Reaktion #48011

Reaktionsgleichung

2,3-bis(chloromethyl)pyridine hydrochloride

Sodium

diethyl malonate

→

5,7-dihydro-[1]pyrindine-6,6-dicarboxylic acid diethyl ester

Lösungsmittel

ethanol

ethanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe reaction is heated
2. 2
   Temperaturto reflux for 5 hours
3. 3
   Filtrationfiltered
4. 4
   SonstigeThe filtrate is evaporated
5. 5
   Extraktionextracted with ethyl acetate
6. 6
   WaschenThe combined organic phases are washed with brine
7. 7
   Trocknendried (MgSO4)
8. 8
   Sonstigeevaporated
9. 9
   SonstigeThe crude product is purified by flash column chromatography (3:1-2:1 isohexanes-EtOAc gradient)

Vorschrift

Sodium metal (0.345 g, 15.0 mmol) is dissolved in ethanol (20 ml) and diethyl malonate (0.713 g, 4.70 mmol) is added, followed by a suspension of 2,3-bis(chloromethyl)pyridine hydrochloride (Org. Process Res. Dev., 2002, 6, 938; 1.0 g, 4.70 mmol) in ethanol (15 ml) over 5 minutes. The reaction is heated to reflux for 5 hours, cooled to ambient temperature and filtered. The filtrate is evaporated, taken into water and extracted with ethyl acetate. The combined organic phases are washed with brine, dried (MgSO4) and evaporated. The crude product is purified by flash column chromatography (3:1-2:1 isohexanes-EtOAc gradient) to afford 5,7-dihydro-[1]pyrindine-6,6-dicarboxylic acid diethyl ester, MH+264.

Quelle