Iodoethane → 4-Ethyl-3-fluoropyridine

Temperature

-78 °C

nButyllithium (1.6M in tetrahydrofuran, 62.4 ml, 100 mmol) was added dropwise to a solution of diisopropylamine (10 g, 100 mmol) in tetrahydrofuran (110 mL), cooled to −78° C. 3-Fluoropyridine (10 g, 100 mmol) was added dropwise and the reaction mixture was stirred for 1 hour with the temperature maintained below −60° C. Ethyl iodide (31.2 g, 200 mmol) was then added dropwise and the mixture was allowed to stir at room temperature for 30 minutes. The reaction mixture was slowly diluted with water, the solvent was evaporated under reduced pressure and the residue was partitioned between ethyl acetate and water. The organic layer was separated, dried over magnesium sulfate and concentrated in vacuo to give a crude residue. The residue was distilled and title product was obtained during a temperature range of 152-156° C., in 35% yield, 4.46 g.

1. temperaturemaintained below −60° C
2. stirringto stir at room temperature for 30 minutes
3. customthe solvent was evaporated under reduced pressure
4. customthe residue was partitioned between ethyl acetate and water
5. customThe organic layer was separated
6. dry with materialdried over magnesium sulfate
7. concentrationconcentrated in vacuo
8. customto give a crude residue
9. distillationThe residue was distilled

ORD record

ord-f33f998aa7554ac8ab263c1d7f1abb1f

Source dataset

uspto-grants-2009_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07557121B2