Pyrazoles
Mostrando 1-12 de 41 artigos, teses e dissertações.
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1. Efficient Synthesis and Antimicrobial Activities of Long Alkyl Chain Trifluoromethyl-1H-pyrazol-1-(thio)carboxamides and Trifluoromethyl-1H-pyrazol-1-yl-thiazoles
The synthesis of 3-alkyl-5-trifluoromethyl-1H- pyrazole-1-carboxamides, 3-alkyl-5-trifluoromethyl-1H-pyrazole-1-thiocarboxamides, and 2-(3-alkyl-5-trifluoromethyl-1H-pyrazol-1-yl)-thiazoles derivatives are reported. [3 + 2] cyclocondensations for a series of long alkyl chain 1,1,1-trifluoro-4-methoxyalk-3-en-2-ones and semicarbazide or thiosemicarbazide were
J. Braz. Chem. Soc.. Publicado em: 2021-04
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2. Microwave Assisted Synthesis of Thiocarbamoylpyrazoles and Application as an Alternative Latent Fingermark Developers
Fingerprints are unique to each individual, contributing to human identification in forensic cases. The powder technique being widely used is considered one of the most important in latent fingermarks analysis. In this sense, the present work aimed to synthesize 1-thiocarbamoyl-4,5-dihydro-1H-pyrazoles and apply them as powder agents to develop latent finger
J. Braz. Chem. Soc.. Publicado em: 2020-06
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3. Oxone®-Promoted One-Pot Synthesis of 1-Aryl-4-(organylselanyl)-1H-pyrazoles
We describe herein an efficient protocol for the one-pot synthesis of 4-organylselanylpyrazoles by direct cyclocondensation and C-H bond selenylation reactions starting from hydrazines, 1,3-diketones and diorganyl diselenides promoted by Oxone®. The products were obtained through a metal catalyst free methodology, under mild conditions, in short reaction ti
J. Braz. Chem. Soc.. Publicado em: 21/10/2019
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4. Pyrazolyl-Tetrazoles and Imidazolyl-Pyrazoles as Potential Anticoagulants and their Integrated Multiplex Analysis Virtual Screening
This article reports a novel virtual screening algorithm seeking the rational identification of novel lead anticoagulants. Seven 5-(3-methyl-1-aryl-1H-pyrazol-4-yl)-1H-tetrazoles and seven novel 1-aryl-4-(4,5-dihydro-1H-imidazol-2-yl)-3-methyl-1H-pyrazoles were obtained in three steps starting from arylhydrazine hydrochlorides as raw materials in good yields
J. Braz. Chem. Soc.. Publicado em: 2019-01
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5. Straightforward and Clean Ultrasound-Promoted Synthesis of 2-(4,5-Dihydro‑1H‑pyrazol-1-yl)pyrimidines
A series of twelve novel 2-(pyrazol-1-yl)pyrimidine derivatives was easily obtained under ultrasonic conditions by the cyclocondensation reaction of 1-carboxamidino-pyrazoles with 4-methoxyvinyl-trifluoromethyl ketones using ethanol as an environment-friendly solvent in the presence of potassium hydroxide. Comparison of the ultrasound-promoted reaction with
J. Braz. Chem. Soc.. Publicado em: 2015-06
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6. Synthesis of fatty trichloromethyl-β-diketones and new 1H-pyrazoles as unusual FAMEs and FAEEs
A síntese eficiente de novas 1,1,1-tricloro-4-metoxi-3-alquen-2-onas graxas [Cl3CC(O)C(R²)=C(R¹)OMe, onde R¹ = n-hexil, heptil, nonil, undecil, tridecil e R² = H] e 1,1,1-tricloro-2,4-alkanediones [Cl3CC(O)CHR²C (O) R¹, onde R¹ = n-pentil e R² = Me, R¹ = Et e R² = n-butil, R¹ = n-butil e R² = n-propil] é apresentada, com bons rendimentos (85-95
J. Braz. Chem. Soc.. Publicado em: 2013-12
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7. Síntese de Pirimidinas derivadas de 7,7,7-trialo-4-metoxi-6-oxo-4- heptenoatos de metila e bi-heterociclos trifluormetilados / Synthesis of the Pyrimidines derivatives of methyl 7,7,7-trihalo-4- methoxy-6-oxo-heptenoates and bi-heterocyclic trifluoromethylated
Este trabalho descreve um método eficiente para a obtenção de pirimidinonas e pirimidinas trialometiladas a partir da reação de ciclocondensação [3+3] dos compostos (7,7,7-trialo-4-metoxi-6-oxo-4-heptenoatos de metila com uréia e diferentes amidinas fornecendo a série de pirimidinas e pirimidinonas 6-trifluormetil substituídas e 6- triclorometil su
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 27/02/2012
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8. ESTUDO DO COMPORTAMENTO QUÍMICO DE HETEROCICLOS TRIFLUORMETIL SUBSTITUÍDOS EM REAÇÕES COM DAST / STUDY OF THE CHEMICAL BEHAVIOR OF TRIFLUOROMETHYL SUBSTITUTED HETEROCYCLES IN REACTIONS WITH DAST
This work describes the study of the chemical behavior of trifluoromethyl substituted heterocycles as 1H-pyrazoles, 2-pyrazolines, 2H-cromenones and isoxazolines in reactions with DAST, with the aim of evaluating possible reactions in the oxygenated sites, aiming mainly the insertion of fluorine atoms in these molecules. Trifluoromethylated heterocycle precu
Publicado em: 2011
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9. Antipyretic and antioxidant activities of 5-trifluoromethyl-4,5-dihydro-1H-pyrazoles in rats
The objective of this study was to determine the effect of eight 5-hydroxy-5-trifluoromethyl-4,5-dihydro-1H-1-carboxyamidepyrazoles (TFDPs) on rat body temperature and baker’s yeast-induced fever. TFDPs or vehicle (5% Tween 80 in 0.9% NaCl, 5 mL/kg) were injected subcutaneously and rectal temperature was measured as a function of time in 28-day-old male Wi
Brazilian Journal of Medical and Biological Research. Publicado em: 2010-12
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10. 1-(2,4-dichlorophenyl-1H-pyrazoles: Synthesis, Structural Analysis and Interactions with Cannabinoid Receptors CB1 / 1-(2,4-Diclorofenil)-1H-pirazóis: Síntese, Análise Estrutural e Interação com os Receptores Canabinóides CB1
A method to obtain fourteen enones [EtO2CC(O)C(R2)=C(R1)OR, where R = H, Me; R1 = Pr, Ph, 4-MeOC6H4, 4-MeC6H4, 4-FC6H4, 4-ClC6H4, 4-BrC6H4, 4-NO2C6H4, Fur- 2-yl; R2 = H; R1,R2 = -(CH2)3-, -(CH2)4-, -(CH2)5-, -(CH2)6-, 3,4-dihydronaphthalen-2-yl] from acylation of acetals with ethyl oxalyl chloride is reported. The cyclocondensation reaction of these substrat
Publicado em: 2010
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11. NH-PIRAZÓIS E ISOXAZÓIS: SÍNTESE MECANICAMENTE ATIVADA POR GRINDING / NH-PYRAZOLES AND ISOXAZOLES: SYNTHESIS MECHANICALLY ACTIVATED BY GRINDING
The synthesis of twelve NH-pyrazoles from the cyclocondensation reaction of β-dimethylaminovinylketones ([R1C(O)C(R2)=CHN(Me)2], where R1 = Me, C6H5, 3- MeO-C6H4, 4-Me-C6H4, 4-MeO-C6H4, 4-F-C6H4, 4-Cl-C6H4, 4-Br-C6H4, 4-O2N-C6H4, fur-2-il, tien-2-il; R2 = H, 2-MeO-C6H4 and R1, R2 = -(CH2)3C(O)- with hydrazine sulfate is reported. In this work, it was al
Publicado em: 2010
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12. Aplicação de α-oxoceteno ditiocetais em síntese orgânica
The synthesis and reactivity of α-oxoketenes dithioacetals (S,S-acetals), general structure [(R¹C=OC(R²)=C(SR³)(SR4)], are reported. We also showed the application of S,S acetals as synthons for efficient synthesis of isoxazoles, pyrazoles, indazoles, thiophenes, dithiol thiones, pyridines, pyrimidines and other heterocycles. This work aims to review the
Química Nova. Publicado em: 2010