Synthesis and antimicrobial activity of some indole derivatives containing pyrazoline and benzodiazepine systems

Abstract

3,5-Substituted indole-2-carboxyhydrazides 1a-d on diazotisation followed by coupling with ethyl acetoacetate gave 2-(3?,5?-substituted- 2?-indolinoylaminoazo) ethyl acetoacetates 2a-d, which on condensation with benzaldehyde in basic medium gave 1-(3?,5?-substituted- 2?-indolinoylaminoazo) propan-2-ones 3a-d. The compounds 3a-d on treatment with hydrazine hydrate and hydrazine hydrate-gl acetic acid yielded 5-phenyl-1H/acetyl-3-(3?,5?-substituted-2?- indolinoylaminoazomethyl)-2-pyrazolines 4a-d and 5a-d respectively. The chalcones 3a-d on reaction with phenyl hydrazine containing catalytic amount of piperidine gave 1,5-diphenyl-3-(3?,5?-substituted-2?- indolinoylaminazomethyl)-2-pyrazolines 6a-c. The compounds 3a-d on reaction with o-phenylenediamine gave 4-phenyl-2-(3?,5?-substituted-2?- indolinoylaminoazomethyl)-benzodiazepines 7a-d. Structures of all these unknown compounds were confirmed by their spectral studies and elemental analysis. These compounds were screened for their antibacterial activity against S. aureus and E.coli and antifungal activity against A. flavus and A. niger.