Methyl iodide → 4-Chloro-2-ethylpyridine

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of diisopropylamine (0.86 ml, 6.1 mmol) in THF (15 ml) at −20° C. was added dropwise a solution of n-butyllithium in hexanes (1.2M, 5.07 ml, 6.1 mmol). The reaction mixture was stirred at −20° C. for 20 minutes and was then cooled to −70° C. A solution of 2-methyl-4-chloropyridine (0.74 g, 5.8 mmol) in THF (10 ml) was added dropwise over 20 minutes and the reaction mixture was stirred for 1 hour at −70° C. Methyl iodide (0.38 ml, 6.1 mmol) was then added dropwise and the reaction was allowed to warm to room temperature with stirring. The solvent was evaporated at reduced pressure and the resulting residue purified by FCC. 1H NMR indicated a ˜2.2:1 mixture of 2-ethyl and 2-(1-methylethyl) compounds. Re-purification by silica FCC [pentane/ether eluting with gradient 9:1 to 1:1] gave the title compound (209 mg, 24%) as colourless oil.

Provenance & Evidence