Synthesis, antioxidant, and antimicrobial activity of 3‐(1H‐indole‐3‐carbonyl)‐2H‐chromen‐2‐ones

Abstract

AbstractA simple and convenient method for the one‐pot synthesis of 3‐(1H‐indole‐3‐carbonyl)‐2H‐chromen‐2‐one derivatives from the reaction of 3‐cyanoacetyl indole and salicylaldehyde in the presence of Na2CO3 in water: methanol (1:1) is described. Wider substrate scope, high yields, operational simplicity, and simple purification process make the protocol highly applicable in the synthesis of 3‐(1H‐indole‐3‐carbonyl)‐2H‐chromen‐2‐ones. For the first time, in vitro antioxidant and antimicrobial activity was studied. Compounds 5e, 7a, and 7b exhibits good radical scavenging ability against DPPH free radical. Compounds 7b, 5f, and 5g possess lower EC50 values than the Standards AA and BHA and thus proving their high reducing power. Compounds 5d and 5f show good antibacterial activity against gram‐positive bacteria (MRSA) while compounds 5c, 7a, and 7b exhibits good antibacterial activity against Bacillus sp. Compounds 5b and 5e show good antibacterial activity against gram negative bacterial strains (Escherichia coli, Klebsiella pneumoniae) and compounds 5g and 5h exhibits good antifungal activity against Candida albicans.