Synthesis of 2,4′-dioxospiro[indoline-3,2′-thiazolidine]-5′-acetic acids: X-ray structure of 1-benzyl-3′-(4-chlorophenyl)-2,4′-dioxospiro- [indoline-3,2′-thiazolidine]-5′-acetic acid

The title compounds have been prepared by the cyclocondensation of mercaptosuccinic acid with isatin-3-imines. The 1-benzyl derivatives have been synthesized by simultaneously reacting 1-benzylisatin, substituted anilines and mercaptosuccinic acid. The structure of the products has been confirmed by X-ray diffraction measurements.