Reacción #312941

Ecuación de reacción

2,2-dimethyl-N-pyridin-3-ylpropanamide

TMEDA

lithium

iodine

→

title compound

Rendimiento 38.0%

N-(4-Iodopyridin-3-yl)-2,2-dimethylpropanamide

Rendimiento 38.0%

Disolventes

tetrahydrofuran

diethyl ether

tetrahydrofuran

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.STIRRINGstirred for a further 2 hours
2. 2
   TemperaturaThe reaction mixture was again cooled to −78° C.
3. 3
   workup.STIRRINGThe resulting slurry was stirred at −78° C. for 2 hours
4. 4
   TemperaturaThe mixture was warmed to 0° C.
5. 5
   Otrowas quenched with saturated aqueous sodium thiosulfate solution (50 mL)
6. 6
   OtroThe phases were separated
7. 7
   Extracciónthe aqueous phase was extracted with dichloromethane (2×30 mL)
8. 8
   SecadoThe combined organic phase was dried over magnesium sulfate
9. 9
   Concentraciónconcentrated in vacuo
10. 10
    OtroPurification of the residue by column chromatography on silica gel
11. 11
    Lavadoeluting with pentane

Procedimiento

A solution of 2,2-dimethyl-N-pyridin-3-ylpropanamide [(1 g, 5.61 mmol), J. Org. Chem, 48(20), 3401;1998]in tetrahydrofuran (10 mL) and diethyl ether (30 mL) was cooled to −78° C. and TMEDA (2.1 mL, 14 mmol) and nbutyl lithium (1.6M in hexane, 8.8 mL, 14 mmol,) were added dropwise. The mixture was stirred for 15 minutes and was then warmed to −10° C. and stirred for a further 2 hours. The reaction mixture was again cooled to −78° C. and a solution of iodine (3.56 g, 14 mmol) in tetrahydrofuran (10 mL) was added dropwise. The resulting slurry was stirred at −78° C. for 2 hours. The mixture was warmed to 0° C. and was quenched with saturated aqueous sodium thiosulfate solution (50 mL). The phases were separated and the aqueous phase was extracted with dichloromethane (2×30 mL). The combined organic phase was dried over magnesium sulfate and concentrated in vacuo. Purification of the residue by column chromatography on silica gel, eluting with pentane:ethyl acetate, 50:50 afforded the title compound as a yellow solid in 38% yield, 655 mg.

Fuente