Synthesis, characterization and antihypertensive activity of 2-phenyl substituted benzimidazoles

Hypertension is one of cardiovascular disease that is not sufficiently prevented and controlled at both hospital and community levels. Hypertension resulted in significant morbidity and mortality. The benz-imidazole ring is very important pharmacophore in modem drug discovery. The substituted benzimidazoles are the important for medicinal research. Researchers have reported that substituted Benzimidazoles are the structural isosteres of nucleotides, and easily allow them to interact with the different biopolymers, possess pharmacological activity especially antihypertensive activity. Angiotensin II Receptor Antagonists/Blockers (ARBs) compete with angiotensin II at the receptor site and block the contractile effect of angiotensin II in all vascular smooth muscles. Among all Angiotensin II Receptor Antagonists/Blockers (ARBs), Telmisartan, Milfasartan and many others have benzimidazole ring in their structure. In this study Angiotensin II Receptor Antagonists/Blockers (ARBs) have been prepared. Synthesized compounds were characterized by physical data and FTIR spectroscopic technique. Synthesized compounds studied were finally screened for their antihypertensive activity by tail cuff method of measurement of blood pressure by NIBP apparatus (None Invasive Blood Pressure) using Chart 5.0 software. The compounds synthesized were 2-(3-nitrophenyl)-1H-benzimidazole (1a), 3-(1H benzimidazol-2-yl)aniline (lb) and 5-(1H-benzimidazol-2-y1)-2-methoxyphenol (1c). The synthesized compounds have shown antihypertensive activity by taking Losartan as lead compound.