Synthesis Of Some New Benzimidazole Acetic Acid Derivatives And Evaluation For Their Antimicrobial And Antitubercular Activities

Abstract

A new series of benzimidazoles acetic acid derivatives were synthesized by reacting 2(2-substituted phenyl ethenyl) 1H benzimidazole with chloroacetic acid under reflux. Despite the availability of highly potential antitubercular agents, tuberculosis remains primary cause of comparatively high mortality worldwide. The statistics shows that around three million people through out the world die annually from tuberculosis and today more people die from tuberculosis than ever before. Therefore, the development of new drugs with activity against multi drug- resistant (MDR) TB, extensively drug –resistant (XDR) TB, and latent TB is a priority task. Although new agents that will shorten the duration of current chemotherapy are also needed. A literature survey indicates that benzimidazole derivatives possess different biological activities such as antimicrobial activity, anti-ulcer, antiparasitic, antiprotozoal antiviral and antitubercular and physical properties shown that, benzimidazoles have high melting points, benzimidazoles are usually soluble in polar solvents and sparingly soluble in non polar solvent,benzimidazoles are weakly basic, being some what less basic than imidazole, benzimidazoles are also sufficiently acidic to be generally soluble in aqueous alkali. The acidic properties of benzimidazoles, like those of imidazole, seem to be due to stabilization of the ion by resonance. The pKa value of benzimidazoles (pKa=5.30). The structures of these compounds were established by means of IR, 1H-NMR and elemental analysis. All compounds were evaluated for antibacterial, antifungal and antitubercular activities. Most of the compounds have shown significant antibacterial, antifungal and antitubercular activity when compared with the standard drug.