An Efficient Method for Synthesis of Some Novel Spiro[indoline-thiazolidine]dione Derivatives

A facile synthesis of eighteen’s novel derivatives of spiro[indole-thiazolidine]diones (5a-5r) has been developed via hitherto unknown schiff bases. In the first step, we alkylated the isatin ring using different alkyl halides in DMF and in the presence of potassium carbonate and tert-butyl ammonium bromide to get 1a-1i. In the second step, N-substituted isatin (1a-1i) reacted with different amine compounds (2a-2f) to get schiff base intermediates (3a-3r). In the third step, cyclocondensation reaction with mercaptoacetic acid afforded a new class of spiro diones. The amine moieties which are used in the second step of this synthesis are varied from aniline derivatives (2a-2d), phenylpyrazole (2e) and oxazole (2f) analogues. Of the 18 final new compounds 9 analogues derived from aniline, 2 analogues derived from oxazole and 7 of them synthesized from phenylpyrazole analogues. Chemical structures of all new compounds were confirmed by spectroscopic methods such as IR, HNMR and CNMR.