反应详情

A solution of methyl 3-(benzyloxy)-6-bromopicolinate (2.0 g, 6.20 mmol) and LiOH.H2O (0.71 g, 18.60 mmol) in 1,4-dioxane/H2O (100 mL/20 mL) was stirred at 40° C. overnight. The mixture was filtered and the filtrate was acidified to pH=3 by aqueous HCl (2 M) and extracted with EtOAc. The combined organic phase was washed with brine, dried over Na2SO4 and concentrated to afford the product of 3-(benzyloxy)-6-bromopicolinic acid (1.87 g, yield: 97.9%) without further purification. 1H-NMR (CDCl3, 400 MHz) δ 7.52˜7.54 (m, 1H), 7.39˜7.41 (m, 2H), 7.24˜7.34 (m, 4H), 5.24 (s, 2H). MS (M+H)+: 308/310.

1. filtrationThe mixture was filtered
2. extractionextracted with EtOAc
3. washThe combined organic phase was washed with brine
4. dry with materialdried over Na2SO4
5. concentrationconcentrated