The present invention relates to allenyl amines, more specifically, .beta.-ethenylidene(substituted) ethanamines, possessing antihypertensive activity, and having the general formula ##STR1## wherein n is the integer 0, 1 or 2; each X independently is a substituent selected from the group consisting of loweralkyl, halo, --O--(loweralkyl), --S--(loweralkyl), --SO--(loweralkyl), --SO.sub.2 --(loweralkyl), CO.sub.2 R and CH.sub.2 OR, wherein R is loweralkyl and each loweralkyl group is from 1 to about 6 carbon atoms, or the pharmaceutically-acceptable addition salts thereof. These compounds are prepared by a novel reaction of a protected N,N-bis(trimethylsilyl)-4-methoxy-2-butynylamine compound with a metallo-organic compound, with subsequent removal of the silyl protecting groups to provide the desired compound.