vic-Enediamines. Reaction of some tert-β-dichloroalkylamines with lithium-dialkylamides

Abstract

1,2-Bisdialkylaminoethylenes (vinylene amines)(3) are prepared from tertiary-β-dichloroethylamines (1) by reaction with lithium-s-amides. It is shown that formation of (3) under the reaction conditions depends on the existence of 1,1,2-trisdialkylaminoalkane intermediates (2). This in turn depends on prior formation of a carbanion which cannot exist if β-hydrogen in (1) is replaced by an alkyl group. Instead, the starting β-dichloroalkylamines (7) are reduced to monochloro-derivatives. 2-(1,1-Dichloropropyl)diethylamine (9) yields 1,1-bisdiethylaminopropene (10) by reaction with lithium diethylamide. The rearrangement involved is discussed.

The chemistry of vinyleneamines is that expected of enamines and includes alkylation, halogenation, reaction with a nitrile oxide, and with methyl acetylenedicarboxylate. Vinyleneamines undergo transamination.