A PROCESS FOR THE PREPARATION OF 1-[[3-(6,7-DIHYDRO-1-METHYL-7-OXO-3-PROPYL-1H-PYRAZOLO[4,3-D]PYRIMIDINE-5-YL)-4-ETHOXYPHENYL]SULFONYL]-4-METHYLPIPERAZINE AND INTERMEDIARY COMPOUNDS

摘要

A process is provided for the preparation of a compound of formula (IA) (sidenafil/ViagraTM) comprising reacting a compound of formula (IIA) in the presence of -OR, wherein R in the case of formation of compound (IA) is cì2cì3 where X is a leaving group , (IA) (IIA).