Phosphorus sulfide (P2S5) → (R)-5-(5-Bromo-2-fluoro-phenyl)-5-difluoromethyl-5,6-dihydro-2H-[1,4]oxazin-3-ylamine

Participants

Reaction Steps

To a solution of (R)-5-(5-bromo-2-fluoro-phenyl)-5-difluoromethyl-morpholin-3-one (10 g, 30.86 mmol) in CH2Cl2 (100 mL) was added P2S5 (6.86 g, 30.86 mmol) at room temperature. The resulted yellow suspension was heated to reflux for 6.5 h. The reaction mixture was filtered through a pad of silica gel (200˜300 mesh), washed with CH2Cl2 for 3 times to get a brown solution. The solvent was removed to provide the crude product as a yellow solid, which was dispersed in THF (10 mL), then 25% NH3 water solution (60 mL) was added at room temperature. 20 hours later, the reaction mixture was extracted with IPAC. The combined organic phase was washed with brine, dried over Na2SO4, filtered and concentrated to provide the title compound as a yellow solid.

Provenance & Evidence