A. Carpy

Structure de la (dichloro-2,6 phényl)-2 méthyl-1 guanidine base et chlorhydrate; un analogue ouvert de la clonidine

CaH9C12N 3 is a ring-opened analogue of clonidine which exhibits hypotensive activity. Crystals of the free base (M r = 218.1) and hydrochloride.½H20 (M r = 263.5) have been isolated and studied by X-ray single-crystal diffraction methods. Crystals of the free base are monoclinic, space group P2~/c, with a = 7.911(2), b = 15.569(1), c = 9.130(3)A, fl = 67.76 (2) °, Z = 4, D x = 1.39 Mg m -a, F(000) = 448, whereas crystals of the hydrated hydrochloride, CsH~0C12N+.CI-.½H2 O, are monoclinic, space group C2/c, with a = 17.887 (2), b = 12.775 (1), c = 13.293(1)A, fl= 52.60(1)°,Z=8, Dx= 1.45Mg m -3, F(000) = 1120. Both structures were solved by direct methods and the atomic parameters were refined by a least-squares procedure, giving final R factors of 0.046 and 0.056 for 1365 and 1902 structure amplitudes respectively. The free base occurs as a dimer. The C1- and H20 are involved in hydrogen