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:
Sep. 30, 1997
Filed:
Sep. 13, 1995
Applicant:
Inventors:
Josef Kasbauer, Wermelskirchen, DE;
Helmut Fiege, Leverkusen, DE;
Assignee:
Bayer Aktiengesellschaft, Leverkusen, DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07D / ; C07D / ;
U.S. Cl.
CPC ...
549240 ; 549247 ;
Abstract
Isobenzofurandiones are obtained in particularly advantageous manner by the dehydrogenation of tetrahydroisobenzofurandiones in the presence of catalysts at elevated temperature by a process in which distilled tetrahydro-isobenzofurandiones are heated to temperatures of between 120.degree. and 300.degree. C. in the presence of supported palladium and/or platinum catalysts and in the presence of maleic acid derivatives in a trickle-phase or liquid-phase procedure, the temperature in the liquid-phase procedure being increased at a rate of 0.6.degree. to 3.degree. C. per minute above 80.degree. to 110.degree. C.