PROCESS FOR PREPARING N-BENZYL-3-HYDROXY-4-SUBSTITUTED-PYRIDIN-2-(1H)-ONES

摘要

Disclosed herein is a process for preparing N-benzyl-3-hydroxypyridin-2-(1H)-ones that are substituted at the pyridine ring 4-position with a 4-carbamoylpiperazin-1-yl moiety. The process comprises A) reacting 3-hydroxypyridin-2(1 H)-one with a benzylating agent in the presence of a silylating reagent that provides at least 2 equivalents of a silyl protecting group and a proton source; to form a N-benzyl-3-hydroxypyridin-2(1 H)-one; and B) reacting the N-benzyl-3-hydroxypyridin-2(1 H)-one formed in Step (A) with a carbamoylpiperazine, in the presence of a source of formaldehyde and an acid to form the substituted N-benzyl-3-hydroxypyridin-2-(1 H)-one.