Malic Acid → HCID 131711319, compound

HRID 1703512Notes

Reaction equation

HRID 1703512 reaction equation
C(O)(=O)[C@H](CC(O)=O)[OH:3].[C:10]([OH:18])(=[O:17])[CH:11]([CH2:13][C:14]([OH:16])=[O:15])[OH:12].C([O-])(=O)[C@H](CC([O-])=O)O.[K+:28].[K+]>>[OH2:3].[C:10]([O-:18])(=[O:17])[C@H:11]([CH2:13][C:14]([OH:16])=[O:15])[OH:12].[K+:28]

Participants

4

Reactant 3

HCID 525Malic AcidHCID 222656L-Malic Acid2×HCID 76968137HCID 76968137, compound

Product 1

HCID 131711319HCID 131711319, compound

Procedure

As a result of our investigations, we have now found that when L-malic acid and potassium ion are dissolved in an aqueous solvent at a pH higher than 6.8, a malic acid salt contained in the solution exists substantially in the form of dipotassium L-malate and can not be crystallized out from the aqueous solvent. In this connection, however, we have also found that crystals of monopotassium L-malate monohydrate or crystals composed of L-malic acid and monopotassium L-malate are obtained by cooling an aqueous solution of L-malic acid and potassium ion at a pH of 6.8 or less. Namely, pure crystals of monopotassium L-malate monohydrate are obtained by cooling an aqueous solution of L-malic acid and potassium ion having a pH of 6.8 or less, to initiate crystallization of a potassium salt of L-malic acid, and continuing said crystallization at a pH of 5.3 to 6.8, especially at a pH of 5.3 to 6.5. On the other hand, when the crystallization step described above is continued at a pH lower than 5.3, the crystals obtained as the solid phase are composed of L-malic acid and monopotassium L-malate. Moreover, we have found that pure crystals of monopotassium L-malate monohydrate can also be prepared from impure crystals composed of L-malic acid and monopotassium L-malate by allowing said impure crystals to stand in a small amount of water at a pH of 5.3 to 6.8 until liquid-solid equilibrium is substantially achieved.

Workup

  1. customAs a result of our investigations, we
  2. dissolutionare dissolved in an aqueous solvent at a pH higher than 6.8
  3. customcan not be crystallized out from the aqueous solvent
  4. customare obtained

Sources & evidence

ORD record
ord-b8d4301d279c423891bf1dc5c73ab004
Source dataset
uspto-grants-1978_11
Patent number
US04124636

Reaction notes

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