Potassium Carbonate → 7-bromo-2,2-dimethyl-2H,3H,4H-pyrido(3,2-b)(1,4)oxazin-3-one

To a mixture of 2-amino-5-bromopyridin-3-ol (0.500 g, 2.64 mmol) and K2CO3 (1.09 g, 7.93 mmol) in acetone (11.0 mL) was added ethyl bromoisobutyrate (0.50 mL, 3.4 mmol). The solution was stirred under N2 for 18 h and then heated to reflux. After 18 h, the solution was cooled and concentrated. The light-pink, sweet-smelling solid was dissolved in CH2Cl2 (50 mL) and MeOH (5 mL). The solution was diluted with H2O (150 mL) and then washed with CH2Cl2 (3×75 mL). The combined organic layers were washed with brine (2×100 mL), dried (Na2SO4) and concentrated to yield the title compound (0.57 g, 84%) as an off-white solid: 1H NMR (300 MHz, DMSO-d6) δ 11.39 (s, 1H), 8.03 (d, J=1.2 Hz, 1H), 7.66 (d, 0.9 Hz, 1H), 1.43 (s, 6H).

1. temperatureheated to reflux
2. waitAfter 18 h
3. temperaturethe solution was cooled
4. concentrationconcentrated
5. dissolutionThe light-pink, sweet-smelling solid was dissolved in CH2Cl2 (50 mL)
6. additionThe solution was diluted with H2O (150 mL)
7. washwashed with CH2Cl2 (3×75 mL)
8. washThe combined organic layers were washed with brine (2×100 mL)
9. dry with materialdried (Na2SO4)
10. concentrationconcentrated

ORD record

ord-72af73acb68944edaeb49eeba8271019

Source dataset

uspto-grants-2011_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07879872B2