Phosphorus oxybromide → 4,7-Dibromofuro[3,2-c]pyridine

Temperature

70 °C

A mixture of 7-bromo-5H-furo[3,2-c]pyridin-4-one (21.2 g, 99 mmol) and POBr3 (31.2 g, 109 mmol) was heated at 70° C. for 5 min, then heated to 120° C. for 2 h. After cooled to rt, the solid was crashed and quenched with aqueous Na2CO3 (200 mL), then diluted with EtOAc (300 mL). The insoluble material was filtered off through a pad of Celite. The organic phase was collected and dried over Na2SO4. The crude material was purified by silica gel chromatography eluting with Hexanes-EtOAc (90:10→85:15) to give the title compound as a white solid (20.75 g, 68%). 1H NMR (CDCl3, 400 MHz): δ=6.91 (d, J=2.3 Hz, 1H), 7.79 (d, J=2.3 Hz, 1H), 8.37 (s, 1H).

1. temperatureheated to 120° C. for 2 h
2. temperatureAfter cooled to rt
3. customquenched with aqueous Na2CO3 (200 mL)
4. additiondiluted with EtOAc (300 mL)
5. filtrationThe insoluble material was filtered off through a pad of Celite
6. customThe organic phase was collected
7. dry with materialdried over Na2SO4
8. customThe crude material was purified by silica gel chromatography
9. washeluting with Hexanes-EtOAc (90:10→85:15)

ORD record

ord-cc0b1653c1a24c6bb6f30b4490aa29cb

Source dataset

uspto-grants-2011_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08022206B2