Synthesis of Isotopic Atropisomers Based on 12C/13C Discrimination

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.