Reduction of Organic Compounds with Sodium Borohydride-Transition Metal Salt System. III. : Preparation of 2-Aminomethyl-1, 1-diphenyl-1-butene

Abstract

Preparative methods for 2-aminomethyl-1, 1-diphenyl-1-butene (I), a hypertensive drug, were investigated. The following three-step method was suggested to be the most suitable for the preparation of I. The first process is to obtain 2-cyano-1, 1-diphenyl-1-butanol (II) by condensation of butyronitrile and benzophenone in the presense of sodium hydride (molar ratio, 1 : 2 : 2) at 90°. The second is the reduction of II by sodium borohydride-CoCl₂ system (molar ratio, II : NaBH₄ : CoCl₂=1 : 10 : 2) in MeOH at 20° to 2-aminomethyl-1, 1-diphenyl-1-butanol (III), and the final step is the dehydration of III to I in a mixture of acetic acid and conc. hydrochloric acid (20 : 1).