Tetrahydrofuran
Mostrando 1-12 de 78 artigos, teses e dissertações.
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1. Ketones as Electrophile in Nitroaldol Reaction: Synthesis of β,β-Disubstituted- 1,3-dinitroalkanes and Allylic Nitro Compounds
Abstract β,β-Disubstituted-1,3-dinitro compounds were obtained exclusively with an overall yield of 83% through a domino nitroaldol/elimination/1,4-addition process, when excess nitromethane was added to cyclohexanone or butanone using DBU (1,8-diazabicyclo[5.4.0]undec-7-ene), as a basic catalyst. On the other hand, β-nitroalcohols could be obtained in 30
J. Braz. Chem. Soc.. Publicado em: 2021-08
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2. Synthesis, in silico Study and Antimicrobial Activity of New Piperine Derivatives Containing Substituted δ-Esters
A series of fifteen new piperine-derived diesters was synthesized through the substitution reaction between the salt of piperic acid, obtained through piperine basic hydrolysis, with the δ-chloro-esters, obtained through the cleavage of tetrahydrofuran (THF) with acyl chlorides in the presence of ZnCl2. The final compounds were obtained with yields ranging
J. Braz. Chem. Soc.. Publicado em: 2020-12
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3. Production of Medical Grade Silicone for Facial Prosthesis with Bactericidal Properties from the Inclusion of Poly (Diallyldimethylammonium Chloride): An in Vitro Study
Abstract Objective: To evaluate the inclusion capacity and bactericidal efficiency of diallyl dimethyl ammonium chloride (PDADMAC) diluted in tetrahydrofuran (THF) upon inclusion in the medical grade silicone polymer structure. Material and Methods: It was diluted the PDADMAC in THF at the concentration of 4wt%. It was included in the silicon paste during
Pesqui. Bras. Odontopediatria Clín. Integr.. Publicado em: 02/09/2019
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4. Production of Furan Compounds from Sugarcane Bagasse Using a Catalytic System Containing ZnCl2/HCl or AlCl3/HCl in a Biphasic System
In this work, two catalytic systems combining Lewis and Brønsted acids (ZnCl2/HCl and AlCl3/HCl) were applied in a tetrahydrofuran (THF)/NaClaq biphasic system to produce furan compounds from plant polysaccharides. The following cellulosic matrices were applied for this purpose: α-cellulose, microcrystalline cellulose and both native and steam-exploded sug
J. Braz. Chem. Soc.. Publicado em: 2018-05
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5. Development and validation of stability indicating liquid chromatographic (RP-HPLC) method for estimation of ubidecarenone in bulk drug and formulations using quality by design (QBD) approach
ABSTRACT A novel, accurate, precise and economical stability indicating Reverse Phase-High Performance Liquid Chromatography (RP-HPLC) method, was developed and validated for the quantitative determination of ubidecarenone (UDC) in bulk drug, UDC marketed formulation and UDC loaded cubosomes (CBMs) nanocarriers through Response surface methodology (RSM) desi
Braz. J. Pharm. Sci.. Publicado em: 05/03/2018
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6. Potential Bio-Oil Production from Invasive Aquatic Plants by Microscale Pyrolysis Studies
The invasive aquatic plants Eichhornia crassipes (water hyacinth), Eichhornia azurea, and Nymphaea spp. were evaluated as sources of lignocellulosic biomass for the production of bio-oil. These plants have high growth rates that can lead to various environmental problems and the production of large amounts of waste biomass. The materials were characterized i
J. Braz. Chem. Soc.. Publicado em: 2018-01
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7. Some triterpenic compounds in extracts of Cecropia and Bauhinia species for different sampling years
ABSTRACT The aim of this paper is to provide an overview on the chemical composition of triterpenes in widespread used folk medicine species, through the development and validation of eleven compounds using HPLC-UV detection. The compounds were separated using isocratic elution, on a reverse phase column (Kinetex C18, 250 mm × 4.6 mm, 5 µm) with mobile pha
Rev. bras. farmacogn.. Publicado em: 2018-01
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8. Design of a New Molecularly Imprinted Polymer Selective for Hydrochlorothiazide Based on Theoretical Predictions Using Gibbs Free Energy
A molecularly imprinted polymer (MIP) for the diuretic drug hydrochlorothiazide (HCTZ) based on theoretical predictions was developed. Molecular modeling calculations were performed to study the intermolecular interactions in the pre-polymerization mixture and to select a suitable functional monomer and a porogenic solvent for the synthesis of the MIP. To co
J. Braz. Chem. Soc.. Publicado em: 2016-12
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9. Synthesis of 3-(1H-1,2,3-Triazol-1-yl)-2-(arylselanyl)pyridines by Copper-Catalyzed 1,3-Dipolar Cycloaddition of 2-(Arylselanyl)-3-azido-pyridines with Terminal Alkynes
We present here our results in the synthesis of eleven new 3-(1H-1,2,3-triazol-1-yl)-2-(arylselanyl)pyridines by copper-catalyzed azide-alkyne cycloaddition reactions. The reactions were performed in the presence of catalytic amount of copper(II) acetate and sodium ascorbate using a mixture of tetrahydrofuran/water (1:1) as solvent at room temperature in air
J. Braz. Chem. Soc.. Publicado em: 2015-11
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10. Measurement and correlation of isobaric vapor-liquid equilibrium for the binary system of cyclopentane and tetrahydrofuran
Isobaric vapor-liquid equilibrium (VLE) data for the cyclopentane and tetrahydrofuran (THF) system were measured at 101.3 kPa by using an equilibrium still. Thermodynamic consistency of the experimental data was confirmed by means of the Herington method. The experimental data were correlated and calculated by the Margules, Van Laar and Wilson activity-coeff
Braz. J. Chem. Eng.. Publicado em: 2014-09
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11. Influência de diferentes solventes utilizados na deposição de filme de poli(9-vinilcarbazol) em dispositivos OLEDs
This work studies the influence of the film deposition process on light emission performance and on threshold voltage of OLEDs, with architecture glass/ITO/PEDOT:PSS/PVK/Alq3/Al. The commercial PVK was dissolved in different solvents such as: chloroform, tetrahydrofuran, 1,2,4-trichlorobenzene and trimethylpentane. OLEDs were characterized by current-voltage
Quím. Nova. Publicado em: 2014
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12. Chemical cleaning agents and bonding to glass-fiber posts
The influence of chemical cleaning agents on the bond strength between resin cement and glass-fiber posts was investigated. The treatments included 10% hydrofluoric acid, 35% phosphoric acid, 50% hydrogen peroxide, acetone, dichloromethane, ethanol, isopropanol, and tetrahydrofuran. Flat glass-fiber epoxy substrates were exposed to the cleaners for 60 s. Res
Braz. oral res.. Publicado em: 2013-02