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:
Feb. 23, 1993
Filed:
Mar. 13, 1992
Applicant:
Inventors:
Brian G Cox, Cheshire, GB;
Michael S Howarth, Lancashire, GB;
Assignee:
Imperial Chemical Industries PLC, London, GB;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
544239 ;
Abstract
A method for the preparation of a pyridazinone derivative having the general formula I: ##STR1## where: R.sup.1 is a phenyl group, optionally substituted, R.sup.2 is H, alkyl or carboxy, R.sup.3 is H, alkyl or alkoxy and R.sup.4 is alkyl; said method comprising reacting a hydrazone of glyoxylic acid halide having the formula VII: ##STR2## in which X is halogen, with an ester of formula VIII; ##STR3## in the presence of an alkaline earth base.