Crystal structures ofcis andtrans 7-phenylcarbamoyl-7,9-diazabicyclo [4.3.0] nonan-8-thiones

Abstract

CI4HITN3OS, M r = 275.37, CAD4F diffractometer, Cu Kc~, T = 293K. cis: orthorhombic. Fdd2, a = 22.166(2), b = 48.948(3), and c = 5.165(1),~,; final R = 0.045 for 2519 observed reflec--tions. trans: triclinic, PT, a = 11.375(2), b = 11.388(2), c = 11.823(I)A, e~ = 110.72(I), /3 = 89.97(I) and 3' = 93.86(2)~ final R = 0.043 for 3993 observed reflections. Structures were solved with direct methods and refined by full-matrix Ibast-squares with anisotropic thermal parameters for non-H-atoms. The molecules of the studied isomers have very similar conformations. except for the obvious difference in the bicyclic system junction. Similar orientations of a flexible phenylcarbamoyl substituent results from an intramolecular hydrogen bond S--. H--N(carbamoyl). Generally, molecules of the trans form are flat and those of cis are not. The observation may be of pharmacological importance as the trans isomer is a far more potent tuberculostatic agent than the cis.