2,2,2-Trifluoro-1-methoxyethanol → 6-bromo-4,4-dimethyl-2-(trifluoromethyl)-1,4-dihydro-2H-3,1-benzoxazine

Participants

Reaction Conditions

Reaction Steps

A mixture of 2-(2-amino-5-bromo-phenyl)-propan-2-ol (5 g, 21.7 mmol), trifluoroacetaldehyde methyl hemiacetal (5 mL), and magnesium sulfate (10 g) in toluene (75 mL) was heated at 80° C. under nitrogen. After disappearance of the starting material, the reaction was filtered through a pad of silica gel and the filtrate dried over sodium sulfate and concentrated to give 6-bromo-4,4-dimethyl-2-(trifluoromethyl)-1,4-dihydro-2H-3,1-benzoxazine as an amorphous solid: 1H-NMR (DMSO-d6) δ 7.31 (d, 1H, J=1.99 Hz), 7.19 (dd, 1H, J=8.73, 2.38 Hz), 6.88 (s, 1H), 6.74 (d, 1H, J=8.33 Hz), 5.32 (m, 1H), 1.52 (s, 6H).

Provenance & Evidence