Diethyl Ether → Di-4-pyridinylmethanone

Temperature

-75 °C

To a solution of n-butyllithium (2.5 M, 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-methoxyurethane (5.8 g, 0.043 mol) in 25 mL of ether was added over a 20 min period, and the mixture 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 6 N HCl solution, and the aqueous layer was basified with 10% NaOH solution. The basic solution was extracted with chloroform, the 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 mixture 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 6 N HCl solution
7. extractionThe basic solution was extracted with chloroform
8. dry with materialthe organic layer dried over sodium sulfate
9. concentrationconcentrated in vacuo
10. custompurified by chromatography on silica (ethyl acetate)

ORD record

ord-a8c1569148074e6a8bf5eb66d1c21f2d

Source dataset

uspto-grants-1997_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05631264