PROCESS FOR PREPARATION OF 6-ALPHA,9-ALPHA-DIFLUORO-17-ALPHA-(2-FURANYLCARBONYL)OXY-11-BETA-HYDROXY-16-ALPHA-METHYL-3-OXO-ANDROSTA-1,4-DIENE-17-BETA-CARBOTHIOIC ACID S-FLUOROMETHYL

摘要

PROBLEM TO BE SOLVED: To provide a novel process for preparing a compound of the formula (I).SOLUTION: A process comprises converting 6-alpha,9-alpha-difluoro-17-alpha-[(2-furanyl carbonyl)oxy]-11-beta-hydroxy-16-alpha-methyl-3-oxo-androsta-1,4-diene-17-beta-carbothioic acid S-furoyl ester via 6-alpha,9-alpha-difluoro-17-alpha-[(2-furanyl carbonyl)oxy]-11-beta-hydroxy-16-alpha-methyl-3-oxo-androsta-1,4-diene-17-beta-carbothioic acid or a salt thereof to a compound of the formula (I) without isolating any intermediates.