Réaction #1016

Équation de réaction

3,5-Dichloropyridine

LDA

sodium hydrogen carbonate

iodomethane

→

title compound

Rendement 53.0%

3,5-Dichloro-4-methylpyridine

Rendement 53.0%

Solvants

THF

THF

dichloromethane

Conditions de réaction

Traitement

1. 1
   workup.STIRRINGthe reaction mixture stirred for a further 1.5 h at -70° C
2. 2
   Autrethe organic phase separated
3. 3
   Séchagedried (MgSO4)
4. 4
   Concentrationconcentrated in vacuo

Mode opératoire

3,5-Dichloropyridine (2.04 g, 13.5 mmol) in THF (5 ml) was added dropwise to a solution of LDA [prepared from diisopropylamine (1.9 ml, 13.5 mmol) and n-butyllithium (1.6M, 8.4 ml, 13.5 mmol)] in THF (25 ml) at -70° C. After stirring at this temperature for 5 min, iodomethane (0.85 ml, 13.5 mmol) was added and the reaction mixture stirred for a further 1.5 h at -70° C. Saturated sodium hydrogen carbonate solution (20 ml) and dichloromethane (20 ml) was added and the organic phase separated, dried (MgSO4), and concentrated in vacuo. The residue was subjected to chromatography (SiO2 ; Et2O-hexane, 1:3) to afford the title compound (1.16 g) as a pale yellow solid; δH (CDCl3) 2.46 (3H, s, Me), and 8.36 (2H, s, pyridine H2, H6).

Source