N–C axially chiral 3-(2-trideuteriomethyl-4,6-dimethylphenyl)-2-ethylquinazolin-4-ones and 3-(2-trideuteriomethyl-4,6-dimethylphenyl)-2-(1-phenylpropan-2-yl)­quinazolin-4-ones were prepared in high enantio- and diastereomeric purities (98% ee). These quinazolinone derivatives are isotopic atropisomers based on ortho-CH3/CD3 discrimination and were revealed to possess a slight optical rotation and high rotational stability.

Racemic and optically active 3-(2-deuteriophenyl)-2-(1-phenylpropan-2-yl)­quinazoline-4-thiones were prepared. The nuclear magnetic resonance spectra clearly show that they exist as a 1:1 mixture of diastereomers due to the isotopic atropisomerism based on ortho-H/D discrimination (N–C axial chirality) and a chiral carbon.

Quinazolin-4-one derivatives possessing an isotopic atropisomerism (isotopic N–C axial chirality) based on ortho-12CH3/13CH3 discrimination were prepared. The diastereomeric quinazolin-4-ones bearing an asymmetric carbon as well as an isotopic atropisomerism were clearly discriminated by 1H and 13C NMR spectra and revealed to possess high rotational stability and stereochemical purity.