PROCESS FOR PREPARATION OF PYRAZOLO[4,3-D]PYRIMIDIN-7-ONES AND INTERMEDIATES THEREOF

摘要

A process is provided for the preparation of a compound of formulae (IA) (sidenafil/ ViagraTM TM) and (IB) (see formula IA, IB) comprising reacting a compound of formula (IIA) and (IIB) respectively in th e presence of -OR, wherein R in the case of formation of compound (IA) is CH2C H3 and R in the case of formation of compound (IB) is CH2CH2CH3, where X is a leaving group: (see formula IIA, IIB)