Phosphorus oxybromide → 2-Bromo-5-chloro-3-fluoropyridine

Temperatur

130 °C

To solid 5-chloro-3-fluoro-2-hydroxypyridine (75 g, 0.51 mmol) was added melted POBr3 (150 g, 0.52 mmol). DMF (2 mL) was then added by pipet, and the mixture was heated at 130° C. for 1 h. The excess POBr3 was quenched by the careful addition of water to the reaction mixture at 0° C., and the resulting mixture was dissolved in a 2:1 mixture of EtOAc:water. The organic layer was washed three times with water and once with brine, dried over sodium sulfate, filtered and concentrated in vacuo. The resulting yellow oil was passed through a plug of silica gel (10% Et2O:90% hexanes) to provide the title compound as a white solid (79.4 g, 74%). The product was characterized by 1H NMR.

1. customThe excess POBr3 was quenched by the careful addition of water to the reaction mixture at 0° C.
2. dissolutionthe resulting mixture was dissolved in a 2:1 mixture of EtOAc
3. washThe organic layer was washed three times with water
4. dry with materialonce with brine, dried over sodium sulfate
5. filtrationfiltered
6. concentrationconcentrated in vacuo

ORD-Eintrag

ord-f946339c41b741acb5c89d9841ba480e

Quelldatensatz

uspto-grants-2010_12

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07851484B2