Patent ID: 8119797

Claim:
A process for preparing a compound of the formula V wherein R 2 denotes a secondary amine —NR 2.1 R 2.2 , wherein R 2.1 and R 2.2 independently of one another are C 1-3 -alkyl or benzyl, or the group —NR 2.1 R 2.2 together forms a cyclic amine which is selected from the group consisting of morpholin-4-yl, 1-methylpiperazin-4-yl, 1-benzylpiperazin-4-yl, 1-(C 1-3 -alkylcarbonyl)-piperazin-4-yl, 1-(tert.butyloxycarbonyl)-piperazin-4-yl, 1-(benzyloxycarbonyl)-piperazin-4-yl, piperidin-1-yl and pyrrolidin-1-yl, comprising the steps of: (a) reacting 1-benzylpiperidone with an amine of the formula X H—NR 2.1 R 2.2 , (X) wherein R 2.1 and R 2.2 are defined as hereinbefore, in a solvent and in the presence of an acid; (b) reducing the product of step (a), by contact with a reducing agent to produce a product of the formula XI wherein R 2.1 and R 2.2 are defined as hereinbefore and (c) removing the benzyl protecting group from the compound of formula XI obtained in step (b) by treating the compound of formula XI with a reducing agent in a polar solvent, to yield a compound of the formula V.