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:
Oct. 28, 2014
Filed:
Dec. 31, 2013
Applicant:
Kingchem Llc, Allendale Park, NJ (US);
Inventors:
Zheqing Wang, Union City, CA (US);
Angang Wang, Dalian, CN;
Assignee:
KingChem LLC, Allendale Park, NJ (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07C 67/343 (2006.01); C07D 231/14 (2006.01); C07C 67/313 (2006.01); C07C 67/36 (2006.01);
U.S. Cl.
CPC ...
C07D 231/14 (2013.01); C07C 67/313 (2013.01); C07C 67/36 (2013.01);
Abstract
The present disclosure provides a novel and economically advantageous process for preparation of compounds of Formula I, such as alkyl 3-difluoromethyl-1-methyl-1H-pyrazole-4-carboxylic acid ester. The process includes acidification of the sodium enolate of alkyl difluoroacetoacetate by carbonic acid generated in situ by reacting carbon dioxide with water. The disclosure also includes promoting the ring closure reaction in which alkyl 2-alkomethylene-4,4-difluoro-3-oxobutyrate is reacted with methylhydrazine in two phase system with a weak base such as NaCOor KCO.