Class of spiro-linked pyrrolidine-2,5-diones

摘要

The invention provides a novel spiro-linked pyrrolidine-2,5-dione of the formula; <IMAGE> [I] wherein X1 and X2 each independently represent a hydrogen, a halogen atom, a lower alkyl or lower alkoxy group; Y is a methylene group, oxygen or sulfur atom; R1, R2, R3 and R4 each independently represent a hydrogen atom, a lower alkyl group or forming a benzene ring together with their adjacent carbon atoms; the base salts thereof with pharmaceutically acceptable cations, and processes for their manufactures. The compounds of formula [I] useful as aldose reductase inhibitors and as therapeutic agents for treatment of chronic diabetic complications are also disclosed.