Preparing pyrazolopyrimidinone derivatives for the treatment of impotence

摘要

The present invention relates to the method for preparing pyrazolopyrimidinone derivatives and their pharmaceutically acceptable salts having efficacy on the treatment of impotence, one of male sexual dysfunctions. The method according to the present invention comprises the steps of chlorosufonation the pyrazolamide, followed by amination with amine and intramolecular cyclization. The method provides the pyrazolopyrimidinone derivatives and their pharmaceutically acceptable salts with high yield and in an economic manner.