Studies on analgesic and anti-inflammatory activities of 1-dialkylaminomethyl-2-(p-substituted phenyl)-5-substituted benzimidazole derivatives.

In this study the analgesic and anti-inflammatory activity of 1,2,5-trisubstituted benzimidazole derivatives have been examined. Analgesic activities of these compounds were investigated by using the modified Koster test. Among the compounds synthesized especially compound 1g (1-diethylaminomethyl)-2-(p-chlorophenyl)-5-nitro benzimidazole hydrochloride) has shown higher activity than acetylsalicylic acid (ASA) and indometacin. Compound 1e (1-(diethylaminomethyl)-2-(p-methoxyphenyl)-5-nitro benzimidazole hydrochloride, 1f (1-(diethylaminomethyl)-2-(p-tolyl)-5-nitro benzimidazole hydrochloride and 1i (1-(pipenridinomethyl)-2-(p-methoxyphenyl)-5-nitro benzimidazole hydrochloride) proved as potent as the standard ASA. Therefore the compounds 1e, 1f, 1g and 1i were screened for their anti-inflammatory activities using the carrageenan-induced hind paw edema test. Except 1g all compounds were almost inactive against this model of inflammation compared to indometacin.