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. 16, 2002
Filed:
Jan. 11, 2001
Applicant:
Inventor:
Douglas D. Burkett, Phoenix, AZ (US);
Assignee:
Zila, Inc., Phoenix, AZ (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
C07D / ;
Abstract
A process for synthesizing 2-amino-5-dimethlyaminophenyl thiosulfonic acid comprises the step of oxidizing N,N′-dimethyl-&rgr;-phenylene-diamine in the presence of a source of thiosulfate ions, while maintaining the temperature of the reaction mixture not higher than about 10° C. This compound is useful as an intermediate in the synthesis of toluidine blue O. A process for manufacturing toluidine blue O with improved yield, includes the step of preparing the intermediate 2-amino-5-diethylaminopropyl thiosulfonic acid according to the above described procedure.