Process for the preparation of 17-esters of 9 alpha , 21-dihalo-pregnane-11 beta , 17 alpha -diol-20-ones

摘要

The invention provides an improved process for the preparation of 17-esters of 9 alpha ,21 -dihalo-pregnane-11 beta ,17 alpha -diol-20-ones, and in particular for the preparation of 17-esters of anti-inflammatory steroids according to the following scheme: <IMAGE> <IMAGE> <IMAGE> +TR <IMAGE> wherein RCO, R1, X, Y and the dotted line are as defined in the specification. The novel process is especially suitable for the preparation of Mometasone Furoate.