反应详情

A mixture of methyl 6-bromo-3-hydroxypicolinate (26B) (308 mg, 1.33 mmol) and 2-phenoxyethanol (183 mg, 1.33 mmol) were stirred in dry DCM (10 mL). PPh3-polystyrene bound (665 mg, 2.0 mmol) was added, followed by the drop-wise addition of DIAD (0.387 mL, 2.0 mmol). The mixture was stirred for 48 hours, then filtered through Celite and concentrated under reduced pressure. The crude material was purified by flash column chromatography on silica gel eluting with a gradient of PE/EtOAc 9:1-7:3 to provide 334 mg (72%) of the desired compound methyl 6-bromo-3-(2-phenoxyethoxy)picolinate (27A): 1H NMR (300 MHz, CDCl3) δ7.58-6.90 (7H, m), 4.43 (2H, m), 4.34 (2H, m), 3.91 (3H, s).

1. additionwas added
2. filtrationfiltered through Celite
3. concentrationconcentrated under reduced pressure
4. customThe crude material was purified by flash column chromatography on silica gel eluting with a gradient of PE/EtOAc 9:1-7:3