Reaktion #1065149

Reaktionsgleichung

water

diethyl maleate

sodium hydride

ethyl 2-(1,3-dithiol-2-ylidene)-2-(N-benzylcarbamoyl)acetate

→

1-benzyl-5-(1,3-dithiol-2-ylidene)-4,6-dioxopiperidine-2,3-dicarboxylic acid diethyl ester

Lösungsmittel

dimethylformamide

dimethylformamide

dimethylformamide

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONSaid addition
2. 2
   Temperaturcooling
3. 3
   workup.STIRRINGThe mixture is stirred at room temperature overnight
4. 4
   Extraktionextracted with ethyl acetate
5. 5
   WaschenThe extract is washed with a saturated sodium chloride solution
6. 6
   Sonstigedried
7. 7
   workup.DISTILLATIONdistilled
8. 8
   Sonstigeto remove the solvent
9. 9
   SonstigeThe mixture is purified by silica gel column chromatography (solvent, n-hexane:ethyl acetate=1:2)

Vorschrift

A mixture of ethyl 2-(1,3-dithiol-2-ylidene)-2-(N-benzylcarbamoyl)acetate (1.0 g) and dimethylformamide (25 ml) is added dropwise to a suspension of sodium hydride (63% dispersion in oil, 144 mg) in dimethylformamide (10 ml). Said addition is carried out under ice-cooling. The mixture is stirred at the same temperature for 30 minutes. A solution of diethyl maleate (0.6 ml) in dimethylformamide (10 ml) is added dropwise thereto. The mixture is stirred at room temperature overnight. The mixture is poured into water, and extracted with ethyl acetate. The extract is washed with a saturated sodium chloride solution, dried and then distilled to remove the solvent. The mixture is purified by silica gel column chromatography (solvent, n-hexane:ethyl acetate=1:2) to give 1-benzyl-5-(1,3-dithiol-2-ylidene)-4,6-dioxopiperidine-2,3-dicarboxylic acid diethyl ester (196 mg) as yellow oil.

Quelle