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:
Feb. 21, 1989
Filed:
Nov. 19, 1986
Applicant:
Inventor:
Johannes Grimmer, Ludwigshafen, DE;
Assignee:
BASF Aktiengesellschaft, Ludwigshafen, DE;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
544251 ;
Abstract
Riboflavin of the formula I ##STR1## is prepared by an improved process by condensing a 4,5-dimethyl-N-(D)-ribityl-2-phenylazoaniline of the formula II ##STR2## where R is H, --CL, --NO.sub.2, --CH.sub.3 or --OCH.sub.3 in the o- or p-position, with barbituric acid of the formula III ##STR3## in the presence of an acid as a condensing agent, by a process in which the acidic condensing agent used is an aliphatic secondary carboxylic acid of the general formula IV ##STR4## where R.sup.1 is methyl or ethyl and R.sup.2 is alkyl of 3 or 4 carbon atoms.