Nucleophilic addition of hydrazines and thiosemicarbazide to the 2-(2-oxoindolin-3-ylidene) malononitrile derivatives 1, followed by elimination of malononitrile, lead to 3-(2- arylhydrazono) indolin-2-ones and 1-(2-oxoindolin-3-ylidene) thiosemicarbzides respectively. Also the reaction of compounds 1 with 4-substituted thiosemicarbazides, followed by elimination and cyclization, afforded spiro (indolone-3, 2＇-[1, 3, 4] thiadiazol)-2 ...
