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. 22, 1994
Filed:
Feb. 01, 1993
Manfred J Bergfeld, Erlenbach-Mechenhard, DE;
Norbert Gutlein, Oberhofen, DE;
Klaus Wohlfahrt, Elsenfeld, DE;
Eberhard Aust, Grossostheim, DE;
Akzo N.V., Arnhem, NL;
Abstract
In a process for the preparation of 2-mercaptobenzothiazole from aniline, sulfur and carbon disulfide under pressure and for separation of the 2-mercaptobenzothiazole from the crude reaction product by cooling and recycling the desirable intermediates and by-products into the reactor together with aniline, sulfur and carbon disulfide, the reaction is carried out using a residence time in the reactor of at least one hour to a time before the 2-mercaptobenzothiazole product thus-formed begins to decompose into undesirable intermediate products. A maximum hydrogen sulfide pressure is maintained on quenching to a temperature ranging between 220 and 280.degree. C. by mixing the crude reaction product with carbon disulfide at a temperature sufficient to obtain a homogeneous quenched mixture. The hydrogen sulfide is removed completely only after crystallization of the 2-mercaptobenzothiazole.