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

Temperature

-78 °C

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.

1. stirringthe mixture was stirred for 1 hour
2. stirringthe mixture was stirred for 1.5 hours
3. extractionthe reaction mixture was extracted with ethyl acetate
4. washthe extract was washed with a saturated aqueous sodium chloride solution
5. dry with materialdried over magnesium sulfate
6. distillationthe solvent was distilled off under reduced pressure
7. customThe residue was purified by silica gel column chromatography (hexane:ethyl acetate=10:1)
8. filtrationthe precipitated crystals were collected by filtration

ORD record

ord-eb47d712d29f4d5aa49e5615b4d28c34

Source dataset

uspto-grants-2002_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06395738B1