INTERMEDIATES FOR PREPARATION OF AN INHIBITOR OF PHOSPHODIESTERASE TYPE 5

摘要

Boronic compounds of formula II and the process for their preparation, wherein Y 1 and Y 2 are selected from hydroxyl, (C 1 -C 4 )alcoxyl and phenoxyl optionally substituted with one or two radicals independently selected from (C 1 -C 4 )alkyl and (C 1 -C 4 )alcoxyl; or alternatively Y 1 and Y 2 together with the boron atom can form a cyclic system. Process for the preparation of Sildenafil by reaction of a intermediate of formula II with a intermediate of formula III, wherein X 3 is a leaving group and R 1 is selected from H and (C 1 -C 4 )alkyl.