PROCESS FOR PREPARING PYRAZOLOPYRIMIDINONE DERIVATIVES FOR TREATMENT OF IMPOTENCE

摘要

PURPOSE: Provided is a process for preparing pyrazolopyrimidinone derivatives, their pharmaceutically acceptable salts which are used for the treatment of impotence, in high yields. CONSTITUTION: The method comprises the steps of: chlorosulfonating pyrazole amide compound of the formula(2) to prepare a compound of the formula(3); aminating the compound of the formula(3) with primary amine to prepare a compound of the formula(4); and cyclizing the compound of the formula(4) to obtain a compound of the formula(4).