Synthesis, Characterization and Antimicrobial Activity of Some Novel Mannich Bases of Indole-2,3-dione

Abstract

Indole-2,3-dione (isatin) and its 5-substituted derivatives have been reacted with N2-benzylidenepyridine-2,6-diamine to form Schiff bases and the Mannich bases of these compounds were synthesized by reacting them with some secondary amines in presence of formaldehyde. Their chemical structures have been confirmed by mean of their IR and 1H NMR. Antimicrobial screening of synthesized compounds was done by well diffusion method against 4 pathogenic bacteria and 2 pathogenic fungi. Amongst the tested compounds 3-{[6-(benzylideneamino)pyridin-2-yl]imino}-1- (piperazin-1-ylmethyl)-5-fluoro-indolin-2-one and 3-{[6-(benzylideneamino)pyridin-2-yl]-imino}-1- (morpholin-4-ylmethyl)-5-fluoro-indolin-2-one showed significant antibacterial activity and 3-{[6- (benzylideneamino)pyridin-2-yl]imino}-1-(piperazin-1-ylmethyl)-5-methyl-indolin-2-one and 3-{[6- (benzylideneamino)pyridin-2-yl]imino}-1-(morpholin-4-ylmethyl)-5-methyl-indolin-2-one showed the favourable antifungal activity.