Heterocycles
Mostrando 1-12 de 57 artigos, teses e dissertações.
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1. Sustainable and Reusable Sulfonic Acid-Functionalized Task-Specific Ionic Liquid Catalysts for Multicomponent Reactions. A Review
Improvements in Sustainable Organic Synthesis are usually related to the investigation of less hazardous, non-corrosive and renewable materials, as well as waste prevention, energy efficiency, solvent-free reactions, and the development of efficient reusable catalysts. In this context, multicomponent reactions emerged as important strategies for the rapid an
Journal of the Brazilian Chemical Society. Publicado em: 2022
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2. A Green Procedure Using Disposable Pipette Extraction to Determine Polycyclic Aromatic Sulfur Heterocycles in Water Samples and Solid Petrochemical Residues
A simple and efficient method using reduced amounts of solvents for the determination of polycyclic aromatic sulfur heterocycles (PASHs) in aqueous matrices from a lagoon and leachate solid waste from a petrochemical industry is proposed. The target analytes were previously concentrated using the disposable pipette extraction (DPX) technique applying gas chr
J. Braz. Chem. Soc.. Publicado em: 2021-02
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3. A Comparative Study on the Groebke-Blackburn-Bienaymé Three-Component Reaction Catalyzed by Rare Earth Triflates under Microwave Heating
Over the last twenty years, the Groebke-Blackburn-Bienaymé (GBB) reaction has been emerged as a powerful tool to access different nitrogen-based heterocycles as privileged scaffolds in medicinal chemistry. This multicomponent reaction is usually catalyzed by ordinary Brønsted or Lewis acid catalysts. Herein, we present a comparative study on the catalytic
J. Braz. Chem. Soc.. Publicado em: 2020-07
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4. Exploring the metallochromic behavior of pentacyanidoferrates in visual, electronic and Raman spot tests
Abstract: Pentacyanidoferrate(II) complexes of aromatic N-heterocycles, such as 4-cyanopyridine, exhibit characteristic colors and strong metallochromism associated with the donor-acceptor interactions of the metal ions with the cyanide ligands. In the presence of transition metal ions insoluble polymeric complexes are formed, displaying bright yellow, red,
An. Acad. Bras. Ciênc.. Publicado em: 25/04/2019
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5. Synthesis and antimicrobial activity of new amino derivatives of pyrano[4’’,3’’:4’,5’]pyrido[3’,2’:4,5]thieno[3,2-d]pyrimidine
ABSTRACT Annulated thienopyrimidine derivatives attracted big interest of the scientific community due to their broad spectrum of biological activities among which are the inhibition of phosphodiesterase, antiproliferative and antimicrobial activities. As a continuation of our studies on the synthesis and biological activity of fused thieno[3,2-d]pyrimidine
An. Acad. Bras. Ciênc.. Publicado em: 23/04/2018
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6. Brønsted Acid-Catalyzed Dipeptides Functionalization through Azlactones
Azlactones are useful building blocks in the synthesis of functional amino acid derivatives, heterocycles and bioactive molecules. In this work, a protocol for the organocatalytic functionalization of dipeptides has been presented. 2-Alkyl-substituted azlactone intermediates in the presence of different amines and alcohols were combined in a ring opening rea
J. Braz. Chem. Soc.. Publicado em: 2017-07
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7. Synthesis of Novel 2-Aryl-3-(2-morpholinoethyl)-1,3-thiazinan-4-ones Via Ultrasound Irradiation
This study describes the synthesis of fourteen thiazinanones from a multicomponent reaction of 2-morpholinoehtylamine (as primary amine), arenealdehydes (as carbonyl compound) and the mercaptopropionic acid using both conventional (thermal heating) and ultrasound methodologies. Through thermal heating methodology, the thiazinanones were obtained in 49 to 97%
J. Braz. Chem. Soc.. Publicado em: 2016-06
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8. Synthesis and Antitumor Evaluation of New Heterocycles Derived from 3-Methyl-2-benzothiazolinone Hydrazone
3-Methyl-2-benzothiazolinone hydrazone condensed with some selected aldehydes to give the corresponding Schiff bases. Cyclizing the obtained Schiff base derivatives with thioglycolic acid afforded the respective thiazolylideneaminothiazolidenones. Condensation of 3-methyl-2-benzothiazolinone hydrazone with ethyl cyanoacetate yielded a mixture of the bishydra
J. Braz. Chem. Soc.. Publicado em: 2015-06
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9. Microwave-assisted synthesis of N-heterocycles and their evaluation using an acetylcholinesterase immobilized capillary reactor
Os etenoditioacetais polarizados são conhecidos como importantes intermediários em muitos processos de síntese. Neste trabalho, reporta-se a anelação livre de metal de transição de 1,1-bis(tiometil)-2-nitroetileno com hidroxilalquilaminas e alquildiaminas. Esta metodologia permite a síntese direta de N-heterociclos tais como imidazolidinas, oxazolidi
J. Braz. Chem. Soc.. Publicado em: 2014-05
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10. Síntese de heterociclos bioativos derivados do ferroceno
The discovery of ferrocene marked one of the points of departure for modern organometallic chemistry. In general, the compounds of ferrocene derivatives are widely applied in several areas. One of the most important applications of ferrocene is the development of more active drugs, especially in cases where there is resistance to current drugs. Bioactive age
Quím. Nova. Publicado em: 2013
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11. Reações de 2-alcóxi-5-trifluoracetil-3,4-diidro-2H-piranos com etilaminas substituídas e arilaminas / Reactions of 2-alkoxy-5-trifluoroacetyl-3,4-dihydro-2H-pyrans with substituted ethylamines and arylamines
Este trabalho apresenta a síntese de duas séries inéditas de 1-alquil(aril)-2- amino-5-trifluoracetil-1,2,3,4-tetraidropiridinas (6,8), obtidas a partir da reação de 2- alcóxi-5-trifluoracetil-3,4-diidro-2H-piranos (alcóxi = MeO (3), EtO (4)) com etilaminas primárias, de fórmula geral R1CH2CH2NH2, onde R1 = 2-MeO-Ph (5a), 4- MeO-Ph (5b), 3,4-OMe-Ph
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 25/02/2011
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12. Irradiação de micro-ondas aplicada à síntese orgânica: uma história de sucesso no Brasil
This review article shows the publications in the field of microwave irradiation published by Brazilian researchers over the past 10 years. In South America, Brazil leads the publication of articles with the use of microwave irradiation possessing a large advantage in number of articles published over the others countries. The works were divided into four ma
Química Nova. Publicado em: 2011