Oxalic Acid → Malic Acid

HRID 1357338Notes

Reaction equation

HRID 1357338 reaction equation
C1(=O)[O:6][C:4](=[O:5])[CH:3]=C1.[OH-].[Na+].[O-2].[La+3].[O-2].[O-2].[La+3].[C:15]([OH:22])(=[O:21])/[CH:16]=[CH:17]\[C:18]([OH:20])=[O:19].N(CCO)CCO.[C:30]([OH:35])(=[O:34])[C:31](O)=[O:32]>O>[C:15]([OH:22])(=[O:21])/[CH:16]=[CH:17]\[C:18]([OH:20])=[O:19].[C:30]([OH:35])(=[O:34])[CH:31]([CH2:3][C:4]([OH:6])=[O:5])[OH:32].[C:15]([OH:22])(=[O:21])/[CH:16]=[CH:17]/[C:18]([OH:20])=[O:19]

Participants

10

Reactant 6

HCID 971Oxalic AcidHCID 7923Maleic AnhydrideHCID 8113DiethanolamineHCID 14798Sodium HydroxideHCID 150906Lanthanum sesquioxideHCID 444266Maleic Acid

Product 3

HCID 525Malic AcidHCID 444266Maleic AcidHCID 444972Fumaric Acid

Reagents, catalysts & solvents 1

HCID 962WaterSolvent2×

Conditions

Temperature
80 °C

Procedure

A maleic acid solution was prepared by dissolving 56.0 g (0.571 mol) of maleic anhydride in 124.3 ml of water. 116.2 g of this solution was added to 71.3 g of a 48% lye solution (0.856 mol NaOH). During the addition the temperature of the reaction mixture was maintained at 70-90° C. Lanthanum(III)oxide, La2O3,(15.5 g, 0,048 mol) was dissolved in remaining maleic acid solution ( 64.1 g, 0.192 mol) and added to the reaction mixture together with diethanolamine (20.0 g, 0.190 mol). The reaction mixture was stirred at 95° C. under a reflux condenser for 24 hours. The reaction mixture was rendered acidic (pH 3.5) by addition of oxalic acid, C2O4H2.2H2O (47.96 g in 71.90 ml of water, 0.380 mol) and stirred at 80° C. for 1 hour. The reaction mixture was cooled and the formed La(III) oxalate precipitate was removed by filtration. From the remaining solution (194.1 g), which contained water 75.2%, the organic compounds were analyzed by means of 13C NMR spectra. BCEEAA and BCEEA were identified from the 13C NMR spectra. Unreacted initial substances were identified on the basis of reference spectra: diethanolamine and maleic acid, as well as oxalic acid used for the precipitation of the catalyst. Malic acid and fumaric acid were formed as byproducts of the reaction; these were also identified on the basis of reference spectra.

Workup

  1. additionDuring the addition the temperature of the reaction mixture
  2. stirringstirred at 80° C. for 1 hour
  3. temperatureThe reaction mixture was cooled
  4. customthe formed La(III) oxalate precipitate was removed by filtration
  5. customdiethanolamine and maleic acid, as well as oxalic acid used for the precipitation of the catalyst

Sources & evidence

ORD record
ord-e1d38d18d4b445d88de30246aca07352
Source dataset
uspto-grants-2003_07
Patent number
US06590120B1

Reaction notes

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