Kinetic resolution of racemic 3-tert-butyl-3,4-dihydro-2H-[1,4]benzoxazine via acylation with chiral acyl chlorides

A comparative study of the kinetic resolution of racemic 3-tert-butyl-3,4-dihydro-2H-[1,4]-benzoxazine through the acylation by various chiral acyl chlorides was carried out. A preparative method for obtaining enantiomerically pure (S)-3-tert-butyl-3,4-dihydro-2H-[1,4]benzoxazine can be based on the acylation with N-phthaloyl-(S)-phenylalanyl or (R)-2-phenoxypropionyl chlorides, followed by the acid hydrolysis of the corresponding diastereomerically pure amides.