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. 23, 1991
Filed:
Sep. 13, 1989
Applicant:
Inventors:
Michael Yelland, Rossendale, GB;
John Conway, Manchester, GB;
Assignee:
Imperial Chemical Industries PLC, London, GB;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
544239 ;
Abstract
Improved method for the manufacture of plant regulant pyridazine-4-one carboxylic acids, which comprises the step of decarboxylating a 4-oxo-3, 5-pyridazine dicarboxylic acid to give a 4-oxo-5-pyridazine carboxylic acid by treatment with 95-100% sulphuric acid at 160.degree.-180.degree. C. using a reactant; acid weight ratio of about 1:4 to 1:10.