Methyl iodide → 3,5-Dichloro-2-methylpyridine

Participants

Reaction Conditions

Reaction Steps

N,N-Diisopropylamine (65.6 ml) was dissolved in anhydrous THF (150 ml), n-butyl lithium (a 1.54 mol/l solution in hexane, 300 ml) was dropwise added thereto at −78° C. in an argon atmosphere, and the mixture was stirred for 5 minutes. After a solution of 3,5-dichloropyridine (63 g) in anhydrous THF (600 ml) was dropwise added thereto and the mixture was stirred for 1 hour, methyl iodide (29.2 ml) was dropwise added thereto, and the mixture was stirred for 1.5 hours. Water was added thereto, the reaction mixture was extracted with ethyl acetate, the extract was washed with a saturated aqueous sodium chloride solution and dried over magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was purified by silica gel column chromatography (hexane:ethyl acetate=10:1), the resulting residue was suspended in hexane, and the precipitated crystals were collected by filtration to give 3,5-dichloropicoline (62.8 g, 91%) as colorless crystals.

Provenance & Evidence