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

Temperatur

-10 °C

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.

1. stirringstirred for a further 2 hours
2. temperatureThe reaction mixture was again cooled to −78° C.
3. stirringThe resulting slurry was stirred at −78° C. for 2 hours
4. temperatureThe mixture was warmed to 0° C.
5. customwas quenched with saturated aqueous sodium thiosulfate solution (50 mL)
6. customThe phases were separated
7. extractionthe aqueous phase was extracted with dichloromethane (2×30 mL)
8. dry with materialThe combined organic phase was dried over magnesium sulfate
9. concentrationconcentrated in vacuo
10. customPurification of the residue by column chromatography on silica gel
11. washeluting with pentane

ORD-Eintrag

ord-d0cc5de8244e4cae9cb35f8560bba04e

Quelldatensatz

uspto-grants-2009_07

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07557121B2