CONFORMATION OF ACYLUREAS - SOLVENT POLARITY DEPENDENT SPECIFIC ROTATION AND THE FORMATION OF MOLECULAR-COMPLEXES WITH SOLVENT MOLECULES POSSESSING A CARBONYL OR EPOXY FUNCTIONALITY

In order to elucidate the conformation of acylurea which possesses int ramolecular hydrogen bonding between the carbonyl and NH groups, the r elation between solvent polarity [ET(30)] and specific rotation of 2,6 -bis(ureidocarbonyl)naphthalene 1 was examined. A good Linear relation ship was observed, except for solvents with a carbonyl functionality. Some of these solvents formed molecular complexes with 1 (molar ratio of 1:solvent, 1:2). Single crystal X-ray diffraction analysis of the m olecular complex of 1 with ethyl acetate disclosed that the intramolec ular hydrogen bonding was absent due to the intermolecular hyrdrogen b onding with ethyl acetate. In contrast, 2,4'-bis(ureidocarbonyl)benzop henone 2 formed 1:1 complexes with carbonyl compounds, and the bulkier 2,6-bis(ureidocarbonyl)naphthalene 3 could not form complexes with th em.