Reaktion #328952

Reaktionsgleichung

Potassium cyanide

potassium cyanide

3-bromomethyl-2,6-dichloro-pyridine

3,3-dibromomethyl-2,6-dichloro-pyridine

2,6-dichloro-3-methyl-pyridine

3-bromomethyl-2,6-dichloro-pyridine

→

(2,6-dichloro-pyrid-3-yl)-acetonitrile

Lösungsmittel

ethanol

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwas added dropwise at 40° C. over a period of 30 minutes
2. 2
   TemperaturThe reaction mixture was heated
3. 3
   Temperaturto reflux for 3 hours
4. 4
   TemperaturThe reaction mixture was cooled to 40° C.
5. 5
   TemperaturThe reaction mixture was heated
6. 6
   Temperaturto reflux for a further 3 hours
7. 7
   FiltrationThe reaction mixture was filtered
8. 8
   Sonstigeto remove the solids
9. 9
   Waschenthe solids were washed with ethyl acetate
10. 10
    EinengenThe combined filtrates were concentrated
11. 11
    workup.ADDITIONThe residue was diluted with ethyl acetate
12. 12
    WaschenThe organic solution washed with aqueous sodium hydrogen carbonate (saturated) and brine
13. 13
    Trocknendried over magnesium sulfate
14. 14
    Einengenconcentrated
15. 15
    SonstigeThis residue was purified by column chromatography on silica gel (eluent: ethyl acetate/hexane from 3:100 to 1:1)

Vorschrift

Potassium cyanide (1.0 g) was dissolved in water by heating to 40° C. A mixture of 3-bromomethyl-2,6-dichloro-pyridine, 3,3-dibromomethyl-2,6-dichloro-pyridine, and 2,6-dichloro-3-methyl-pyridine (Example 4.1) (3.2 g) suspended in ethanol (20 ml) was added dropwise at 40° C. over a period of 30 minutes. The reaction mixture was heated to reflux for 3 hours. The reaction mixture was cooled to 40° C. and another equivalent of potassium cyanide was added. The reaction mixture was heated to reflux for a further 3 hours and then stored at ambient temperature for 16 hours. The reaction mixture was filtered to remove the solids and the solids were washed with ethyl acetate. The combined filtrates were concentrated. The residue was diluted with ethyl acetate. The organic solution washed with aqueous sodium hydrogen carbonate (saturated) and brine, dried over magnesium sulfate, and concentrated. This residue was purified by column chromatography on silica gel (eluent: ethyl acetate/hexane from 3:100 to 1:1) to give slightly impure (2,6-dichloro-pyrid-3-yl)-acetonitrile (1.5 g) which solidified on standing. This material was used without further purification. 1H-NMR (400 MHz, CDCl3): 3.83 (s, 2H), 7.37 (d, 1H), 7.85 (d, 1H) ppm.

Quelle