Potassium Carbonate → 6-bromo-1-(cyclopropylmethyl)-7-phenyl-1H-pyrido[2,3-b][1,4]oxazin-2(3H)-one

Temperature

50 °C

In a 15 mL reaction tube was added 6-bromo-7-phenyl-1H-pyrido[2,3-b][1,4]oxazin-2(3H)-one (300 mg, 0.983 mmol), (bromomethyl)cyclopropane (0.114 mL, 1.180 mmol) and potassium carbonate (408 mg, 2.95 mmol) in anhydrous N,N-dimethylformamide (1 mL) to give a brown suspension. This was stirred at 50° C. under a nitrogen atmosphere for 60 minutes. The reaction mixture was diluted with saturated sodium bicarbonate solution (5 mL) and extracted into ethyl acetate (3×5 mL). The combined organic phases were washed with 50:50 water:brine (3×5 mL), dried over Na2SO4, filtered and concentrated to dryness under reduced pressure to give a brown solid. This was purified by Biotage chromatography (25 g silica cartridge, cyclohexane:ethyl acetate, gradient elution from 90:10 to 20:80) to give the title compound as a beige solid (160 mg, 0.445 mmol, 45.3% yield). 1H NMR (500 MHz, CDCl3): 7.58-7.37 (5H, m), 7.32 (1H, s), 4.88 (2H, s), 3.81 (2H, d), 1.14-1.01 (1H, m), 0.60-0.53 (2H, m), 0.47-0.40 (2H, m).

1. customIn a 15 mL reaction tube
2. customto give a brown suspension
3. extractionextracted into ethyl acetate (3×5 mL)
4. washThe combined organic phases were washed with 50:50 water
5. dry with materialbrine (3×5 mL), dried over Na2SO4
6. filtrationfiltered
7. concentrationconcentrated to dryness under reduced pressure
8. customto give a brown solid
9. customThis was purified by Biotage chromatography (25 g silica cartridge, cyclohexane:ethyl acetate, gradient elution from 90:10 to 20:80)

ORD record

ord-dcd0a39bc75046db853b1c09cee364f0

Source dataset

uspto-grants-2015_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09221838B2