Unexpected Metal-Free Fluorination and Oxidation at the C-4 Position of Pyrazoles Promoted by Selectfluor

Bonacorso, Hélio G.; Pittaluga, Everton P.; Porte, Liliane M. F.; Libero, Francieli M.; Junges, Andrizia F.; Zanatta, Nilo; Martins, Marcos A. P.

doi:10.1055/s-0034-1381050

Cited by 7 publications

(1 citation statement)

References 12 publications

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“…In 2015, Bonacorso and collaborators mentioned that heating of 4-hydroxymethylpyrazoles with Selectfluor in acetonitrile unexpectedly gave 4-fluoropyrazoles. 34 In fact, pyrazoles of type 16−18 were isolated in 47−63% yield (Scheme 4). It is worth noting that the reaction did not require any metal catalysis.…”

Section: Oxidative Fluorination Of Pyrazolesmentioning

confidence: 99%

Fluorinated Pyrazoles: From Synthesis to Applications

2020

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Fluorinated pyrazoles play an important role in medicinal chemistry, drug discovery, agrochemistry, coordination chemistry, and organometallic chemistry. Since the early 1990s, their popularity has grown exponentially. Moreover, more than 50% of all contributions on the topic have been published in the last 5 years. In this review, analysis of novel synthetic approaches to fluorinated pyrazoles that appeared in recent years is performed. A particular emphasis is devoted to a detailed consideration of reaction mechanisms. In addition, the reasons that have led to the ever-increasing popularity of fluorinated pyrazoles in various areas of science are discussed. At the end of the review, several potentially interesting but yet mostly unknown classes of fluorinated pyrazoles are outlined.

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Section: Oxidative Fluorination Of Pyrazolesmentioning

confidence: 99%

Fluorinated Pyrazoles: From Synthesis to Applications

2020

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Antispasmodic and antimicrobial activities of pyrazole‐containing ferrocenyl alkanols versus their phenyl analogs, and the entry point to potential multitarget treatment for inflammatory bowel diseases

Radulović

Nikolić

Mladenović

et al. 2021

Applied Organom Chemis

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Inflammatory bowel diseases (IBM), such as Crohn's disease, and their common complications represent a global health challenge. Many pyrazole derivatives, such as the spasmolytic drug metamizole, have already found their place among the frequently used therapeutic agents. Alteration of the structure of established therapeutic drugs by introducing a ferrocene moiety was shown to be a promising way for the discovery of new drugs. Herein, two libraries of analogous ferrocenyl (1a‐1j) and phenyl alkanols (2a‐2j) containing a pyrazole core, among which 17 completely new structures, have been synthesized, and structurally and electrochemically characterized. These compounds, along with the aldehydes used for their synthesis, were tested in parallel for their antispasmodic, acetylcholinesterase‐inhibitory, and antimicrobial activities to evaluate their potential as multitarget IBM drugs. The antispasmodic activity was investigated by assessing their effect on both the amplitude and number of spontaneous contractions of isolated rat ileum. Their antimicrobial effect was evaluated against a panel of Gram‐positive and Gram‐negative bacterial strains and fungi. It was found that several of the evaluated compounds displayed gastrointestinal smooth muscle relaxant activity, among them, 1‐(1H‐3‐ferrocenyl‐1‐phenylpyrazol‐4‐yl)‐3‐methylbutan‐1‐ol (1d) showed a remarkable effect by superseding the activity of papaverine. Together with the fact that it represents one of the most antimicrobially active investigated compounds, 1d is a good candidate for further pharmacological evaluation as a multitarget drug for IBM.

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