MOLECULAR-STRUCTURES OF QUINUCLIDINIC NEUROKININ ANTAGONISTS - 2-(2-PHENYLBENZYLIDENE)-3-(2-X-BENZYLAMINO) DERIVATIVES

The solid-state molecular conformations and crystal structures of thre e analogues of the CP-96,345 molecule, an important nonpeptidic SP ant agonist, namely the (+/-)-2-(3-phenylbenzilidene)-3-(2-benzylamino) qu inuclidine, the o-chloro- and the o-methoxy-derivatives, have been det ermined by X-ray diffusion analyses and refined to final R values of 0 .055, 0.045, and 0.056, respectively, All three molecules in the solid state show the same disposition of the substituents of the double bon d and differences in the conformation mainly caused by the need of rel easing intramolecular strains and/or nonbonded interactions. The obser ved molecular structures are compared to the reported solid-state stru cture of the CP-96,345 and correlated to the biological activity as NK antagonists.