The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 07, 1987
Filed:
May. 03, 1985
Applicant:
Inventors:
Assignee:
BASF Aktiengesellschaft, Ludwigshafen, DE;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07D / ; C07C / ;
U.S. Cl.
CPC ...
544251 ; 534858 ;
Abstract
An improved process for the preparation of riboflavin by condensation of a 4,5-dimethyl-N-(D)-ribityl-2-phenylazoaniline derivative with barbituric acid in the presence of an acidic condensing agent in an organic solvent, wherein a 4,5-dimethyl-N-(D)-ribityl-2-(o-alkoxyphenylazo)-aniline of the formula IIa ##STR1## where R is alkyl of 1 to 4 carbon atoms, in particular methyl, is reacted with barbituric acid, as well as the novel intermediates of the formula IIa.