反应详情

A solution of 2-hydroxy-3-(trifluoromethyl)pyridine (10.0 g) and bromine (3.08 ml, 9.60 g) in methanol (50 ml) was stirred at 20° C. for 22 h. The solution was concentrated and the residue partitioned between ethyl acetate (400 ml) and water (100 ml). The layers were separated and the organic layer was washed with 5% Na2S2O3aq. (100 ml) and brine (100 ml), dried over sodium sulphate, filtered and concentrated. Purified by Biotage SNAP cartridge KP-Sil column twice (100 g, heptane:ethyl acetate=1:0, 3:1 to 2:1) to give 13.69 g light yellow solid as 5-bromo-2-hydroxy-3-(trifluoromethyl)pyridine (95%).

1. concentrationThe solution was concentrated
2. customthe residue partitioned between ethyl acetate (400 ml) and water (100 ml)
3. customThe layers were separated
4. washthe organic layer was washed with 5% Na2S2O3aq
5. dry with material(100 ml) and brine (100 ml), dried over sodium sulphate
6. filtrationfiltered
7. concentrationconcentrated
8. customPurified by Biotage SNAP cartridge KP-Sil column twice (100 g, heptane:ethyl acetate=1:0, 3:1 to 2:1)