Cyclocondensation Reaction
Mostrando 1-12 de 26 artigos, teses e dissertações.
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1. Ultrasound-Promoted Synthesis, Structural Characterization and in vitro Antimicrobial Activity of New 5-Aryl-3-(2-hydroxyphenyl)-4,5-dihydro-1H-pyrazole-1-carboximidamides
This work aims the synthesis of amidino pyrazolines by the cyclocondensation reaction between 3-(hetero)aryl-1-(2-hydroxyphenyl)enones and aminoguanidine hydrochloride under sonochemical conditions. Thirteen new compounds were synthesized in 15-83% of yield after sonication for 30 min without purification by chromatography. Furthermore, antimicrobial activit
J. Braz. Chem. Soc.. Publicado em: 2020-04
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2. 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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3. Streamlined Synthesis of 6-((1H-1,2,3-Triazol-4-yl)methyl)-1H-pyrrolo [3,4-d]pyridazin-1-one System via Sequential N-Alkylation, CuAAC, and [4 + 2] Cyclization Reactions
An efficient sequential three-step reaction methodology for the synthesis of three new series-1-(prop-2-yn-1-yl)-1H-pyrroles, methyl 4-acetyl-1-((1H-1,2,3-triazol-4-yl)methyl)-1H-pyrrole-3-carboxylates and 6-((1H-1,2,3-triazol-4-yl)methyl)-2,6-dihydro-1H-pyrrolo[3,4-d]pyridazin-1-ones-is reported. The methodology comprises: (i) N-alkylation reactions of poly
J. Braz. Chem. Soc.. Publicado em: 23/05/2019
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4. Ultrasound-Promoted Synthesis of 3-(Thiophen-2-yl)-4,5-dihydro-1H-pyrazole-1-carboximidamides and Anticancer Activity Evaluation in Leukemia Cell Lines
3-(Thiophen-2-yl)-4,5-dihydro-1H-pyrazole-1-carboximidamides were efficiently prepared through a cyclocondensation of thiophenylchalcones with aminoguanidine hydrochloride under ultrasonic conditions in the presence of KOH and ethanol as a green solvent in short reaction times (15-35 min) and good yields (62-95%). All compounds produced were evaluated agains
J. Braz. Chem. Soc.. Publicado em: 2017-02
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5. Synthesis, Structure Elucidation, Antioxidant and Antimicrobial Activity of Novel 2-(5-Trifluoromethyl-1H-pyrazol-1-yl)-5-(5-trihalomethyl-1H-pyrazol-1-yl-1- carbonyl)pyridines
This paper describes an efficient approach for the synthesis of a novel series of sixteen 2-(5-trifluoromethyl-1H-pyrazol-1-yl)-5-(5-trihalomethyl-1H-pyrazol-1-yl-1-carbonyl) pyridines, for the first time with non-identical substituents in both pyrazole rings, through the cyclocondensation reaction of 4-methoxy-4-alkyl(aryl/heteroaryl-1,1,1-trihaloalk-3-en-2
J. Braz. Chem. Soc.. Publicado em: 2015-11
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6. Synthesis of 4-Arylselanylpyrazoles Through Cyclocondensation Reaction Using Glycerol as Solvent
We describe here a simple method to synthesize 4-arylselanylpyrazoles by reaction of α-arylselanyl-1,3-diketones with arylhydrazines using glycerol as solvent at 60 °C under N2 atmosphere. This is a direct cyclocondensation reaction performed with α-arylselanyl-1,3-diketones and arylhydrazines bearing electron-withdrawing and electron-donating groups a
J. Braz. Chem. Soc.. Publicado em: 2015-08
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7. 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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8. SÍNTESE DE 1-ARIL-4-[(DIMETILAMINO)METILENO] PIRROLIDINO-2,3,5-TRIONAS UTILIZANDO IRRADIAÇÃO DE MICRO-ONDAS / MICROWAVE-ASSISTED SYNTHESIS OF 1-ARYL-4 [(DIMETHYLAMINO) METHYLENE] PYRROLIDINE-2,3,5-TRIONE
A síntese de uma série de 4-(dimetilamino)metileno-1-aril-pirrolidino-2,3,5-triona foi realizada a partir da reação de ciclocondensação da b-enaminodicetona [Cl3C(O)C(=CHNMe2)C(O)CO2Et] com derivados da anilina [R = Ph, 3-Me-C6H4, 3- MeO-C6H4, 3-HO-C6H4, 4-Me-C6H4, 4-F-C6H4, 4-Cl-C6H4, 4-Br-C6H4, 4-O2N-C6H4, 4- MeCO-C6H4]. As condições reacionais uti
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 24/02/2011
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9. Simultaneous regioselective synthesis of trifluoromethyl-containing 1,7-phenanthrolines and quinolines from cyclocondensation reaction of N,N'-bis(oxotrifluoroalkenyl)-1,3-phenylenediamines
Este trabalho relata interessantes resultados relativos a síntese convencional de uma nova série de 2,10-dialquil(aril)-4,8-bis (trifluorometil)-1,7-fenantrolinas, em rendimentos de 22-40%, a partir das reações de ciclização de N,N'-bis(oxotrifluoralquenil)-1,3-fenilenodiaminas [1,3-C6H4-(NHCR=CHC(O)CF3)2] em um meio fortemente ácido (PPA) e na ausên
Journal of the Brazilian Chemical Society. Publicado em: 2011-08
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10. 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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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. 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