Synthesis and Pharmacological Evaluation of Some Novel Imidazole Derivatives for Their Potential Anti-Hypertensive Activity

Benzimidazole, which is a heterocyclic nucleus, plays an important role in various medicines. A number of therapeutic agents such as H1 antihistaminic agent clemizole, a potent opioid analgesic etonitazene, nonnucleoside antiviral compound enviroxime, for promotion of excretion of uric acid irtemazole, non sedating antihistaminic agent astemizole, anti ulcer drugs omeprazole and pentoprazole, antihelmintic thiabendazole, antinematodal nocodazole etc. are based on benzimidazole heterocyclic nucleus. The synthesis of various benzimidazole derivatives by the reaction of ortho phenylene diamine I with various organic acids to yield 2-substituted benzimidazole derivatives II which on further treatment with nitric acid and sulphuric acid yielded 5-nitro-2substituted benzimdazoles III. Coupling of this compound with halogenated beta picoline V yielded the title compounds. The structures of synthesized compounds were elucidated mainly by spectral evidence. All the compounds were screened for their anti-hypertensive activity. The compounds exhibited moderate to significant activities.