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

Abstract

A facile synthesis of eighteen's novel derivatives of spiro[indole-thiazolidine]diones (<strong>5a-5r</strong>) has been developed <em>via</em> 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 <em>tert</em>-butyl ammonium bromide to get 1a-1i. In the second step, <em>N</em>-substituted isatin (<strong>1a-1i</strong>) reacted with different amine compounds (<strong>2a-2f</strong>) to get schiff base intermediates (<strong>3a-3r</strong>). 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 (<strong>2a-2d</strong>), phenylpyrazole (<strong>2e</strong>) and oxazole (<strong>2f</strong>) 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.