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

HRID 977967Notes

Reaction equation

HRID 977967 reaction equation
[S:1]1[CH:5]=[CH:4][S:3][C:2]1=[C:6]([C:12](=[O:21])[NH:13][CH2:14][C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1)[C:7]([O:9]CC)=O.[H-].[Na+].[C:24]([O:33][CH2:34][CH3:35])(=[O:32])/[CH:25]=[CH:26]\[C:27]([O:29][CH2:30][CH3:31])=[O:28].O>CN(C)C=O>[CH2:34]([O:33][C:24]([CH:25]1[CH:26]([C:27]([O:29][CH2:30][CH3:31])=[O:28])[C:7](=[O:9])[C:6](=[C:2]2[S:1][CH:5]=[CH:4][S:3]2)[C:12](=[O:21])[N:13]1[CH2:14][C:15]1[CH:16]=[CH:17][CH:18]=[CH:19][CH:20]=1)=[O:32])[CH3:35]

Participants

6

Reactant 4

HCID 962WaterHCID 24758Sodium hydrideHCID 5271566Diethyl MaleateHCID 20204019ethyl 2-(1,3-dithiol-2-ylidene)-2-(N-benzylcarbamoyl)acetate

Product 1

HCID 139348651-Benzyl-5-(1,3-dithiol-2-ylidene)-4,6-dioxopiperidine-2,3-dicarboxylic acid diethyl ester

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent3×

Procedure

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.

Workup

  1. additionSaid addition
  2. temperaturecooling
  3. stirringThe mixture is stirred at room temperature overnight
  4. extractionextracted with ethyl acetate
  5. washThe extract is washed with a saturated sodium chloride solution
  6. customdried
  7. distillationdistilled
  8. customto remove the solvent
  9. customThe mixture is purified by silica gel column chromatography (solvent, n-hexane:ethyl acetate=1:2)

Sources & evidence

ORD record
ord-35f0fa3623704988a3d6f07dca1323b3
Source dataset
uspto-grants-1987_05
Patent number
US04663319

Reaction notes

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