反应详情

温度

-75 °C

To a solution of n-butyllithium (2.5M, 39 ml, 0.096 mol) in 300 ml of ether cooled to -75° C. was added 4-bromopyridine (15.1 g,0.095 mol) in 100 ml of ether at such a rate to maintain the internal temperature below -50° C. The resulting mixture was stirred at -75° C. for 15 min., and N-methyl,N-methoxy-urethane (5.8 g, 0.043 mol) in 25 ml of ether was added over a 20 min period, and the mixtue was warmed to room temperature and then stirred for 2 h. The mixture was quenched with 300 ml of water and the layers were separated. The organic layer was extracted with 6N HCl solution, and the aqueous layer was basified with 10% NaOH solution. The basic solution was extracted with chloroform, organic layer dried over sodium sulfate, concentrated in vacuo, and purified by chromatography on silica (ethyl acetate) to afford 3.9 g (48.7%) of di-(4-pyridyl)ketone.

1. temperatureto maintain the internal temperature below -50° C
2. temperaturethe mixtue was warmed to room temperature
3. stirringstirred for 2 h
4. customThe mixture was quenched with 300 ml of water
5. customthe layers were separated
6. extractionThe organic layer was extracted with 6N HCl solution
7. extractionThe basic solution was extracted with chloroform, organic layer
8. dry with materialdried over sodium sulfate
9. concentrationconcentrated in vacuo
10. custompurified by chromatography on silica (ethyl acetate)