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:
Nov. 26, 1991
Filed:
Jun. 11, 1990
Applicant:
Inventors:
Ryuichiro Tsumura, Yokohama, JP;
Teruo Muraishi, Yokohama, JP;
Keiichi Ideda, Chigasaki, JP;
Jin-Kai Wang, Yokohama, JP;
Assignee:
Mitsui Toatsu Chemicals, Inc., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07D / ; C07D / ; C07D / ; C07D / ;
U.S. Cl.
CPC ...
548548 ; 548521 ;
Abstract
A process for the preparation of N-substituted maleimides by conducting heat-dehydration and dehydrating imidization of N-substituted maleamic acids under azeotropic distillation of generated water in a solvent mixture containing a solvent capable of forming water azeotrope and an organic aproptic polar solvent, in the presence as catalyst of metallic tin, tin oxide, a tin salt of a maleamic acid or a tin compound which forms a thin salt of the N-substituted maleamic acid in the reaction system.