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

C14H17N3OS,M r+275.37, CAD4F diffractometer. CuKα,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, $$P\bar 1$$ ,a+11.375(2),b+11.388(2),c+11.823(1)Å, α=110.72(1), β=89.97(1) and γ=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.