PURPOSE: To obtain a new intermediate which is important to synthesize the compd. of the title as a testosterone 5α-reductase inhibitor useful for treatment for acne, seborrhea, female hirsutisum and prostatomegaly.
CONSTITUTION: This compd. is expressed by formula I (R2 is thiopyridyl; R3 is 1 to 4C alkoxycarbonyl, 1 to 4C alkoxy or trifluoromethylsulfonyloxy), and for example, the compd. is 17β-(2-pyridylthiocarbonyl)-androsta-3,5-diene- carboxylic acid methyl ester. The compd. of the purpose is obtd. by treating a steroid acid expressed by formula II with trifluoromethylsulfonyl anhydride and tertiary amine, treating the obtd. product with 2,2-dithiopyridyl and triphenylphosphine(TPP) to obtain a compd. expressed by formula III, allowing the obtd. compd. to react with Grignard reagent to obtain a compd. expressed by formula IV (R is same as R3), allowing the obtd. compd. to react with TPP in the presence of a palladium acetate catalyst and a tertiary org. amine, and then finally treating the obtd. product with NaOH.
RICHIYAADO ERU TORUMAN
GUURU EFU PATERU
