The crystal and molecular structure of chlorpropamide

Abstract

Chlorpropamide, C10H13N2O3SCl, forms orthorhombic crystals of space group P212121 with a 9.066±0.004, b=5.218±0.003, c=26. 604±0.008 A, and four molecules per cell. Three dimensional photographic data were collected with Mo-Kα radiation. The structure was determined using Patterson, Fourier and Difference syntheses methods and refined by the block-diagonal least-squares methods with anisotropic thermal parameters for all nonhydrogen atoms and isotropic thermal parameters for all hydrogen atoms. The final R value was 0.10 for the 1823 observed independent reflections. The dihedral angle between the planes through the benzene ring and the urea group is 99° The conformational angle formed by the projection of the S−C(1) with that of N(1)−C(7) when the projection is taken along the S−N(1) bond is 76°. The molecule appears to form with neighbouring molecules two hydrogen bonds, N(1)−H…0(3) and N(2)−H…O(2) of lengths 2.774 and 2.954A respectively related by screw diads parallel to the a axis. Adjacent molecules parallel to b and c axis are bound together by van der Waals forces.