Kansas State University Research Foundation

Paul A Sieb

Russell C Hoseney

Charles W Deyoe

A method of preparing nutritionally useful 2-phosphated ester derivatives of ascorbic acid in extremely high yields is disclosed which includes steps of reacting an ascorbic acid such as L-ascorbic acid or a derivative such as 5,6-O-isopropylidene-L-ascorbic acid with a phosphorylating agent in the presence of a tertiary amine while maintaining the pH of the reaction mixture at a level of at least about 8 for achieving almost quantitative 2-phosphorylation of the ascorbic acid derivative. In preferred forms 5,6-O-isopropylidene-L-ascorbic acid is reacted in water with phosphorous oxychloride in the presence of about a fivefold excess of pyridine relative to the acid and at low temperatures (-5 to +5.degree. C.); an alkali metal hydroxide such as potassium hydroxide is added to the reaction mixture as needed for maintaining the pH thereof at a level of about 12-13 during the entire phosphorylation reaction. Production of the diester of the ascorbic acid derivative can be selectively increased by omitting the tertiary amine from the reaction mixture and conducting the reactant at an elevated temperature of from about 30.degree.-60.degree. C.

Growing community of inventors

Manhattan, KS, United States of America

Paul A Sieb