Chemoselective reaction of indole 1,3-dicarboxylates towards hydrazine hydrate: Bisheterocycles: Synthesis and antimicrobial activity of some new 2-methyl-3-ethoxycarbonyl-1-oxadiazolyl/thiazolidinonyl/pyrrolyl­aminocarbonylmethylindoles

Abstract

Chemoselectivity of 1-ester over C₃-ester of the indole dicarboxylates <b style="">3a,b</b> towards the nucleophilic attack of hydrazine hydrate has been evidenced by the exclusive formation of 1-hydrazinocarbonylmethyl-3-ethoxycarbonyl-5-substituted-2-methylindoles <b style="">5a,b</b> which have been further reacted separately with CS₂/KOH, <i>p</i>-chlorobenzaldehyde and acetonyl acetone to furnish the 1-(5-mercapto-1,3,4-oxadiazol-2-yl)methyl-3-ethoxycarbonyl-5-substituted-2-methylindoles <b style="">6a,b</b>, 1-<i>p</i>-Chlorobenzyl­idene­hydrazinocarbonylmethyl-3-ethoxycarbonyl-5-substituted-2-methylindoles <b style="">7a,b</b> and 1-(2,5-dimethyl­pyrrol-1-yl)­amino­carbonylmethyl-3-ethoxycarbonyl-5-substituted-2-methylindoles <b style="">8a,b</b> respectively. The Schiff’s bases <b style="">7a,b</b> are reacted separately with thioglycolic acid to get the desired 1-(2-<i>p</i>-chlorophenyl-4-thiazolidinon-1-yl)aminocarbonylmethyl-3-ethoxycarbonyl-5-substituted-2-methylindoles <b style="">9a,b</b>. These newly synthesised compounds are screened for their antibacterial and antifungal activities.