3-Bromo-4-(2,5-difluoro-4-nitrophenoxy)pyridine synthesis

Yield:1225278-73-8 38%

Reaction Conditions:

in chlorobenzene at 145;

Steps:

A.19

2,5-Difluoro-4-nitro-phenol (1.739 g, 9.93 mmol) and 3-bromo-4-chloro- pyridine (0.637 g, 3.31 mmol) were dissolved in chlorobenzene (6 ml) and heated at 145°C overnight. The solvent was removed under reduced pressure and the residue partitioned between EtOAc and 10% K2CO3 (_aq). The mixture was extracted with EtOAc (2x). The combined organic extracts were washed with 10% K₂CO3 (_aq) and brine, dried, evaporated and purified by silica gel chomatography (hexanes/EtOAc) to yield 3-bromo-4-(2,5-difluoro-4-nitrophenoxy)pyridine (414 mg, 38% yield). ¹H NMR (400 MHz, DMSO-d₆): δ 8.84 (s, 1H), 8.51-8.45 (m, 2H), 7.82-7.78 (m, 1H), 7.22 (d, 1H); MS (ESI) m/z: 331.0 (M+H⁺).

References:

WO2010/51373,2010,A1 Location in patent:Page/Page column 79-80