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

Participants

Reaction Steps

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

Provenance & Evidence