Ammonium Chloride → 1-(3,5-difluorophenyl)-2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methylpropan-1-ol

Participants

Reaction Steps

3,5-Difluorobromobenzene (2.9 g) was added to a suspension of magnesium (0.41 g) in tetrahydrofuran, under an inert atmosphere at 20° C., slowly, to initiate reaction, then at a rate to maintain gentle reflux. After refluxing for 1 hour, the mixture was added to a solution of 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methylpropionaldehyde (2.59 g) in tetrahydrofuran at -78° C. The solution was warmed to ambient temperature and stirred for 18 hours. Ammonium chloride and ethyl acetate were added and the organic phase dried (magnesium sulphate) and evaporated to give 1-(3,5-difluorophenyl)-2-methyl-2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-propan-1-ol (1.32 g), m.p. 87.6-89.0° C.

Provenance & Evidence