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 steroid al 17.beta.-carboxylic thioates. More particularly the present invention rel ates to a convenient and efficient synthesis of steroidal 17.beta.-carboxyli c thioates, such as fluticasone propionate formula (I), using soluble mixed fluorides to introduce fluorine by displacing an appropriate leaving group X in compounds formula (II) resulting in selective and controlled fluorinatio n. The present invention also relates to intermediates formula (II) and thei r preparation.