Optically active alpha-substd. benzylamine derivs. racemisation - by liq. phase hydrogenation in presence of hydrogenation catalyst

摘要

In a new process for the prodn. of racemic mixts. from optically active benzylamine derivs. of formula (I) (where R1 is alkyl2, aralkyl or opt. substd. aryl; and R is H, alkyl or alkoxy) the optically active (I) is treated with H2 in the presence of a hydrogenation catalyst at elevated temp. in the liq. phase. Optically active cpds. (I) are useful as intermediates and reagents, e.g. in the prodn. of optically active pharmaceuticals. The new process enables unwanted isomers of (I) to be converted into racemates from which further yields of the wanted isomer can be obtd. by optical resolution. In many cases the hydrogenation can be carried out at normal pressure.