Synthesis, Chemical Characterization and Antimicrobial Activity of Some Novel Benzimidazole Derivatives.

Abstract

The starting compound 2-mercapto benzimidazole (1a) / 5-methyl-2-mercapto benzimidazole (1b) was prepared from o-phenylene diamine / 4-methyl benzene-1,2-diamine, potassium hydroxide and carbon disulfide upon refluxing for 3 h in single step respectively. The 2-mercapto benzimidazole (1a) / 5-methyl-2-mercapto benzimidazole (1b) was refluxed for 60 min with potassium hydroxide, followed by chloro acetic acid and stirred for 18 h to furnish 1H-benzimidazol-2-ylthio acetic acid (2a) / 5-methyl-1H-benzimidazol-2-ylthio acetic acid (2b) respectively. The different Mannich bases (3a₁-3a₁₂) were synthesized by refluxing the appropriate substituted amines, formaldehyde with 1H-benzimidazol-2-ylthio acetic acid (2a) and 5-methyl-1H-benzimidazol-2-ylthio acetic acid (2b) in ethanolic medium for 12 h. The synthesized compounds were characterized by their physical and spectral data.

KEYWORDS: Benzimidazole, Carbon disulphide, Triazole, Tetrazole, Anti microbial activity.