Multigram Synthesis of Fluoroalkyl-Substituted Pyrazole-4-carboxylic Acids

Acylation of tert‐butyl 3‐(methylamino)but‐2‐enoate with fluorinated acetic acid anhydrides occurred at the enamine carbon atom. The reaction of the resulting tert‐butyl 3‐(methylamino)‐2‐(RFCO)but‐2‐enoates with alkyl hydrazines resulted in mixtures of isomeric pyrazoles that were easily separated...

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Bibliographic Details
Published in:	European journal of organic chemistry Vol. 2015; no. 4; pp. 886 - 891
Main Authors:	Iminov, Rustam T., Mashkov, Alexander V., Vyzir, Ivan I., Chalyk, Bohdan A., Tverdokhlebov, Anton V., Mykhailiuk, Pavel K., Babichenko, Ludmila N., Tolmachev, Andrey A., Volovenko, Yulian M., Biitseva, Angelina, Shishkin, Oleg V., Shishkina, Svetlana V.
Format:	Journal Article
Language:	English
Published:	Weinheim WILEY-VCH Verlag 01-02-2015 WILEY‐VCH Verlag Wiley Subscription Services, Inc
Subjects:	Acids Acylation Carboxylic acids Chromatography Cyclization Fluorine Nitrogen heterocycles
Online Access:	Get full text
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Summary:	Acylation of tert‐butyl 3‐(methylamino)but‐2‐enoate with fluorinated acetic acid anhydrides occurred at the enamine carbon atom. The reaction of the resulting tert‐butyl 3‐(methylamino)‐2‐(RFCO)but‐2‐enoates with alkyl hydrazines resulted in mixtures of isomeric pyrazoles that were easily separated by column chromatography. The target fluorinated pyrazole‐4‐carboxylic acids were obtained on a multigram scale. Fluorinated pyrazolecarboxylic acids ― potential building blocks for agrochemical applications ― have been prepared on a multigram scale. The easy separation of the isomeric mixture of esters was the key feature of the synthesis.
Bibliography:	ark:/67375/WNG-9S94B7RH-7 istex:B51EDE77AFD62A082251DA2A5128633A1AD7622A ArticleID:EJOC201403295
ISSN:	1434-193X 1099-0690
DOI:	10.1002/ejoc.201403295