Procedure for the preparation of an intermediate for mu opiate receptor antagonists

摘要

A process for preparing a compound of formula 1, which has the chemical name 3-endo- (8-azabicyclo [3.2.1] oct-3-yl) benzamide, or a salt thereof: ** Formula ** the process it comprises hydrogenating a compound of formula 2, which has the chemical name 3- (8-azabicyclo [3.2.1] oct-2-en-3-yl) benzamide: ** Formula ** or an acid salt thereof, in the presence of a palladium metal catalyst and, when the compound of formula 2 is in the form of a free base, in the presence of an acid, to provide a compound of formula 1 or a salt thereof, wherein the compound of formula 2 or acid salt thereof has been prepared by deprotecting a compound of formula 3: wherein: P 1 is tert-butoxycarbonyl or p-methoxybenzyloxycarbonyl.