Pyrimidines
Mostrando 1-12 de 365 artigos, teses e dissertações.
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1. 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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2. CHEMICAL CONSTITUENTS DERIVED FROM THE CANARIES MARINE SPONGE Myxilla sp.
Stigmasterols, ceramides, including ceramide-1-phosphates and pyrimidines were identified in an ethanol extract of the marine sponge Myxilla sp. The compounds were identified by MS and 1D- and 2D-NMR techniques. A simple method based on an ultra-high-performance liquid chromatography coupled with tandem mass spectrometry was developed to investigate the prod
Quím. Nova. Publicado em: 2018-03
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3. Vasoactive Thiomethyl-Pyrimidines: Promising Drug Candidates with Vascular Activity
Pyrimidines and their derivatives are present in various biologically active molecules. Most of the synthetic methods employed to achieve the pyrimidinone ring consist of two stages: the synthesis of a Michael intermediate from an aldehyde and an "active methylene" containing compound; and the condensation of this intermediate with a molecule containing an u
J. Braz. Chem. Soc.. Publicado em: 2017-07
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4. 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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5. Efficient synthesis of new biheterocyclic 5-[(5-Trifluoromethyl-5-hydroxy-4,5-dihydro-1H-pyrazol-1-yl)-1-propan-1-one-3-yl]-2-methyl-7-trifluoromethylpyrazolo[1,5-a]pyrimidines
Neste trabalho relatamos a ciclocondensação entre a 2-metil-7-trifluorometilpirazolo[1,5-a]pirimidino-5-propanoil hidrazida derivada da 2-metil-5-(metilpropanoato-3-il)-7-trifluorometilpirazolo[1,5-a]pyrimidina e doze versáteis 1,1,1-trifluoro-4-alcóxi-3-alquen-2-onas [F3CC(O)C(R²)=C(R¹)OMe onde R¹ = H, Me, (CH2)2CHCMe2, (CH2)2Ph, (CH2)2CO2Me, Ph, 4-M
J. Braz. Chem. Soc.. Publicado em: 2014-08
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6. 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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7. 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
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8. Synthesis of 6-methylsubstituted 2-phenyl-3H-pyrimidin-4-ones and 4-trifluoromethyl-2-ureido pyrimidines / Síntese de 2-fenil-3H-pirimidin-4-onas 6-metilsubstituídas e 4- trifluormetil-2-ureído pirimidinas
This study was carried out in three parts: At first, three methods for the bromination of 6-alkylsubstituted 2-phenyl-3H-pyrimidin-4-ones was developed for the synthesis of: (i) a new series of 6-alkylsubstituted 5-bromo-2-phenyl-3H-pyrimidin-4-ones, (ii) a new series of 6-(1-bromoalkyl)-2-phenyl-3H-pyrimidin-4-ones, and (iii) e new series of 5-bromo-6-(1-br
Publicado em: 2009
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9. SYNTHESIS OF 1,2,4-TRIAZOL-5-YLAMINO PYRIMIDINES TRIFLUOROMETHYL SUBSTITUTED / SÍNTESE DE 1,2,4-TRIAZOL-5-ILAMINO PIRIMIDINAS TRIFLUORMETIL SUBSTITUÍDAS
This work describes the synthesis and characterization of fourteen 4-trifluoromethyl-2-[3-(pyridyl)-1H-1,2,4-triazol-5-ylamino]pyrimidines (6, 7), from the cyclocondensation reaction of N-[3-(pyridyl)-1H-1,2,4-triazol-5-yl]guanidines (4, 5), a 1,3-dinucleophile precursor of the type (N-C-N), with 1,1,1-trifluoro-4-alkoxy-3-alken-2-ones (1), a versatile 1,3-d
Publicado em: 2009
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10. Acilenaminonas: Síntese e Aplicação na Obtenção de Pirazóis, Pirazolo[3,4-d]piridazinonas e Pirazolo[1,5-a]pirimidinas / Acylenaminones: Synthesis and Application in the Obtaining of Pyrazoles, Pyrazolo[3,4-d]pyridazinones and Pyrazolo[1,5-a]pyrimidines
The regioespecific synthesis of a series of 14 N-acylated enaminones (52-88%) from the acylation reaction of secondary -enamino ketones [RC(O)CH=CHNR1R2; R = Ph, 4- FC6H4, 4-NO2C6H4, thien-2-yl, CCl3, CF3; R1 = H; R2 = Bn, Ph, 4-NO2C6H4] with trifluoroacetic anhydride or ethyl oxalyl chloride in pyridine is reported. On the other hand, when tertiary enaminon
Publicado em: 2009
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11. 2-methyl-7-substituted pyrazolo[1,5-a]pyrimidines: highly regioselective synthesis and bromination
Este trabalho descreve a reação de ciclocondensação de 3-amino-5-metil-1H-pirazol com 1,1,1-tricloro-4-alcóxi-3-alquen-2-onas [CCl3C(O)CH=C(R¹)OR, onde R¹/R = H/Me, Me/Et, Et/Me, Pr/Et, Bu/Me, iso-Bu/Me] e β-dimetilaminovinil cetonas [R²C(O)CH=CHNMe2, onde R² = Ph, Ph-4-Me, Ph-4-F, Ph-4-Cl, Ph-4-Br, Ph-4-NO2, fur-2-il, tien-2-il, pirrol-2-il, pyrid
Journal of the Brazilian Chemical Society. Publicado em: 2009
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12. SÍNTESE DE HETEROCICLOS VIA REAÇÕES DE CICLOCONDENSAÇÃO DE a-ETILOXALIL E -PIRAZOLIL(ALQUIL) b-DIMETILAMINOENONAS COM 1,2- OU 1,3-DINUCLEÓFILOS / SYNTHESIS OF HETEROCYCLES VIA CYCLOCONDENSATION REACTIONS OF a-ETHYLOXALYL AND -PYRAZOLYL(ALKYL) b-DIMETHYLAMINOENONES WITH 1,2- OR 1,3-DINUCLEOPHILES
Chemoselective synthesis of ethyl 4-pirimidinecarboxylates and/or ethyl 5-pirimidineoxalates via cyclocondensation reaction of b-dimethylaminoenones [R1C(=O)C(=CNMe2)C(=O)CO2Et, where R1 = Ph, 4-MeC6H4, 4-MeOC6H4, 4-BrC6H4, 4-ClC6H4, 4-FC6H4, 4-O2NC6H4, 2-thienyl, benzo[b]furan-2-yl and CF3] with NCN 1,3- dinucleophiles such as benzamidine hydrochloride or 1
Publicado em: 2009