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:
May. 12, 1987
Filed:
Nov. 18, 1985
Chiraranjan Podder, Dormagen, DE;
Harro Schlesmann, Odenthal, DE;
Bayer Aktiengesellschaft, Leverkusen, DE;
Abstract
An improved process for the preparation of 4-nitrodiphenylamines by the reaction of 4-nitrohalobenzenes with primary aromatic amines in the presence of potassium carbonate and copper compounds is characterized in that sulpholane dimethylsulphone, dimethylacetamide, diethylacetamide, tetramethylurea, tetraethylurea or mixtures thereof are used as solvents and 3 to 5 mol of amine are used per mol of halogenated nitrobenzene, from 1.2 to 2 mol of said amine being added before the beginning of the reaction and the remainder during the reaction at such a rate that the molar excess of unreacted amine over unreacted halogenated nitrobenzene is constantly at least 100%.