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:
Apr. 20, 1982
Filed:
Jul. 25, 1979
Hans-Joachim Herrmann, Troisdorf, DE;
Dynamit Noble Aktiengesellschaft, Troisdorf, DE;
Abstract
In a process for the hydrogenation of nitrobenzene with hydrogen to hydrazobenzene at temperatures ranging from 40.degree. to 110.degree. C. in the presence of a precious metal catalyst, an aqueous alkaline solution and an organic solvent, the reaction mixture being maintained in turbulent motion, the improvement wherein said nitrobenzene is o-, m- or p-chloronitrobenzene, the reaction is carried out in an organic solvent in which the dichlorohydrazobenzene being formed is readily soluble when warm and difficultly soluble when cold, and that the precious metal catalyst is used in such amount that the weight ratio of chloronitrobenzene used to precious metal catalyst is in the range 1:0.00005-less than 0.0002.