A series of 5-substituted indole- 2,3-dione based spiro-4-thiazolidiones were synthesized, characterization and evaluated for their antimicrobial activity. Condensation of 5-substituted indole-2,3-dione with substituted primary aryl amine was formed series of Schiff bases (1) which on reaction with thioglycolic acid and thiolactic acid in 1,4-dioxane afforded the formation of the corresponding 4-thiazolidinones (2, 3). All the synthesized compounds were characterized on the basis of their IR, 1H and 13C NMR and elemental analysis. The antimicrobial activity of all the compounds (D01-D04, E01-E04) showed significant activity against the selected micro organisms
5-Substituted indole -2,3-dione, Spiro-4-thiazolidiones, Antimicrobial