This application relates to a compound of Formula (I) or a pharmaceutically acceptable salt thereof, pharmaceutical compositions thereof, and its use as an inhibitor of the NK-1 subtype of tachykinin receptors, as well as a process for its preparation and intermediates therefor. (I) wherein: D is a C.sub.1-C.sub.3 alkane-diyl; R.sup.1 is phenyl, which is optionally substituted with one to three substitutents independently selected from the group consisting of halo, C.sub.1-C.sub.4 alkyl, C.sub.1-C.sub.4 alkoxy, cyano, difluoromethyl, trifluoromethyl, and trifluoromethoxy; R.sup.4 is a radical selected from the group consisting of: (IA), (IB), (IC), (ID), (IE), (IF), (IG), (IH) ##STR00001##