NEW MATERIAL:The compound of formula I [R1 is H or lower alkoxycarbonyl; R2 is lower alkoxycarbonyl or R1 and R2 together form a group of formula II; R3 and R4 are lower alkoxy; the ring A forms a (substituted) S-containing or N-containing heterocyclic group] or its salt.
EXAMPLE: 4-Hydroxy-5,6-bis(methoxycarbonyl)-7-(3,4-dimethoxyphenyl) benzo[b]thiophene.
USE: A drug. It has excellent antithrombogenic action, lowers total cholesterol in blood, increases HDL-cholesterol level, has low toxicity and is free from side effect such as hepatic dysfunction.
PREPARATION: A compound of formula I wherein R2 is R21 can be produced by reacting an acetylene compound of formula III (R11=R1; R21 is lower alkoxycarbonyl) with a compound of formula IV (R5 is H, alkyl or acyl) or a di(lower alkyl)acetal compound of formula V (R6 is lower alkyl).
TAKASHIMA KOKI
Next Patent: N-PIPERIDYLLACTAM DICARBOXYLIC ACID ESTER