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:
Jun. 30, 1998
Filed:
Feb. 06, 1996
Torsten Groth, Koln, DE;
Karl-Erwin Piejko, Bergisch Gladbach, DE;
Winfried Joentgen, Koln, DE;
Josef Kasbauer, Wermelskirchen, DE;
Bernd Alig, Konigswinter, DE;
Werner Struver, Leverkusen, DE;
Bayer Aktiengesellschaft, Leverkusen, DE;
Abstract
N-Substituted cyclic imides are obtained by reacting a cyclic acid anhydride with an amine in the presence of a solvent and an acid catalyst at 80.degree. to 200.degree. C. and with removal of the water formed, it being particularly advantageous to carry out this reaction in the presence of a stabilizer and an inert, dipolar aprotic cosolvent, optionally to add an inert organic solvent of low or zero polarity to the reaction mixture present after the reaction, to add a non-aqueous base in an amount of 0.5 to 50% by weight, based on the cyclic anhydride of the formula (II) used, and to separate off the precipitate formed to give a filtrate containing the N-substituted cyclic imide.