Abstract Steric interactions between aryl and heterocyclic moieties in 2-substituted-2, 3- dihydro-3-o-tolyl (chlorophenyl)-4 (1H)-quinazolinones 1a-j produce sufficient restriction to rotation about the aryl C [BOND] N bond that the presence of torsional isomers may be detected at room temperature. Diastereomeric population and free energy of activation for rotation have been calculated by 1 H nmr spectra. Probably due to a preferred axial ...
