The reaction of Grignard compounds with Schiff bases. I. The formation of ethylenediamine derivatives

Abstract

Highly branched RMgX and benzylidenealkylamines give diphenylethylenediamine derivs. in lieu of the expected 1-phenyl-1-alkylaminoalkane type of compds. Adding (2 hrs.) 25 g. PhCH:NEt in 50 cc. Et2O to Me3CMgCl (from 74 g. Me3CCl) in 200 cc. Et2O, refluxing the mixt. 27 hrs., decompg. it with iced NaOH, extg. with Et2O, and fractionally distg. the residue yield 8.6 g. unchanged PhCH:NEt, b12 76-7 Deg, and 15.6 g. of a yellow oil, b0.5 147-8 Deg, consisting of (EtNHCHPh)2 (I), m. 87 Deg, nD78-80 1.5203, nD100-3 1.5101 [di-HCl salt, m. 261 Deg; di-Ac deriv. (II), yellowish crystals, m. 196 Deg]. Refluxing 0.1 g. II 3 hrs. in 10 cc. 50% H2SO4 yields I. Adding (8 hrs.) in small portions 80 g. H2O to 146 g. PhCH:NEt and 50 g. Al-Hg in 1.5 l. Et2O, keeping the mixt. 40 hrs., extg. the Al2O3 with CHCl3, and evapg. the combined CHCl3-Et2O solns. give 65 g. I. The reaction mechanism is discussed.