Design, synthesis and screening of some novel benzoxazole based 1,3,4-oxadiazoles as potential antimicrobial agents

A series of novel 2-(5-substituted-[1,3,4]oxadiazol-2-yl)-benzoxazoles (7a-h) were synthesized in good yields in two different directions by involving benzoxazole-2-carboxylic acid (1) as raw material and benzoxazole-2-carbonyl chloride (2), benzoxazole-2-carboxylic acid methyl ester (3), benzoxazole-2-carboxylic acid hydrazide (4), benzoxazole-2-carboxylic acid N'-acetyl hydrazide (5a-d) and benzoxazole-2-carboxylic acid-ethylidene-hydrazides (6a-d) as reactive intermediates. The chemical structures of all the synthesized compounds were elucidated by their IR, H-1 NMR and C-13 NMR and mass spectral data. Further, the target compounds were screened for their antimicrobial activity against various Gram-positive and Gram-negative bacteria. (C) 2013 Raghu Vardhan Reddy Mekala. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.