1-{1-[4-(4-Fluorophenyl)-4-oxobutyl]-1,2,3,6-tetrahydro-4-pyridyl}-1,3-dihydro-2H-benzimidazol-2-one dihydrate (Dehydrobenzperidol®)

Abstract

C=H=FN302.2H20 , M~ = 415.45, mono- clinic, P21/n, a = 9.693(2), b = 10.811 (3), c = 20-442 (5) /k, fl= 79.16(2) ° , V= 2104 (1) /k3, Dm = 1.32, D = 1.31 Mg m --~, Z = 4, 2(Cu K-) = 1.5418 X, /J(Cu Ka) = 0.82 mm-~; F(000) = 880, final conventional R = 6.2% for 1421 reflections with (sin 0/2),,,,~ = 0.459/k -~. Owing to the presence of two water molecules an extensive network of hydrogen bonds is formed. Introduction. The title compound, also called droperidol, is a potent neuroleptic. Crystals were grown at room temperature by slow evaporation from a water-methanol solution. The cell dimensions were obtained from a least- squares fit to the setting angles of 23 reflections. Intensity measurements were made on a Syntex P2~ diffractometer with graphite-monochromated Cu Ka radiation. During the collection of data, three reference reflections (measured every 50 reflections) showed a nearly linear intensity decrease of approximately 30% with time (0-20 scan technique). Intensities were measured for all independent reflections (1912) with 20 3-0o(I,~L)I and used in the refinement. The data were corrected for Lorentz-polarization effects, but not for absorption. The structure was solved by direct methods using MULTAN (Main, Woolfson, Lessinger, Germain & Declercq, 1974). All non-hydrogen atoms were located in the resultant E map. Refinement of the positional and anisotropic thermal parameters of the 17 non- hydrogen atoms by block-diagonal least-squares methods (CRYLSQ link of the XRAY system; Stewart, Machin, Dickinson, Ammon, Heck & Flack, 1976) resulted in R = 9-7%. The H atoms were then located from a difference synthesis and were included as a fixed-atom contribution with the overall tempera- ture factor. Further refinement converged at R =