Chloroacetyl chloride → 7-bromo-3,4-dihydro-2H-1,4-benzoxazin-3-one

Participants

Reaction Conditions

Reaction Steps

To a mixture of 2-amino-5-bromophenol (51.3 g, 273 mmol) and NaHCO3 (68.8 g, 819 mmol) in water (200 mL) and DME (200 mL) was added 2-chloroacetyl chloride (46.2 g, 409 mmol) at 0° C. and the reaction mixture was stirred at 15° C. for 0.5 h then heated at 80° C. for 18 h. The reaction mixture was cooled to ambient temperature. The precipitate was collected by suction, washed with water and dried in vacuo to give 7-bromo-4H-benzo[1,4]oxazin-3-one (59.7 g, 96%) as a brown solid. 1H NMR (400 MHz, DMSO-d6) δ 10.83 (br s, 1H), 7.17 (s, 1H), 7.12 (d, J=8.4 Hz, 1H), 6.83 (d, J=8.4 Hz, 1H), 4.59 (s, 2H).

Provenance & Evidence