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:
Sep. 03, 2002
Filed:
Feb. 09, 2001
Applicant:
Inventors:
Nikolaus Müller, Monheim, DE;
Michael Matzke, Wuppertal, DE;
Assignee:
Bayer Aktiengesellschaft, Leverkusen, DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
C07D / ;
Abstract
1-Alkyl-pyrazole-5-carboxylic esters are obtained with surprisingly low proportions of 1-alkyl-pyrazole-3-carboxylic esters if a 2,4-diketo ester and/or an enolate thereof is reacted with an alkylhydrazine and/or a corresponding alkylhydrazinium salt, if appropriate, in the presence of a solvent and/or of water, in such a manner that during at least about 90% of the reaction free alkylhydrazine is present.