Synthesis and Biological Investigations of Some New Thiazolylbenzimidazoles and Benzimidazolylthiazolo[3,2-a]pyridines

2-[(4-Oxo-4,5-dihydrothiazol-2-yl)methyl]-1H-benzimidazole ( 2 ) was prepared through the reaction of 2-cyanomethyl-1H-benzimidazole ( 1 ) with thioglycolic acid. The syntheses of its arylidene 3 and diazo-coupled compounds 5 and the cyclization of the aforementioned thiazolylbenzimidazole to benzimidazolylthiazolo[3,2-a]pyridines 8 were also performed. The prepared compounds were screened for their in-vitro antibacterial, antifungal, anti-HIV, and anticancer activities: they show promising antifungal activity.