Preparation of riboflavin

US4567261A · kind A · utility

Assignee

• BASF SE

Inventors

• Hansgeorg Ernst · Speyer, DE
• Wolfram Schmidt · Friedelsheim, DE
• Joachim Paust · Schifferstadt, DE

Key dates

• Filing date: Jan 13, 1984
• Grant date: Jan 28, 1986
• Expiry date: Jan 13, 2004

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07D475/02
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Riboflavin of the formula I ##STR1## is prepared by condensing a 4,5-dimethyl-N-(D)-ribityl-2-phenylazoaniline of the formula II ##STR2## where R is H or --Cl, --NO.sub.2 or --CH.sub.3 in the o- or p-position, with barbituric acid of the formula III ##STR3## in the presence of an acid as the condensing agent, by an improved process in which the acidic condensing agent used is an aliphatic or cycloaliphatic/aliphatic tertiary carboxylic acid of the general formula IV ##STR4## where R.sup.1, R.sup.2 and R.sup.3 are each a lower alkyl group, R.sup.1, R.sup.2 and R.sup.3 together containing 3 to 20, preferably 3 to 10, carbon atoms, or R.sup.1 is a lower alkyl group, in particular methyl, and R.sup.2 and R.sup.3 together form a tetramethylene or pentamethylene group. The process can be particularly advantageously carried out using trimethylacetic acid or a commercial mixture of saturated tertiary carboxylic acids, e.g. Versatic .sup.R 10-acid.