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:
Jul. 09, 1985
Filed:
Jan. 18, 1983
Applicant:
Inventors:
Helmut aus der Funten, Niederkassel-Mondorf, DE;
Wilhelm Vogt, Cologne, DE;
Assignee:
Dynamit Nobel AG, Troisdorf, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
549307 ;
Abstract
The present invention relates to the hydrogenation of phthalic acid anhydride to phthalide. A nickel catalyst of low nickel content is used as hydrogenation catalyst, and a benzoic acid alkyl ester as solvent. Small amounts of an alkanol can be added to the benzoic acid ester. On the basis of these specific conditions, the formation of by-products such as toluylic or phthalic acids in the hydrogenation is greatly diminished, and phthalide yields are obtained which, if the preferred conditions are maintained, can amount to as much as 90%.