The effect of manganous salts on the reaction of Schiff bases with Grignard reagents

Abstract

Benzylidenebutylamine (I), PhCH: NBu, with filtered iso-PrMgI (II), made from high purity Mg, gave 17.7% alpha -phenyl-alpha -butylamino-beta -methylpropane (III) and 2.8% PhCH2NBu (IV). In the presence of 5 mole-% anhyd. MnCl2, the dimer N,N'-dibutyl-alpha ,alpha '-diphenylethylenediamine (V) was formed, 11% racemic mixt. and 11.8% meso form. III and IV were formed in 5.2% and 3.4% yield, resp. When II was prepd. from ordinary Mg ribbon, V was also formed.