Novel pyrazoles and isoxazoles were synthesized from the reaction of the carbanions of 1-aryl-2-(phenylsulphonyl)-ethanone with different hydrazonyl halides and 1-aryl-2-bromo-2-hydroximinoethanone in ethanol, respectively. Reactions were carried out under silent and ultrasonic conditions. In general, it was found that ultrasound irradiations enable some reactions to occur which could not be carried out under silent condition in addition to improvement in reaction times. The products were obtained in high yields and their structures were determined by elemental analyses, spectral data and X-ray diffraction.
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http://dx.doi.org/10.1016/j.ultsonch.2008.07.012 | DOI Listing |
Eur J Med Chem
January 2025
Key Laboratory for Green Chemical Process of Ministry of Education, Hubei Key Laboratory of Novel Reactor and Green Chemical Technology, Hubei Engineering Research Center for Advanced Fine Chemicals, School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, 206 1st Rd Optics Valley, East Lake New Technology Development District, Wuhan, Hubei, 430205, China. Electronic address:
The growing prevalence of microbial infections, and antimicrobial resistance (AMR) stemming from the overuse and misuse of antibiotics, call for novel therapeutic agents, particularly ones targeting resistant microbial strains. Scientists are striving to develop innovative agents to tackle the rising microbial infections and abate the risk of AMR. Pyrazole, a five-membered heterocyclic compound belonging to the azole family, is a versatile scaffold and serves as a core structure in many drugs with antimicrobial and other therapeutic effects.
View Article and Find Full Text PDFChemMedChem
November 2024
Department of Chemistry of Bioactive Nitrogen-Containing Heterocyclic Bases, V. P. Kukhar Institute of Bioorganic Chemistry and Petrochemistry of the NAS of Ukraine, Academika Kukharya Str. 1, 02094, Kyiv, Ukraine.
Nature
November 2024
Institute of Organic Chemistry, RWTH-Aachen University, Landoltweg 1, Aachen, Germany.
Thiazoles and isothiazoles are privileged motifs in drug and agrochemical discovery. The synthesis of these derivatives is generally approached, designed and developed on a case-by-case basis. Sometimes, the lack of robust synthetic methods to a given target can pose significant difficulties or even thwart the preparation of specific derivatives for further study.
View Article and Find Full Text PDFJ Agric Food Chem
November 2024
State Key Laboratory of Green Pesticides, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China.
In recent years, isoxazole insecticides or parasiticides targeting the γ-aminobutyric acid receptor, such as fluralaner or fluxametamide, featured a novel chemical structure and exhibited potent insecticidal activity with no-cross resistance. Thus, many research institutes have tried to modify the structures of these agents to find a new insecticide. Previously, the majority of researchers stuck to the "phenyl-isoxazole-phenyl" structure, making modifications only to other components.
View Article and Find Full Text PDFChembiochem
December 2024
Núcleo de Química de Heterociclos (NUQUIMHE), Departamento de Química, Universidade Federal de Santa Maria, 97105-900, Santa Maria, RS, Brasil.
This study reports the synthesis of a new series of pyrazole-isoxazolines, at very good yields, from the cyclocondensation reaction of pyrazole-enaminones with hydroxylamine hydrochloride. Dehydration of the pyrazole-isoxazolines furnished another new series of the respective pyrazole-isoxazoles, at excellent yields. Both series of the obtained compounds were screened for antimycobacterial activity, and compounds 4 f and 5 c showed significant inhibition of bacterial growth with a time- and concentration-dependent bactericidal effect.
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