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. 09, 1991
Filed:
Oct. 19, 1989
Richard B Lund, Jackson, AL (US);
Glenn W Brown, Wagarville, AL (US);
Ciba-Geigy Corp., Ardsley, NY (US);
Abstract
2-(stilbyl-4')-(naphtho-1',2':4,5)-1,2,3-triazole-2'-sulfonic acid is obtained by diazotizing p-aminostilbene sulfonic acid, coupling the resulting diazonium salt with Tobias acid and then oxidizing the resulting monoazo sodium salt to close the ring and form the naphthotriazolyl moiety, and, more particularly, by performing the ring-closure oxidation step in a solution of the monoazo compound in a mixture of 2-butoxyethanol and water with pressurized air by contacting said solution in the presence of a copper salt catalyst at temperatures in the range 105.degree.-160.degree. C. and at pressures in the range 10-80 psig, for a time sufficient to effect ring-closure.