Methyl iodide → 3,5-Dichloro-4-methylpyridine

Participants

Reaction Conditions

Reaction Steps

A solution of diisopropylamine (10.5 mL) in dry tetrahydrofuran (150 mL) is cooled to -75° C. and treated with a solution of butyl lithium in hexane (30 mL; 2.5 M) during 10 minutes. After stirring for 1 hour at -75° C. the mixture is treated with a solution of 3,5-dichloropyridine (10.8 g) in dry tetrahydrofuran (55 mL) and stirred for a further 30 minutes. It is then treated with methyl iodide (4.7 mL) in dry tetrahydrofuran (10 mL) during 10 minutes, and the solution is allowed to rise gradually to room temperature. After stirring for 2 hours, the mixture is treated with saturated aqueous sodium bicarbonate solution (50 mL), followed by diethyl ether (100 mL). The organic layer is washed with brine, dried and evaporated, and the resulting residue is subjected to flash chromatography, to give 3,5-dichloro-4-methylpyridine (10.6 g), m.p. 46°-47° C.

Provenance & Evidence