摘要:
The present invention is related to an improved and efficient process for preparation of (3R,4R)-(1-benzyl-4-methylpiperidin-3-yl)-methylamine which comprises: (a) N-acylation of 3-Amino-4-methyl pyridine; (b) Quarternization of 3-Acetylamino-4-methyl pyridine using benzyl halide; (c) Partial reduction of quarternized 3-Acetylamino-4-methyl pyridine by Sodium borohydride in Methanol or water; (d) Hydrolysis of partially reduced product to 1-Benzyl-4-methylpiperidin-3-one in presence of acid; (e) Reductive amination of 1-Benzyl-4-methylpiperidin-3-one using Methanolic methylamine in presence of Titanium(IV) isopropoxide in Methanol; (f) Resolution of 1-Benzyl-4-methylpiperidin-3-yl)-methylamine using Ditoluoyl (L) tartaric acid to get (3R,4R)-(1-benzyl-4-methylpiperidin-3-yl)-methylamine. The invention is also related to novel intermediates: wherein R, R′ and X are as described in the specification.