STRUCTURE OF THE BETA-BLOCKER VASODILATOR AGENT PRIZIDILOL, O)-2-HYDROXYPROPOXY]PHENYL)-3-PYRIDAZINYLHYDRAZINE HEMISULFATE MONOHYDRATE

Prizidilol, a compound combining vasodilator and beta-blocker function alities in the same molecule, has been synthesized and characterized b y Smith Kline and French Research Ltd. Crystal data: C17H25N5O2.1/2H2S O4.H2O, M(r) = 398.47, orthorhombic, a = 10.722 (2), b = 11.635 (6), c = 34.105 (3) angstrom, V = 4254.61 angstrom3, Pbnm (non-standard form of Pnma) (D2h16, No. 62), Z = 8, F(000) = 1704, D(x) = 1.244 Mg m-3, mu(Cu Kalpha) = 11.673 cm-1, R = 0.064 for 2432 independent reflection s with I > 3sigma(I). Prizidilol shows strong conformational similarit ies to propranolol and is protonated at the secondary amine. The 6-phe nyl-3-hydrazinopyridazine residue is not planar. The hydroxy group at the asymmetric carbon is disordered so that both enantiomers are found at each molecular site. The sulfate ions and disordered water molecul es lie in the crystallographic mirror plane.