Reaktion #1016

Reaktionsgleichung

3,5-Dichloropyridine

LDA

sodium hydrogen carbonate

iodomethane

→

title compound

Ausbeute 53.0%

3,5-Dichloro-4-methylpyridine

Ausbeute 53.0%

Lösungsmittel

THF

THF

dichloromethane

Reaktionsbedingungen

Aufarbeitung

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

Vorschrift

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).

Quelle