NMR AND CRYSTALLOGRAPHIC EVIDENCE FOR POLYMORPHISM OF THE L-N'-[1-(3-(PHENYL-4-PIPERAZINYL)PROPAN-2-OL)]UREA

NMR spectroscopy and single-crystal X-ray analysis have been used to c haracterize polymorphism of the racemate of the N-phenyl-N'-[1-(3-(phe nyl-4-piperazinyl)propan-2- ol)urea displaying an analgesic activity. The crystal structures of the monoclinic form, R(m) with a = 4.788(1), b = 9.432(7), c = 40.791(5) Angstrom, beta = 90.93(1)degrees, space g roup P2(1)/n, Z = 4 and of the orthorhombic form, R(o) with a = 10.948 (3), b = 8.896(3), c = 38.857(6) Angstrom, space group Pbca, Z = 8, ha ve been determined. In addition, the crystal structure of an enantiome r orthorhombic, E(o), isolated from a conglomerate, with a = 4.787(3), b = 9.461(2), c = 40.809(10) Angstrom, space group P2(1)2(1)2(1), Z = 4, has also been determined. The three conformations have been compar ed when the molecules have the same relative configurations.