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:
Nov. 02, 1999
Filed:
Jan. 08, 1998
Applicant:
Inventors:
Nikolaus Muller, Monheim, DE;
Lutz Heuer, Dormagen, DE;
Johannes Kanellakopoulos, Dormagen, DE;
Andreas Sattler, Dusseldorf, DE;
Klaus-Peter Heise, Odenthal, DE;
Assignee:
Bayer Aktiengesellschaft, Leverkusen, DE;
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
5483741 ;
Abstract
1-alkyl-pyrazole-5-carboxylic acid esters are prepared by reacting the enolate of a 2,4-diketocarboxylic acid ester with an N-alkylhydrazinium salt in the presence of a solvent. This process allows a particularly economic preparation of 1-alkyl-pyrazole-5-carboxylic acid esters in a simple manner and with only little formation of undesirable isomers.