SYNTHESIS OF N-BENZYL-3-(S)-(+)-(4-FLUOROPHENYL)-1,4-OXAZIN-2-ONE VIA A CRYSTALLISATION INDUCED ASYMMETRIC TRANSFORMATION

Abstract The simple and efficient preparation of enantiomerically pure N -benzyl-3-( S )-(+)-(4-fluorophenyl)-1,4-oxazin-2-one by a crystallisation induced asymmetric transformation of its racemate is reported. A key feature of this process is the use of [(1 S )-(endo,anti)]-(−)-3-bromocamphor-8-sulfonic acid as both resolving agent for the pure ( S )-enantiomer, and in situ racemising agent of the unwanted enantiomer, affording the title compound in high yield.