
MATERIAL AND METHODS:
1H-benzimidazole (1a). A mixture of o-
phenylenediamine (27 g, 0.25 mol) and formic acid (16
ml, 85 %) was refluxed on a water bath for 2 h. The
reaction mixture was cooled and its pH was adjusted to 8
by addition of sodium hydroxide (10 %) solution. The
crude product so obtained was filtered, thoroughly
washed with ice cold water and dried. The dried product
was boiled with decolourising charcoal (2 g) in water
(400 ml) for 15 min and filtered while hot. The solution
thus obtained was allowed to cool at 10
°
C for 30 min,
filtered and dried. The completion of reaction was
monitored by running TLC.
Yield: 88 %, R
f
value: 0.46, M.p. 170-172 ºC. IR (KBr in
cm
-1
): 3115 (N-H), 3048 (Ar. C-H), 1362 (C=N). Anal.
calcd. for C
7
H
6
N
2
(118.14): C, 71.17; H, 5.12; N, 23.71.
Found: C, 71.22; H, 5.16; N, 23.31 %. LCMS m/z: 118.1
(M+).
NH
2
NH
2
RCOOH
NH
N
R
-HCl
N
N
R
NH NH
.
H O
N
N
R
CH
2
COOC
2
H
5
(1a-1f)
(2a-2f)
(3a-3f)
CH
2
CONHNH
2
Comp. R
3a -H
3b -CH
3
3c -CH
2
C
6
H
5
3d -C
6
H
5
3e 4-ClC
6
H
4
3f 4-(CH
3
)NC
6
H
4
ClCH
2
COOC
2
H
5
Scheme 1 Reaction Protocol for the synthesis of 3a-3f
*Corresponding Author:
Girija Dangi
Department of Pharmaceutical Chemistry,
Geetanjali Institute of Pharmacy, Udaipur, India
Email: girijadangi@gmail.com
ABSTRACT:
A series of some novel benzimidazole acetohydrazide derivatives was synthesized and characterized by TLC, MP, elemental
analysis, IR, Mass and
1
H NMR spectroscopy. These compounds were screened for anticonvulsant activities by Maximum
Electroshock seizure model in male wistar rats and compared with the standard drug phenytoin.
Keywords: Benzimidazole, hydrazide, Anticonvulsant, MES