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

Abstract

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.