Formaldehyde → Ethylenediaminetetraacetic Acid

HRID 1472946Notes

Reaction equation

HRID 1472946 reaction equation
C(N)CN.[OH-].[Na+].[C-]#N.[Na+].C=O.O.[CH2:13]([N:24]([CH2:29][C:30]([O-:32])=[O:31])[CH2:25][C:26]([O-:28])=[O:27])[CH2:14][N:15]([CH2:20][C:21]([O-:23])=[O:22])[CH2:16][C:17]([O-:19])=[O:18].[Na+].[Na+].[Na+].[Na+].N(CC([O-])=O)(CC([O-])=O)CC([O-])=O.[Na+].[Na+].[Na+]>>[CH2:14]([N:15]([CH2:20][C:21]([OH:23])=[O:22])[CH2:16][C:17]([OH:19])=[O:18])[CH2:13][N:24]([CH2:29][C:30]([OH:32])=[O:31])[CH2:25][C:26]([OH:28])=[O:27]

Participants

8

Reactant 7

HCID 712FormaldehydeHCID 962WaterHCID 3301EthylenediamineHCID 6144Edetate SodiumHCID 8929Sodium CyanideHCID 14798Sodium HydroxideHCID 21152Glycine, N,N-bis(carboxymethyl)-, trisodium salt

Product 1

HCID 6049Ethylenediaminetetraacetic Acid

Conditions

Temperature
70 °C

Procedure

1-mol of ethylenediamine (60.0-g) is mixed with 0.18-mol sodium hydroxide (14.7-g of 50% NaOH) and raised to 70° C. 4.47-mol of sodium cyanide (729.6-g of 30% aq sln) and 4.55-mol of formaldehyde (273.2-g of 50% aq sln) are added at a constant rate over 4.5-hrs and the reaction is allowed to quickly reach boiling temperature (materials can be obtained at Sigma-Aldrich). Any vapors escaping from the reaction are refluxed back to the reactor for the first half of the addition. After the first half of the addition, vapors are no longer refluxed, but distilled away from the reactor. Upon completion of the addition, the reaction is boiled for 2-hrs to remove any excess ammonia. 222.2-mol of water (151.3-g) are added back to the reaction and the reaction is cooled to room temperature. The resulting product contains 39.90-wt % tetrasodium ethylenediaminetetraacetate (Na4EDTA) and 2.5-wt % trisodium nitrilotriacetate (Na3NTA), as determined by HPLC analysis (see method below).

Workup

  1. customtemperature (materials can be obtained at Sigma-Aldrich)
  2. temperatureare refluxed back to the reactor for the first half of the addition
  3. additionAfter the first half of the addition, vapors
  4. temperatureare no longer refluxed
  5. distillationdistilled away from the reactor
  6. additionUpon completion of the addition
  7. waitthe reaction is boiled for 2-hrs
  8. customto remove any excess ammonia
  9. temperaturethe reaction is cooled to room temperature

Sources & evidence

ORD record
ord-4d13a1b020c54a36aaf61cdc5cd6095e
Source dataset
uspto-grants-2015_04
Patent number
US09012684B2

Reaction notes

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