Reaction between phenyl isocyanate and N-bis (2-chloroethyl) amine in cold diethyl ether solution yields N-phenyl-N'-bis (2-chloroethyl) urea. The urea was found to rearrange in ethanol solution or upon warming to, respectively, 2-(N-phenylimino)-3-(2'-chloroethyl) oxazolidine hydrochloride and 1-phenyl-2-oxo-3-(2'-chloroethyl) imidazolidine. Infrared spectral studies, augmented by mass and proton magnetic resonance determinations ...