Derivatives of 2-pyrrolidone-5-carboxylic acid and method of obtaining them

摘要

The new, crystalline trihydrates of sodium L- and D-2-pyrrolidone-5-carboxylate. These trihydrates can be obtained by adjusting the concentration and the temperature in an aqueous solution of sodium L- or D-2-pyrrolidone-5-carboxlate in such a manner that the solubility of the desired trihydrate is exceeded.