Synthesis and antileukemic activity of spiro[indoline‐3,2′‐thiazolidine]‐2,4′‐diones

A number of spiro[indoline‐3,2′‐thiazolidine]‐2,4′‐diones have been prepared via the cyclocondensation of isatin‐3‐imines with α‐mercaptoacids. 1‐Benzyl‐5′,5′‐dimethylspiro[indoline‐3,2′‐thiazolidine]‐2,4′‐diones were prepared by simultaneously refluxing 1‐benzylisatin, α‐mercaptoisobutyric acid and various anilines in toluene. 3′‐(4‐Chlorophenyl)‐5,5′‐dimethylspiro[indoline‐3,2′‐thiazolidine]‐2,4′‐dione was active in the P388 and the L1210 leukemia screen tests. A number of analogs of the active spiro compound have been prepared and submitted for antileukemic screening. Anticonvulsant screening results of related compounds are also included.