Preparation of pure potassium ribonate and ribonolactone

US4294766A · kind A · utility

Assignee

• BASF SE

Inventors

• Wolfram Schmidt · Friedelsheim, DE
• Joachim Paust · Schifferstadt, DE

Key dates

• Filing date: Dec 6, 1979
• Grant date: Oct 13, 1981
• Expiry date: Dec 6, 1999

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C51/41
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

An improved process for the preparation of potassium ribonate and of ribonolactone, which is an interesting intermediate for the preparation of riboflavin (vitamin B.sub.2), starting from potassium arabonate. An aqueous potassium arabonate solution is epimerized by adding a water-soluble non-ionic organic solvent, after which the greater part of the non-epimerized potassium arabonate can be separated off in a crystalline form. The mother liquor, which essentially contains potassium ribonate in addition to a small amount of unconverted potassium arabonate, is greatly concentrated and cooled, whereupon pure potassium ribonate crystallizes out; the latter can be lactonized in the conventional manner. Alternatively, the mixture of potassium arabonate and potassium ribonate, contained in the concentrated mother liquor, can be lactonized and the resulting lactone mixture, containing at least 70% by weight of ribonolactone, can be separated by fractional crystallization using dioxane or ethylene glycol monomethyl ether.