反应详情

温度

-78 °C

To a solution of 2,5-dibromopyridine (1.00 g, 4.22 mmol) in 50 mL of toluene at −78° C. was added n-BuLi (2.0 mL, 5.0 mol, 2.5 M in THF) dropwise. After 2 h, ethyl 1-formyl-4-oxo-4H-quinolizine-3-carboxylate (1.35 g, 5.5 mmol) was added. The reaction was stirred at −78° C. for another 1 h, then transferred to a 0° C. ice water bath. After an additional 1 h at 0° C., saturated aqueous ammonium chloride (10 mL) was added. The mixture was warmed to rt and filtered to remove an insoluble brown solid. The filtrate was separated, and the organic layer was dried over sodium sulfate, filtered, and concentrated in vacuo. The resultant residue was subjected to purification via silica gel chromatography from 0-5% MeOH in CH2Cl2 to yield crude ethyl 1-[(5-bromopyridin-2-yl)(hydroxy)methyl]-4-oxo-4H-quinolizine-3-carboxylate that gave a mass ion (ES+) of 402.9 (79Br) for M+H+.

1. customtransferred to a 0° C.
2. waitAfter an additional 1 h at 0° C.
3. temperatureThe mixture was warmed to rt
4. filtrationfiltered
5. customto remove an insoluble brown solid
6. customThe filtrate was separated
7. dry with materialthe organic layer was dried over sodium sulfate
8. filtrationfiltered
9. concentrationconcentrated in vacuo
10. customThe resultant residue was subjected to purification via silica gel chromatography from 0-5% MeOH in CH2Cl2