NEW MATERIAL:The compound of formula I [R1 is H, CH2COOH or CH2CO-A- OH (A is amino acid residue); R2 is R1 except for H; X and Y are H or halogen; R1O, R2O, X and Y are substituted to arbitrary positions in the 4, 5, 6 and 7 positions of the benzofuran ring] and its salt.
EXAMPLE: Bis(7-ethoxycarbonylmethoxy-2-benzofuranyl)ketone.
USE: Pharmaceuticals. It has strong aldose-reductase inhibiting activity, and is useful also for the prevention and remedy of retinopathy of diabetes mellitus caused by the metabolic disorder in polyol pathway, and circulatory diseases such as thrombosis.
PREPARATION: The compound of formula I can be prepared by hydrolyzing the novel compound of formula II [R3 is H, etc.; R4 is CH2COOR5 (R5 is 1W4C straight- or branched-chain alkyl, etc.] with NaOH, etc. by conventional method.
OOISHI YOSHITAKA
TAKEHISA YOSHITAKA
YAJIMA MOTOYUKI
KUROKAWA SHIGEKI
KAJIKAWA NORIO
