Formaldehyde → N,N-Bis(carboxymethyl)-L-glutamic acid

Participants

Reaction Conditions

Reaction Steps

A reactor was charged with 314.0 g of L-glutamic acid, 350.0 g of a 40% aqueous solution of sodium hydroxide and 200.0 g of water. The temperature of the contents was raised to 90° C., followed by the addition of 110.6 g of prussic acid, 405.4 g of 30% formalin and 450.0 g of a 40% aqueous solution of sodium hydroxide. The resulting mixture was stirred at 105° C. for 2 hours. After the completion of the reaction, the residual prussic acid was decomposed by the addition of 30.0 g of 10% formalin. 1000.0 g of a 40% aqueous solution of sulfuric acid was added to the resulting mixture to conduct crystallization. The crystalline product thus deposited was recovered by filtration to obtain 441.8 g of N,N-bis(carboxymethyl)glutamic acid as a crude crystal. This crude crystal was recrystallized from water/methanol to give 411.9 g of purified N,N-bis(carboxymethyl)glutamic acid (yield: 75.5%). This acid was neutralized with 40% aqueous sodium hydroxide to give a tetrasodium N,N-bis(carboxymethyl)-glutamate.

Provenance & Evidence