Search results for "ACID"

showing 10 items of 13107 documents

Reaction of 2-acetyltetralone with some esters of benzoic acid

1986

In order to investigate the pharmacological screening of a number of pyran-4-ones their synthesis by cyclization with sulphuric acid of the corresponding 1,3,5-triketones has been carried out with high yields. In the course of preparation of the latter the reaction of 2-acetyltetralone with some esters of benzoic acid derivatives has been studied and in particular, for a number of them, an interesting nucleophilic substitution of a chlorine atom with an alkoxy group on a benzenic nucleus has been evidenced.

inorganic chemicalschemistry.chemical_compoundBicyclic moleculechemistryOrganic ChemistryChlorine atomAlkoxy groupNucleophilic substitutionTriketoneOrganic chemistryAcid hydrolysisSulfuric acidBenzoic acidJournal of Heterocyclic Chemistry
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ChemInform Abstract: Reaction of 2-Acetyltetralone with Some Esters of Benzoic Acid.

1987

In order to investigate the pharmacological screening of a number of pyran-4-ones their synthesis by cyclization with sulphuric acid of the corresponding 1,3,5-triketones has been carried out with high yields. In the course of preparation of the latter the reaction of 2-acetyltetralone with some esters of benzoic acid derivatives has been studied and in particular, for a number of them, an interesting nucleophilic substitution of a chlorine atom with an alkoxy group on a benzenic nucleus has been evidenced.

inorganic chemicalschemistry.chemical_compoundChemistryChlorine atomAlkoxy groupNucleophilic substitutionOrder (group theory)General MedicineMedicinal chemistryBenzoic acidChemInform
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Crystal structure of a 1:1 salt of 4-amino­benzoic acid (vitamin B10) with pyrazinoic acid

2018

The paper reports the crystal structure of novel salt of 4-amino­benzoic acid (Vitamin B10) with pyrazinoic acid.

inorganic chemicalscrystal structure4-amino­benzoic acidmelting pointStackingchemical and pharmacologic phenomena02 engineering and technologyCrystal structure010402 general chemistry01 natural sciencesCocrystalResearch Communicationslcsh:ChemistryCrystalchemistry.chemical_compoundPyrazinoic acidpyrazinoic acid4-Aminobenzoic acidsaltGeneral Materials ScienceBenzoic acidHydrogen bondChemistryorganic chemicalshemic and immune systemsGeneral Chemistry021001 nanoscience & nanotechnologyCondensed Matter Physicshydrogen bonding0104 chemical sciencesCrystallography4-aminobenzoic acidlcsh:QD1-9990210 nano-technologyActa Crystallographica Section E: Crystallographic Communications
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Crystal structure ofN-(tert-butoxycarbonyl)glycyl-(Z)-β-bromodehydroalanine methyl ester [Boc–Gly–(β-Br)(Z)ΔAla–OMe]

2014

In a de­hydro­amino acid with a C=C bond between the α- and β-C atoms, the amino acid residues are linked trans to each other and there are no strong intra­molecular hydrogen bonds. The torsion angles indicate a non-helical conformation of the mol­ecule.

inorganic chemicalscrystal structureStereochemistryeducationCrystal structurebehavioral disciplines and activitiesResearch CommunicationsSteric repulsionlcsh:Chemistrychemistry.chemical_compoundde­hydro­amino acidβ-bromo­dehydro­alaninedehydroamino acidnon-helical conformationGeneral Materials Science[beta]-bromo­dehydro­alanineAmino acid residuehealth care economics and organizationsQuantitative Biology::BiomoleculesDipeptideChemistryHydrogen bondGeneral Chemistryhydrogen bondingCondensed Matter Physicshumanitieslcsh:QD1-999β-bromodehydroalanineAlanine methyl esterActa Crystallographica Section E Structure Reports Online
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Study of the role of sulfur functionalities in humic acids for uranium(VI) complexation

2009

Humic substances influence the speciation and migration behavior of toxic and radiotoxic metal ions, such as actinides, in the environment. Depending on their origin, humic substances contain different amounts of sulfur ranging from 0.1 to 3.6% and 0.5 to 1.43% in soil and aquatic humic substances, respectively [1]. Reduced, intermediately oxidized and highly oxidized sulfur functionalities occur in humic substances [1]. Although sulfur functionalities occur in small concentrations, they can play an important role in the complexation of selected metal ions. Knowledge about the impact of sulfur functionalities on the metal ion complexation by humic substances and their significance compared …

inorganic chemicalsfs-TRLFScomplexationInorganic chemistryTRLFSchemistry.chemical_elementHumic substancesOxygencomplex mixturesFluorescence spectroscopysulfur functionalitiesfunctional groupsX-ray photoelectron spectroscopyXPSHumic acidPhysical and Theoretical Chemistrychemistry.chemical_classificationLigandUraniumSulfurhumic acidshumic acid model substanceschemistryHumic aciduranium(VI)sulfurThiol
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Friedel-Crafts catalytic alkylations using rare earth-based mineral supports

1998

Abstract Rare earth halides supported on mineral supports (K10 montmorillonite and silica) were investigated as catalysts for Friedel-Crafts alkylations. This project concerns the replacement of the widely used Lewis acid AlCl3 in Friedel-Crafts reactions by environmentally friendly catalysts in that they circumvent the production of aluminum waste. The catalytic activity of these heterogeneous catalysts was established in a series of alkylations of aromatic compounds.

inorganic chemicalsintegumentary systemHalideGeneral ChemistryAlkylationHeterogeneous catalysisEnvironmentally friendlyCatalysischemistry.chemical_compoundMontmorillonitechemistryOrganic chemistryLewis acids and basesFriedel–Crafts reactionComptes Rendus de l'Académie des Sciences - Series IIC - Chemistry
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Lignin-based activated carbon-supported metal oxide catalysts in lactic acid production from glucose

2021

In this study, heterogeneous biomass-based activated carbon-supported metal oxide catalysts were prepared and tested for lactic acid production from glucose in aqueous solution. Activated carbons were produced from hydrolysis lignin by chemical (ZnCl2) or steam activation and modified with a nitric acid treatment and Sn, Al, and Cr chlorides to obtain carbon-based metal oxide catalysts. The modification of the carbon support by nitric acid treatment together with Sn and Al oxides led to an increase in lactic acid yield. The highest lactic acid yield (42%) was obtained after 20 minutes at 180 °C with the Sn/Al (5/2.5 wt.%) catalyst on steam-activated carbon treated by nitric acid. Reusabilit…

inorganic chemicalsmaitohappobiomasskemialliset reaktiotheterogeneous catalystlactic acidfood and beveragesmetal oxidecomplex mixturesglukoosikatalyytitkatalyysiaktiivihiilioksiditkemian tekniikkaactivated carbonbiomassa (teollisuus)aqueous solutionmuuntaminen
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Effects of magnesium chloride on the contractile response of uterus to several agonists in Ca-free solution

1987

Abstract The effects of MgCl2 on the oestrogen-dominated rat uterus have been examined. Tissues were preincubated in a Ca2+- and Mg2+-free medium containing 3 mM EDTA. Most experiments were subsequently performed in a similar medium containing either no EDTA or EDTA (1 mM). When MgCl2 was added cumulatively (1–32 mM) no contractile responses were obtained in Ca,Mg-free medium or in Ca,Mg-free high K+ solution. When 2 mM CaCl2 as added, a sustained contraction was obtained. Subsequent addition of cumulative concentrations of MgCl2 caused concentration-dependent relaxation. Oxytocin, 2 μM, produced a small and sustained contraction in a Ca,Mg-free medium. Addition of MgCl2, 2 mM, increased th…

inorganic chemicalsmedicine.medical_specialtyContraction (grammar)PotassiumMagnesium ChloridePharmaceutical Sciencechemistry.chemical_elementIn Vitro TechniquesCalciumOxytocinPotassium ChlorideUterine contractionUterine ContractionInternal medicinemedicineAnimalsMagnesiumVanadateEdetic AcidPharmacologyMagnesiumRats Inbred StrainsVanadiumRatsEndocrinologychemistryOxytocinCalciumFemaleVanadatesmedicine.symptommedicine.drugMuscle contractionJournal of Pharmacy and Pharmacology
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The CdCl2 effects on synthetic DNAs encaged in the nanodomains of a cationic water-in-oil microemulsion

2011

The present work is dedicated to the study of the interactions of CdCl(2) with the synthetic polynucleotides polyAT and polyGC confined in the nanoscopic aqueous compartment of the water-in-oil microemulsion CTAB/pentanol/hexane/water, with the goal to mimic in vitro the situation met by the nucleic acids in vivo. In biological structures, in fact, very long strings of nucleic acids are segregated into very small compartments having a radius exceedingly smaller than the length of the encapsulated macromolecule. For comparison, the behaviour of polyGC was also studied in aqueous solutions of matched composition. The conformational and thermal stabilities of both polynucleotides enclosed in t…

inorganic chemicalsnanodomaincadmiumPolynucleotideswater-in-oil microemulsion; cadmium; model polynucleotidesGeneral Physics and AstronomyDissociation (chemistry)model polynucleotideschemistry.chemical_compoundCadmium ChlorideHexanesOrganic chemistryMicroemulsionPhysical and Theoretical ChemistryAqueous solutionconformational transitionCetrimoniumChemistryCationic polymerizationWaterDNAHexaneUV and CD spectroscopiesreverse micelleChemical engineeringwater-in-oil microemulsionPolynucleotideCetrimonium CompoundsNucleic acidCationic w/o microemulsionEmulsionssynthetic polynucleotideOilsMacromolecule
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Water compatible gold(III)-catalysed synthesis of unsymmetrical ethers from alcohols.

2008

An efficient and broad-scoped method for the preparation of unsymmetrical ethers from alcohols catalysed by the simplest and least expensive gold catalyst, NaAuCl 4 , is described for the first time. The procedure enables the etherification of benzylic and tertiary alcohols with moderate to good yields under mild conditions with low catalyst loading. Symmetrical ethers, the usual side products in the etherification of alcohols, were not detected in this case. The formation of the racemic ether from a chiral benzyl alcohol suggests the intermediacy of a carbocation, which has not previously been postulated for gold-catalysed reactions involving alcohols.

inorganic chemicalsorganic chemicalsOrganic ChemistryEtherHomogeneous catalysisGeneral ChemistryCarbocationCatalysisCatalysischemistry.chemical_compoundGold iiichemistryBenzyl alcoholOrganic chemistryheterocyclic compoundsLewis acids and basesTertiary alcoholsChemistry (Weinheim an der Bergstrasse, Germany)
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