Molecular and crystal structure of 4-dichloromethylene-5-benzoyl-6-phenyl-perhydropyrimidin-2-one and its N(1)-substituted analogue

A single crystal X-ray diffraction analysis of 4-dichloromethylene-5-benzoyl-6-phenyl-perhydropyrimidin-2-one and its functionally substituted analogue with a methylcarbonyl substituent at the N(1) atom in the heterocycle is performed. The molecules of both compounds have two chiral centers. Only rel(S,R)-diastereomers are found in the crystals (the crystals are centrosymmetric). In the 4-dichloromethylene-5-benzoyl-6-phenyl-perhydropyrimidin-2-one molecule the heterocycle is in the С(6)-sofa conformation, whereas the molecule of the substituted analogue has a distorted boat conformation. Due to classical hydrogen bonds there are 1D and 0D supramolecular structures in the crystals of the studied compounds. Interactions of the С–H?O type, which only stabilize the structure of already formed associates rather than link the chains or dimers with each other, are also noted.