process for the production of pyridoxal 5 '- phosphorsaeureester from pyridoxamin - 5' - phosphorsaeureester

摘要

Pyridoxal phosphate is made by treating an aqueous solution of the alkali-metal salts of pyridoxamine phosphate and pyruvic acid, or a substituted pyruvic acid wherein the substituent may be an electrophilic radical or an alkyl, aryl or aralkyl group which may be substituted by an electrophilic radical, with a cupric, iron, nickel or cobalt salt which is soluble in water or in the reaction mixture, passing the reaction mixture through a cation exchange resin and eluting the pyridoxal phosphate therefrom with water. The reaction is preferably carried out in an inert atmosphere in the absence of light using proportions of from 1 to 2 mols. of pyruvic acid or substituted pyruvic acid to 1 mol. of pyridoxamine phosphate and 1/n mols. of the cupric, iron, nickel or cobalt salt (n being the number of atoms of the metal per mol. of the metal salt chosen). Suitable electrophilic substituents which may be present on the pyruvic acid or alkyl, aryl or aralkyl pyruvic acid are for example carboxyl or acetyl groups. The completion of the reaction and the elution of the desired fraction from the cation exchange resin may be followed by measurement of the ultra-violet absorption spectrum. In examples pyridoxamine phosphate is converted to pyridonal phosphate in aqueous alkali according to the invention by treatment with (1) pyruvic acid and cupric sulphate; (2) a -keto-glutaric acid and copper acetate; (3) a -keto-butyric acid and copper acetate; (4), (5) and (6) sodium pyruvate and copper acetate; (7) sodium pyruvate and ferric ammonium sulphate; (8) sodium pyruvate and cobalt nitrate; and (9) sodium pyruvate and nickel nitrate.