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. 10, 1982
Filed:
Jun. 23, 1980
Sameeh S Toukan, Phoenixville, PA (US);
Piero Nannelli, King of Prussia, PA (US);
Pennwalt Corporation, Philadelphia, PA (US);
Abstract
A process for the purification of crude 2-mercaptobenzothiazole, prepared by reacting aniline, carbon disulfide and sulfur at elevated temperature and pressure is described. The process comprises the reaction of crude 2-mercaptobenzothiazole with 5-20%, preferably 10-12%, molar excess aqueous alkali metal hydroxide having a concentration of 3 to 20% by weight alkali metal hydroxide at 70.degree. to 90.degree. C. for 0.5-4 hours, with vigorous agitation, followed by filtration of the insoluble impurities and acidification of the filtrate with a non-oxidizing mineral acid, such as hydrochloric and sulfuric acids. The precipitated, filtered product is washed with water and collected in 98-100% yield and 95-98.5% purity.