Synthesis and antimicrobial activity of 5-substituted-2-phenyl-3-(o-carboethoxyphenyl)iminomethyl indoles and their derivatives

Abstract

5-Substituted indole-3-carboxaldehydes (1a-c) on reaction with ethyl anthranilate (2) in ethanol under reflux for 8 h in presence of catalytic amount of concentrated hydrochloric acid gave 5-substituted-2-phenyl-3-(o-carboxyphenyl)iminomethyl indoles (3a-c), which on further reaction with hydrazine hydrate in ethanol under reflux for 5 h yielded 5-substituted-2-phenyl-3-(o-carboethoxyhydrazidophenyl)iminomethyl indoles (4a-c). Compounds (4a-c) on reaction with acetyl acetone/ethyl acetoacetate and ethylcyanoacetate in ethanol under reflux conditions for 5 h in presence of catalytic amount of glacial acetic acid furnished 5-substituted-2-phenyl-3[o-carboxy-(3',5'-dimethylpyrazol/3'-methylpyrazol-5'-one/3'-aminopyrazol-5'-one-1'-)ylphenyl]iminomethyl indoles (5a-c), (6a-c) and (7a-c), respectively. All the newly synthesized compounds have been tested for their antimicrobial activity against E. coli, S. aureus, P. vulgaris, A. lager and C. albicans. Some of the compounds exhibited good activity against all the microorganisms tested.