反应详情

To a diethyl ether (500 mL) solution of 2,5-dibromopyridine (25 g, 110 mmol) was added dropwise n-butyl lithium (2.67 M n-hexane solution, 45 mL, 120 mmol) at −76° C., which was stirred for 25 minutes. To this solution was added dropwise N,N-dimethylformamide (9.0 mL, 120 mmol) at −76° C. Upon completion of this addition, the reaction solution was gradually cooled to room temperature. This mixture was partitioned into ethyl acetate and water. The organic layer was separated and concentrated under a reduced pressure. The residue was purified by silica gel column chromatography (heptane:ethyl acetate=8:1) to obtain the title compound (8.0 g, 41%).

1. additionUpon completion of this addition
2. customThis mixture was partitioned into ethyl acetate and water
3. customThe organic layer was separated
4. concentrationconcentrated under a reduced pressure
5. customThe residue was purified by silica gel column chromatography (heptane:ethyl acetate=8:1)