反应详情

温度

-70 °C

To a suspension of 2,5-dibromopyridine (50.0 g) in diethyl ether (1 L) was added under nitrogen atmosphere a 1.6M n-butyllithium hexane solution (140 mL) at −70° C. over 20 min. The reaction mixture was stirred at −70° C. for 30 min, methyl methoxyacetate (44.0 g) was added at −70 to −45° C. over 15 min. The reaction mixture was warmed to room temperature, 2M hydrochloric acid (110 mL) was added, and the diethyl ether layer was separated. The aqueous layer was extracted with ethyl acetate, the ethyl acetate layer was combined with the diethyl ether layer, and the layers were washed with saturated brine, dried (MgSO4) and concentrated. Cold ether was added to the obtained residue, and the resulting crystals were collected by filtration, washed with cold ether and dried to give the title compound (15.85 g, yield 33%) as colorless crystals. melting point 110-112° C.

1. temperatureThe reaction mixture was warmed to room temperature
2. customthe diethyl ether layer was separated
3. extractionThe aqueous layer was extracted with ethyl acetate
4. washthe layers were washed with saturated brine
5. dry with materialdried (MgSO4)
6. concentrationconcentrated
7. additionCold ether was added to the obtained residue
8. filtrationthe resulting crystals were collected by filtration
9. washwashed with cold ether
10. customdried