Isopropanol → 4-bis(2-hydroxyethyl)amino-L-phenylalanine

Participants

Reaction Steps

About 76 g of 4-amino-L-phenylalanine obtained in Example-1 was dissolved in about 1500 mL water. Into this solution about 84 g of Ethylene oxide gas was purged over a period of about 4 hours at a temperature in the range of from about 20° C. to about 50° C. Periodically, the reaction mixture was tested by HPLC to monitor the degree of completion of the reaction as determined by the content of the in situ intermediate 4-(2-hydroxyethyl)amino)-L-phenylalanine until a level of less than about 1% 4-amino-L-phenylalanine is reached. The crude 4-(bis-(2-hydroxyethyl)amino)-L-phenylalanine was isolated by precipitation by the addition of isopropanol to the concentrated residue of the reaction mixture. The precipitated crude 4-(bis-(2-hydroxyethyl)amino)-L-phenylalanine was filtered, washed with a water-isopropanol mixture, and then dried. The purity of the crude 4-(bis-(2-hydroxyethyl)amino)-L-phenylalanine recovered was found to be about 85 to 92% by HPLC (weight, 83 g) which contains about 5 to 20% of 3-(4-(bis-(2-hydroxyethyl)amino)phenyl)-2-(2-hydroxyethylamino)-propanoic acid, and less than about 3% of 4-(2-hydroxyethyl)amino-L-phenylalanine as determined by HPLC analysis.

Provenance & Evidence