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

Temperature

0 °C

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).

1. temperatureto warm to r.t.
2. stirringstirred for a further 2 h
3. temperatureThe reaction mixture was cooled to 0° C.
4. stirringThe reaction mixture was stirred at 0° C. for 20 minutes
5. customat r.t. for 2 h before being quenched with water (20 mL)
6. customThe solvent was removed in vacuo
7. additionthe resulting mixture diluted with water (100 mL)
8. filtrationThe precipitate was filtered
9. washwashed with water (3×50 mL)
10. customdried in vacuo

ORD record

ord-8f41b05d23f247029768681585b23dd4

Source dataset

uspto-grants-2012_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08242116B2