Citric Acid → Diethyl 2-(4-tolyl)maleate

HRID 2269806Notes

Reaction equation

HRID 2269806 reaction equation
[CH2:1]([O:3][C:4]([CH2:6]P(=O)(OCC)OCC)=[O:5])[CH3:2].[H-].[Na+].[C:17]1([CH3:30])[CH:22]=[CH:21][C:20]([C:23](=O)[C:24]([O:26][CH2:27][CH3:28])=[O:25])=[CH:19][CH:18]=1.C(O)(=O)CC(CC(O)=O)(C(O)=O)O>O1CCCC1>[C:17]1([CH3:30])[CH:18]=[CH:19][C:20](/[C:23](=[CH:6]/[C:4]([O:3][CH2:1][CH3:2])=[O:5])/[C:24]([O:26][CH2:27][CH3:28])=[O:25])=[CH:21][CH:22]=1

Participants

6

Reactant 4

HCID 311Citric AcidHCID 13345Triethyl phosphonoacetateHCID 24758Sodium hydrideHCID 2736443Ethyl 2-(4-methylphenyl)-2-oxoacetate

Product 1

HCID 18348039Diethyl 2-(4-tolyl)maleateYield 92.5%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent3×

Procedure

A solution of diethyl ethoxycarbonylmethylphosphonate (3.3 g) in anhydrous tetrahydrofuran (20 ml) is added dropwise to a suspension of sodium hydride (60%, oily) (676 mg) in anhydrous tetrahydrofuran (30 ml) under a nitrogen atmosphere and ice cooling, and further a solution of ethyl 4-tolylglyoxylate (2.96 g) in anhydrous tetrahydrofuran (22 ml) is added dropwise thereto. The mixture is stirred at room temperature for 30 minutes, a 10% aqueous citric acid solution is added to the reaction mixture, and the whole is extracted with ether. The organic layer is washed with water and saturated brine successively, dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The resulting residue is purified by silica gel column chromatography to give 3.57 g (88%) of diethyl 2-(4-tolyl)maleate.

Workup

  1. extractionthe whole is extracted with ether
  2. washThe organic layer is washed with water and saturated brine successively
  3. dry with materialdried over anhydrous magnesium sulfate
  4. concentrationconcentrated under reduced pressure
  5. customThe resulting residue is purified by silica gel column chromatography

Sources & evidence

ORD record
ord-a34f7d74637d464c9090e1aba6a66d1b
Source dataset
uspto-grants-2001_12
Patent number
US06329547B1

Reaction notes

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