Methyl iodide → 2,6-Dichloro-4-methylpyridine

Participants

Reaction Conditions

Reaction Steps

A solution of n-BuLi (21.1 mL, 33.8 mmol, 1.6 M) in THF is cooled to −78° C. before a solution of 2,6-dichloropyridine (5.0 g, 33.8 mmol) in THF (36 mL) is added dropwise over a period of 20 min. The reaction mixture is stirred at −78° C. for 30 min, and then iodomethane (4.79 g, 33.8 mmol) is added. The mixture is stirred for 30 min before it is quenched with sat. aq. NH4Cl solution at −78° C. The mixture is extracted with diethyl ether, the org. extract is dried over MgSO4, filtered and concentrated. The crude product is purified by CC on silica gel eluting with heptane:EA 19:1 to give 2,6-dichloro-4-methyl-pyridine (2.34 g) as a colourless oil containing the regio isomer 2,6-dichloro-3-methyl-pyridine; LC-MS: tR=0.89 min, [M+1]+=161.97.

Provenance & Evidence