Ethanol → 6-Bromo-5-fluoro-2(3H)-benzoxazolone

Temperature

70 °C

To a 100 mL of round bottom flask was added 5-bromo-4-fluoro-2-nitrophenol (0.98 g, 4.15 mmol), tin(II) chloride dihydrate (4.73 g, 20.76 mmol) and 5 mL of EtOH. The reaction mixture was heated to 70° C. for 30 minutes. The reaction mixture was concentrated and washed with saturated NaHCO3 solution, and extracted with DCM (100 mL×3), and concentrated providing the crude product. 1,1′-Carbonyldiimidazole (808 mg, 4983 mmol) was added to the crude product in 20 mL of THF. The reaction mixture was heated at reflux overnight. The reaction mixture was concentrated and purified with silica gel column chromatography, eluting with 0-30% EtOAc/hexane to give 6-bromo-5-fluorobenzo[d]oxazol-2(3H)-one (690 mg, 71.6% yield). MS m/z: 232 (M+1).

1. concentrationThe reaction mixture was concentrated
2. washwashed with saturated NaHCO3 solution
3. extractionextracted with DCM (100 mL×3)
4. concentrationconcentrated
5. customproviding the crude product
6. temperatureThe reaction mixture was heated
7. temperatureat reflux overnight
8. concentrationThe reaction mixture was concentrated
9. custompurified with silica gel column chromatography
10. washeluting with 0-30% EtOAc/hexane

ORD record

ord-2e2d2897ff3c4e6785292e901e75a88f

Source dataset

uspto-grants-2011_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08084479B2