Publication

Fluorine-sacrificial cyclizations as an access to 5-fluoropyrazoles

Manfred Schlosser
2000
Journal Articles

Abstract

Me 3-methoxy-2-trifluoromethylacrylate, readily prepd. by Wittig reaction from Me 3,3,3-trifluoropyruvate, has been treated with a no. of aryl(or heteroaryl)hydrazines. Under mild base catalysis, the resulting 3-hydrazinoacrylates undergo consecutive hydrogen fluoride elimination and intramol. nucleophilic addn. to afford Me 1-(hetero)aryl-5-fluoropyrazole-4-carboxylates. 5-Aminopyrazoles have been obtained by direct reaction of Me 5-fluoro-1-phenylpyrazole-4-carboxylate with lithium amides, whereas 5-fluoro-1-phenylpyrazole-4-carboxamides have been formed by condensation of 5-fluoro-1-phenylpyrazole-4-carboxylic acid with amines. [on SciFinder (R)]

Official source

https://infoscience.epfl.ch/entities/publication/8962a823-f0d6-4cf0-9d18-028941830fc5

About this result

This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.

Graph Chat

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.

Manfred Schlosser
2000
Journal Articles

Abstract

Official source

https://infoscience.epfl.ch/entities/publication/8962a823-f0d6-4cf0-9d18-028941830fc5

About this result

Related concepts (9)

Organolithium reagent

In organometallic chemistry, organolithium reagents are chemical compounds that contain carbon–lithium (C–Li) bonds. These reagents are important in organic synthesis, and are frequently used to transfer the organic group or the lithium atom to the substrates in synthetic steps, through nucleophilic addition or simple deprotonation. Organolithium reagents are used in industry as an initiator for anionic polymerization, which leads to the production of various elastomers.

Lithium aluminium hydride

Lithium aluminium hydride, commonly abbreviated to LAH, is an inorganic compound with the chemical formula or . It is a white solid, discovered by Finholt, Bond and Schlesinger in 1947. This compound is used as a reducing agent in organic synthesis, especially for the reduction of esters, carboxylic acids, and amides. The solid is dangerously reactive toward water, releasing gaseous hydrogen (H2). Some related derivatives have been discussed for hydrogen storage. LAH is a colourless solid but commercial samples are usually gray due to contamination.

N-Butyllithium

n-Butyllithium C4H9Li (abbreviated n-BuLi) is an organolithium reagent. It is widely used as a polymerization initiator in the production of elastomers such as polybutadiene or styrene-butadiene-styrene (SBS). Also, it is broadly employed as a strong base (superbase) in the synthesis of organic compounds as in the pharmaceutical industry. Butyllithium is commercially available as solutions (15%, 25%, 1.5 M, 2 M, 2.5 M, 10 M, etc.) in alkanes such as pentane, hexanes, and heptanes.

Related publications (2)

Fluorine-sacrificial cyclizations as an access to 5-fluoropyrazoles

Chat with Graph Search

Asymmetric Bio- and Organocatalysis: Historical Aspects and Concepts

Bridging the final gap in stereocontrolled Wittig reactions: methoxymethoxy-armed allylic phosphorus ylides affording conjugated dienes with high cis selectivity