PREPARATION OF ALKYL 3-DIFLUOROMETHYL-1-METHYL-1H-PYRAZOLE-4-CARBOXYLIC ACID ESTER

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 aci...

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Bibliographic Details
Main Authors WANG, ZHEQING, WANG, ANGANG
Format Patent
LanguageEnglish
French
German
Published 09.12.2015
Subjects
ACYCLIC OR CARBOCYCLIC COMPOUNDS
CHEMISTRY
HETEROCYCLIC COMPOUNDS
METALLURGY
ORGANIC CHEMISTRY
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Summary: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 Na2CO3 or K2CO3.
Bibliography:Application Number: EP20140701138