Reaktion #1065139

Reaktionsgleichung

water

sodium hydroxide

Ethyl 1-benzyl-5-(1,3-dithiol-2-ylidene)-3-methyl-4,6-dioxopiperidine-3-carboxylate

HCl

→

1-benzyl-3-(1,3-dithiol-2-ylidene)-5-methyl-2,4-dioxopiperidine

Ausbeute 69.1%

Lösungsmittel

ethanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   ExtraktionThe aqueous solution is extracted with ethyl acetate
2. 2
   WaschenThe extract is washed with a saturated sodium chloride solution
3. 3
   Sonstigedried
4. 4
   workup.DISTILLATIONdistilled
5. 5
   Sonstigeto remove the solvent
6. 6
   workup.DISSOLUTIONThe residue is dissolved in ethanol (20 ml)
7. 7
   Temperaturthe solution is refluxed for one hour
8. 8
   workup.DISTILLATIONThe mixture is distilled
9. 9
   Sonstigeto remove the solvent
10. 10
    SonstigeThe residue is purified by silica gel column chromatography (solvent, ethyl acetate:n-hexane=1:1)
11. 11
    Sonstigeis recrystallized from a mixture of ethyl acetate and n-hexane

Vorschrift

Ethyl 1-benzyl-5-(1,3-dithiol-2-ylidene)-3-methyl-4,6-dioxopiperidine-3-carboxylate (245 mg) is dissolved in ethanol (5 ml), and thereto is added a 10% sodium hydroxide solution (2.5 ml). The mixture is stirred at room temperature overnight. The mixture is acidified with 10% HCl, and poured into water. The aqueous solution is extracted with ethyl acetate. The extract is washed with a saturated sodium chloride solution, dried and then distilled to remove the solvent. The residue is dissolved in ethanol (20 ml) and the solution is refluxed for one hour. The mixture is distilled to remove the solvent. The residue is purified by silica gel column chromatography (solvent, ethyl acetate:n-hexane=1:1), and is recrystallized from a mixture of ethyl acetate and n-hexane to give 1-benzyl-3-(1,3-dithiol-2-ylidene)-5-methyl-2,4-dioxopiperidine (138 mg, 69.1%) as pale yellow needles, m.p. 168°-170° C.

Quelle