METHOD FOR PREPARING GUANIDINO ACETIC ACID

Abstract

A modified method for preparing guanidino acetic acid (GAA) involves reacting cyanamide with an excess molar amount of glycine in an aqueous reaction mixture, in the presence of a base. The method avoids high molar amounts of base or acid for pH control, and maintains the reaction selectivity and product yields.

Description

Claims

1. A method for preparing guanidino acetic acid (GAA) from cyanamide and glycine, the method comprising: continuously adding the cyanamide and the glycine to a pre-mixed aqueous solution comprising the glycine and a base,wherein a rate of addition of the cyanamide and the glycine is adjusted such that a molar ratio of base to glycine within a reaction mixture is kept constant at 0.1 to 0.4 over an entire reaction period.

2. The method of claim 1, wherein the cyanamide is reacted with an overall equimolar amount of the glycine, and wherein subsequently, a remaining molar amount of the cyanamide without glycine is continuously added to a glycine containing reaction mixture while maintaining a pH of the reaction mixture below 10 by adding an acid.

3. The method of claim 1, wherein the cyanamide and the glycine are simultaneously added to the reaction mixture in a form of a mixture comprising both the cyanamide and the glycine.