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:
Aug. 20, 1991
Filed:
Jun. 21, 1989
Klaus Warning, Eppstein/Taunus, DE;
Kurt Habig, Morfelden-Walldorf, DE;
Hoechst Aktiengesellschaft, Frankfurt am Main, DE;
Abstract
Process for the preparation of 4-chloro-2,5-dimethoxyaniline by catalytic reduction of 4-chloro-2,5-dimethoxynitrobenzene with hydrogen in the liquid phase at an elevated temperature and elevated pressure, which comprises carrying out the reduction at temperatures from about 80.degree. to about 110.degree. C. and under a pressure of about 5 to 50 atmospheres gauge in an aromatic solvent in the presence of a modified platinum-on-carbon catalyst in the presence of about 0.01 to about 0.2 mole of a compound which gives a pH of 8 to 10 in aqueous solution, and in the presence of about 0.1 to about 1.0% by weight of an aliphatic, open-chain, primary, secondary or tertiary amine or a cyclic amine, in each case relative to the amount in moles and weight, respectively, of 4-chloro-2,5-dimethoxynitrobenzene employed.