Synthesis of Atropisomeric Quinazolin-4-one Derivatives Based on Remote H/D and C/C Discrimination.

Both enantiomers of 2-ethylquinazolin-4-ones bearing -CHO/CDO and CHO/CHO phenyl groups at the N3 position were prepared. These are isotopic atropisomeric compounds based on a remote and conformationally flexible H/D and C/C discrimination, and it was found that a CHCl solution of -CHO/CDO derivative shows a slight specific optical rotation. Furthermore, diastereomeric quinazolinone derivatives bearing a chiral carbon were prepared, and their stereochemical purities and rotational stability as well as the isotopic atropisomerism were verified by H NMR and chiral high-performance liquid chromatography (HPLC) analyses.