Synthesis of novel benzimidazole derivatives: as potent analgesic agent

1-(1-Alkyl-6-substituted-1H-benzimidazol-2-yl)-naphthalen-2-ols have been synthesized using o-phenylinediamine and naphthaldehyde in the presence of sodium hydride and THF. 1-(1-Alkyl-6-substituted-1H-benzimidazol-2-yl)-naphthalen-2-ols were evaluated for the analgesic activity by tail flick method in rats. Synthesized1-(1-alkyl-6-substituted-1H-benzimidazol-2-yl)-naphthalen-2-ols in doses of 50 mg/kg increased the pain threshold significantly after 0, 30, 60, 90, and 120 min of administration in the tail flick model. Compounds B(3)a, B(2)b, and B(1)b showed time-dependent action in all the experimental models. The present study indicates that Compounds B(3)a, B(2)b, and B(1)b show analgesic properties.