Sulfuric Acid → HCID 131711319, compound

HRID 1703514Notes

Reaction equation

HRID 1703514 reaction equation
C(O)(=O)[C@H](CC([O-])=O)[OH:3].[Ca+2].[C:11]([OH:19])(=[O:18])[C@H:12]([CH2:14][C:15]([O-:17])=[O:16])[OH:13].S(=O)(=O)(O)O.[OH-].[K+:26].C(O)(=O)[C@H](CC(O)=O)O>O>[OH2:3].[C:11]([O-:19])(=[O:18])[C@H:12]([CH2:14][C:15]([OH:17])=[O:16])[OH:13].[K+:26]

Participants

6

Reactant 4

HCID 1118Sulfuric AcidHCID 14797Potassium HydroxideHCID 222656L-Malic AcidHCID 131711320HCID 131711320, compound

Product 1

HCID 131711319HCID 131711319, compoundYield 140.5%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
10 °C

Procedure

207.2 g (0.5 mole) of calcium hydrogen L-malate 6 hydrate (C8H10O10.Ca.6H2O) are suspended in 300 ml of water, and 55 ml of 60% (by weight) sulfuric acid are added thereto. The precipitates of calcium sulfate are removed by filtration. The filtrate is passed through a column of about 100 ml of a cation exchange resin [manufactured by Rohm & Haas Co. under the trade name "Amberlite IR-120 (H+ type)] and then a column of about 30 ml of an anion exchange resin [manufactured by Rohm & Haas Co. under the trade name "Amberlite IR-45 (OH- type)] to remove calcium sulfate completely therefrom. 79.2 g (1.4 moles) of potassium hydroxide (purity: 85%) are added gradually to the aqueous L-malic acid solution thus obtained. Insoluble materials are removed by filtration, and the filtrate (pH 4.4) is concentrated under reduced pressure to make the total weight thereof about 300 g. The concentrated filtrate is cooled to 10° C. and the mixture (i.e., the mixture of the concentrated filtrate and crystals precipitated) is stirred at the same temperature for 2 hours. After stirring the mixture had a pH of 5.6. The crystalline precipitates are collected by filtration, washed with an aqueous 80% methanol solution and dried overnight in air at 35° C. 133.6 g of monopotassium L-malate monohydrate are obtained as crystals. Yield: 70.2% The product loses its intramolecular water at 99° to 101° C. and decomposes at 183.5° to 185° C.

Workup

  1. customThe precipitates of calcium sulfate
  2. customare removed by filtration
  3. customunder the trade name "Amberlite IR-45 (OH- type)] to remove calcium sulfate completely
  4. customthus obtained
  5. customInsoluble materials are removed by filtration
  6. concentrationthe filtrate (pH 4.4) is concentrated under reduced pressure
  7. additionthe mixture (i.e., the mixture of the concentrated filtrate and crystals
  8. customprecipitated)
  9. stirringAfter stirring the mixture
  10. customThe crystalline precipitates
  11. filtrationare collected by filtration
  12. washwashed with an aqueous 80% methanol solution
  13. customdried overnight in air at 35° C

Sources & evidence

ORD record
ord-a076f906a13d4177b59646360bb84bfd
Source dataset
uspto-grants-1978_11
Patent number
US04124636

Reaction notes

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