Chloroacetyl chloride → 6-Bromo-2H-1,4-benzoxazin-3(4H)-one

Participants

Reaction Conditions

Reaction Steps

NEt3 (2.4 mL, 17 mmol) was added to 2-amino-4-bromophenol (2.5 g, 13 mmol) in THF (80 mL). The reaction mixture was cooled to 0° C., chloroacetyl chloride (1.12 mL, 14 mmol) was added portionwise and then stirred at 0° C. for 10 minutes before being allowed to warm to r.t. and stirred for a further 2 h. The reaction mixture was cooled to 0° C. and NaH (1.05 g, 60% dispersion in oil, 26 mmol) was added portionwise. The reaction mixture was stirred at 0° C. for 20 minutes then at r.t. for 2 h before being quenched with water (20 mL). The solvent was removed in vacuo and the resulting mixture diluted with water (100 mL). The precipitate was filtered, washed with water (3×50 mL) and dried in vacuo to give the title compound (2.14 g, 70%) as a beige solid. δH (DMSO-d6) 10.81 (1H, br. s), 7.08 (1H, dd, J 8.5 and J 2.3 Hz), 7.02 (1H, d, J 2.3 Hz), 6.92 (1H, d, J 8.5 Hz), 4.60 (2H, s).

Provenance & Evidence