PROCESS FOR PRODUCING INHIBITORS OF ALDOSE-REDUCTASE

摘要

The present invention relates to an aldose reductase inhibitor having the following formula: R1 is a hydrogen atom or -A-COOR5 (A is an alkylene group having 1 to 4 carbon atoms and R5 is a hydrogen atom or a lower alkyl group), and R2, R3 and R4 are the same as or different from each other and selected from the group consisting of a hydrogen atom, a hydroxy group, a halogen atom, a carboxyl group, an alkyl group, an amide group, an amino group, an alkoxy group, an aryl group, an aryloxy group, an alkylthio group, an alkylsulfinyl group, an alkylsulfonyl group, a nitro group, -NHCOCOOR6 (R6 is a hydrogen atom or a lower alkyl group), a mono- or dialkylaminosulfonyl group, and a residual group having the following formula: (A and R5 are the same as in the above). The compounds defined in the above are excellent in aldose reductase inhibitory activity and low in toxicity. Therefore, those compounds are useful as a preventive agent and/or a remedy for diabetic complications such as neuropathy, retinopathy, nephropathy, cataracts and keratopathy.