BENZOFURAN DERIVATIVE, PRODUCTION THEREOF AND REMEDY FOR DIABETIC COMPLICATION CONTAINING SAID DERIVATIVE AS ACTIVE INGREDIENT

摘要

NEW MATERIAL:A compound expressed by formula I (R1 is H, benzyl or 1-3C alkyl; R2 is H or 1-3C alkyl; R3 is acetyl, ethyl, carboxyl, etc.; R4 is H, OH, 1-6C alkyl, 1-9C alkoxy, NO2, acetamino, etc.; R5 is H or may link to R4 to form methylenedioxy; n is 1 or 2) or a salt thereof. EXAMPLE:2-Acetyl-4-(N-carboxymethylsulfamoyl)-7-methoxybenzofuran. USE:A remedy for diabetic complications having powerful inhibitory activity against aldose reductase and further powerful inhibitory activity against blood platelet agglutination. PREPARATION:A compound expressed by formula II (X is halogen; R4 is H, alkyl, NO2, etc.; R5 is acetyl, alkoxycarbonyl, etc.) is reacted with an amine compound expressed by formula III (R9 is alkyl) to give an ester, which is then hydrolyzed to afford the aimed compound expressed by formula I.