Reaktion #82468

Reaktionsgleichung

Diethyl oxalacetate

piperidine

3-aminopyrazine-2-carboxaldehyde

→

compound

Ausbeute 28.0%

Pyrido[2,3-b]pyrazine-6,7-dicarboxylic acid, diethyl ester

Ausbeute 28.0%

Lösungsmittel

toluene

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturAfter the reaction mixture is refluxed for two hours
2. 2
   Sonstigethe toluene is removed under reduced pressure
3. 3
   Sonstigeto give a dark red oily residue
4. 4
   SonstigeThe product is purified by column chromatography on silica gel (hexane:EtOAc, 4:1)
5. 5
   Sonstigeaffording 3.1 g (58% yield)
6. 6
   SonstigeCrystallization from ether-hexane (4:1)

Vorschrift

Diethyl oxalacetate, (4.7 g, 0.25 mol) and piperidine (1.66 g, 1.93 mL) are added to 3-aminopyrazine-2-carboxaldehyde (2.4 g, 0.0195 mol) dissolved in 250 mL of toluene. After the reaction mixture is refluxed for two hours, the toluene is removed under reduced pressure to give a dark red oily residue. The product is purified by column chromatography on silica gel (hexane:EtOAc, 4:1), affording 3.1 g (58% yield), of the crude desired product. Crystallization from ether-hexane (4:1) gives analytically pure compound 1.5 g (28%) having a melting point 83°-85° C.

Quelle