Novel synthesis process of trans-4-methylcyclohexylamine base and derived salts of trans-4-methylcyclohexylamine hydrochloride or pivalate usable as intermediates in the preparation of glimepiride antidiabetic

摘要

In the present invention, there is disclosed a process for preparing trans-4-methylcyclohexylamine of the general formula V, optionally a corresponding trans-4-methylcyclohexylamine hydrochloride of the general formula VIII or pivalate of the general formula VII exhibiting high content of trans-isomer, wherein the preparation process is characterized by the following steps: a) subjecting a Schiff's base of the general formula to isomerization by treating thereof with a strong base in a solvent being selected from the group consisting of aliphatic ethers, cyclic ethers, dialkylsulfoxides, or dialkyl sulfones to obtain an isomeric compound of the general formula X; b) subjecting the isomeric compound of the general formula to acid hydrolysis by treating thereof with a mineral acid to obtain a corresponding salt of trans-4-methylcyclohexylamine; c) optionally converting the obtained salt of trans-4-methylcyclohexylamine to a base of the general formula V or hydrochloride of the general formula VIII pivalate of the general formula VII. The compounds of the general formulae V, VII or VIII are used for preparing glimepiride.