Formaldehyde → Ethylenediaminetetraacetic Acid

HRID 1472947Notes

Reaction equation

HRID 1472947 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+]>>[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

7

Reactant 6

HCID 712Formaldehyde2×HCID 962WaterHCID 3301EthylenediamineHCID 6144Edetate SodiumHCID 8929Sodium Cyanide2×HCID 14798Sodium Hydroxide

Product 1

HCID 6049Ethylenediaminetetraacetic Acid

Conditions

Temperature
70 °C

Procedure

1-mol of ethylenediamine (60.0-g) is mixed with 0.16-mol sodium hydroxide (12.8-g of 50% NaOH) and raised to 70° C. 1.95-mol of sodium cyanide (318.4-g of 30% aq sln) and 1.99-mol of formaldehyde (119.2-g of 50% aq sln) are added at a constant rate over 2-hrs, quickly allowing the mixture to heat to boiling temperatures. At the start of the addition and throughout the reaction, steam is used to distill off the ammonia. Another 1.95-mol of sodium cyanide (318.4-g of 30% aq sln) and 1.99-mol of formaldehyde (119.2-g of 50% aq sln) are added at a constant rate over 4-hrs to complete the reaction. 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 39.24-wt % Na4EDTA and 0.4-wt % Na3NTA, as determined by HPLC analysis.

Workup

  1. temperatureto heat
  2. additionAt the start of the addition
  3. customthroughout the reaction, steam
  4. distillationto distill off the ammonia
  5. customthe reaction
  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-357f005d92ce46029408d2350e0b1ad2
Source dataset
uspto-grants-2015_04
Patent number
US09012684B2

Reaction notes

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