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

Department of Chemistry, Gulbarga University, Gulbarga-585 106, Karnataka, India

E-mail: bhmmswamy53@rediffmail.com

GVK Biosciences Private Limited, Medicinal Chemistry Laboratory, Plot No. 28, IDA, Nacharam,

Hyderabad-500 076, India

Manuscript received 10 June 2009, revised 10 February 2010, accepted 16 March 2010

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-substltuted-2-phenyl-3-(o-carboxy-phenyl)iminomethyl indoles (3a-c), which on further reaction with hydrazine hydrate in ethanol under reflux for 5 h yielded 5-substltuted-2-phenyl-3-(o-carboethoxyhydrazidophenyl)iminomethyl indoles (4a-c). Compounds (4a-c) on reaction with acetyl acetone/ethyl acetoacetate and ethyicyanoacetate in ethanol under reflux conditions for 5 h In presence of catalytic amount of glacial acetic acid furnished 5-substituted-2-pheuyl-3-[o-carboxy-(3' ,5' -dimethylpyrazol/3' -methyl-pyrazol-5'-one/3'-amlnopyrazol-5'-one-1'-)ylphenyllimlnomethyl 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. niger and C. albicans. Some or the compounds exhibited good activity against all the microorganisms tested.