METHOD OF PRODUCING INTERNAL SALTS OF NAPHTHALENYLTHIAZOLE DERIVATIVES

摘要

Disclosed herein are new aldose reductase inhibitors of the formula wherein R is wherein R1 is lower alkyl; R2 is halo and R3 is hydrogen, or R2 and R3 each is a substituent at positions 3, 4, 5 or 6 of the naphthalene ring selected from the group consisting of lower alkoxy, trihalomethyl, and halo; and R4 is lower alkyl. The derivatives are useful for treating or preventing diabetic complications.