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.