Enzymatic process of making alpha 1a adrenergic receptor antagonists using protease

Abstract

This invention relates to crystalline pharmaceutically acceptable salts of an alpha 1a adrenergic receptor antagonist, Compound A, which are useful in the treatment of benign prostatic hyperplasia. Pharmaceutical compositions employing the crystalline salts, and processes for making and using the crystalline salts and pharmaceutical compositions of Compound A are also disclosed. This invention further relates to a process for obtaining enantiomerically pure intermediate useful for the synthesis of end product alpha 1a adrenergic receptor antagonists. The end product compounds are useful for the treatment of benign prostatic hyperplasia and for relaxing lower urinary tract tissue. The invention also relates to a process for preparing a class of dihydropyrimidinone compounds of which Compound A is a member, wherein the process involves deprotonating a dihydropyrimidinone compound and then coupling the deprotonated derivative with a primary amine.