INTERMEDIATES FOR PREPARATION OF AN INHIBITOR OF PHOSPHODIESTERASE TYPE 5

摘要

Boronic compounds of formula II and preparation method thereof, where Y1and Y2 are selected from hydroxyl, (C1-C4) alcoxyl and phenoxyl optionally replaced by one or two radicals independently selected from (C1-C4) alkyl and (C1-C4) alcoxyl; or alternatively Y1 and Y2 together with the atom of boron can form a cyclical system. Method for preparation of sildenafil by reaction of an intermediate of formula II with an intermediate with formula III, where X3 is a salient group and R1 is selected from H and (C1-C4) alkyl.