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 17β-carboxylic thioates. More particularly the present invention relates to a convenient and efficient synthesis of steroidal 17β-carboxylic 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 fluorination. The present invention also relates to intermediates formula (II) and their preparation.