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. 21, 1984
Filed:
Feb. 07, 1983
Richard B Lund, Jackson, AL (US);
Glenn W Brown, Wagarville, AL (US);
Ciba-Geigy Corporation, Ardsley, NY (US);
Abstract
An improved synthesis of the bacteriostat 2,4,4'-trichloro-2'-hydroxydiphenylether is disclosed wherein the hydrolysis after diazotization is carried out at 175.degree.-180.degree. C. to increase the yield and reaction rate. The hydrolyzed product is distilled after neutralization to remove the major portion of undesirable colored products and phenolics. The distillate is then extracted with tetrachlorethylene to separate the product from non-phenolic by-products including the 25-28% 2,4,8-trichlorodibenzofuran which are present. The final product of the process then meets F.D.A. and commercial standards for use in soaps and cosmetics.