PROCESS FOR THE PREPARATION OF S-FLUOROMETHYL-6,9-DIFLUORO-11-HYDROXY-16-METHYL-17-PROPIONYLOXY-3-OXO-ANDROSTA-1,4-DIENE-17-CARBOTHIOATE AND INTERMEDIATES

摘要

The present invention relates to a process for the preparation of steroidal 17²-carboxylic thioates. More particularly the present invention relates to a convenient and efficient synthesis of steroidal 17²-carboxylic thioates, such as fluticasone propionate I, using soluble mixed fluorides to introduce fluorine by displacing an appropriate leaving group X in compounds II resulting in selective and controlled fluorination. The present invention also relates to intermediates II and their preparation.