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

C₁₄H₁₇N₃OS,M_r+275.37, CAD4F diffractometer. CuK,T+293K.cis: orthorhombic, Fdd2,a+22.166(2),b+48.948(3), andc+5.165(1)Å: finalR+0.045 for 2519 observed reflections,trans: triclinic,,a+11.375(2),b+11.388(2),c+11.823(1)Å, =110.72(1), =89.97(1) and =93.86(2)^o; final R=0.043 for 3993 observed reflections. Structures were wolved with direct methods and refined by full-matrix least-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 thetrans form are flat and those ofcis are not. The observation may be of pharmacological importance as thetrans isomer is a far more potent tuberculostatic agent than thecis.