6-Bromo-2H-pyrido[3,2-B][1,4]oxazin-3(4H)-one → 6-bromo-2H,3H,4H-pyrido(3,2-b)(1,4)oxazine

Temperature

70 °C

6-Bromo-4H-pyrido[3,2-b][1,4]oxazin-3-one (1.35 g, 5.89 mmol) was dissolved in THF (40 mL). Boranedimethylsulphide complex (2.0 M in THF, 5.89 mL, 11.79 mmol) was added and the resulting mixture heated to 70° C. under nitrogen for 15 minutes. Next, the reaction mixture was cooled to room temperature, quenched with methanol (˜5 mL), and then dried under vacuum to obtain a white solid. The crude material was dissolved in dichloromethane and washed with H2O. The aqueous phase was discarded and the organic phase was dried under vacuum to give 6-bromo-3,4-dihydro-2H-pyrido[3,2-b][1,4]oxazine. Yield: 1.1 g (87%). LCMS (ESI): calc. C7H7BrN2O=214, 216; obs. M+H=215, 217.

1. temperatureNext, the reaction mixture was cooled to room temperature
2. customquenched with methanol (˜5 mL)
3. customdried under vacuum
4. customto obtain a white solid
5. washwashed with H2O
6. customthe organic phase was dried under vacuum

ORD record

ord-fe9d6a9f177c4a8d9a4c8fe8a8c3cdcb

Source dataset

uspto-grants-2016_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09394315B2