Enthalpies of solution of naphthalene, N,N-dimethyl-1-naphthylamine, and 1,8-bis(dimethylamino)naphthalene in 16 organic solvents

1992 ◽  
Vol 70 (6) ◽  
pp. 1586-1589 ◽  
Author(s):  
Daniel Figeys ◽  
Maegorzata Koschmidder ◽  
Robert L. Benoit
Keyword(s):  
Carbon Tetrachloride ◽  
Ethyl Acetate ◽  
Dimethyl Sulfoxide ◽  
Organic Solvents ◽  
Enthalpies Of Solution ◽  
Proton Sponge ◽  
Solvent Interactions ◽  
Linear Relationships

The enthalpies of solution of naphthalene, N,N-dimethyl-1-naphthylamine, and 1,8-bis(dimethylamino)naphthalene (proton sponge) were determined at 298.15 K in 16 organic solvents (n-hexane, cyclohexane, carbon tetrachloride, chloroform, 1,2-dichloroethane, benzene, chlorobenzene, dimethyl sulfoxide, N,N-dimethylformamide, ethyl acetate, 1,4-dioxane, anisole, nitrobenzene, benzonitrile, methanol, ethanol). Additional determinations were made with benzene. Useful linear relationships are observed between the molar enthalpies of solution of the four compounds in the solvents. The molar enthalpies of solution were correlated with the solvatochromic parameter of the solvents. The presence of N(CH3)2 groups on naphthalene does not significantly contribute to the solute–solvent interactions.

Dimethylgermanium Dinitrate

1971 ◽  
Vol 49 (2) ◽  
pp. 202-206 ◽  
Author(s):  
D. Potts ◽  
A. Walker
Keyword(s):  
Carbon Tetrachloride ◽  
Ethyl Acetate ◽  
Dimethyl Sulfoxide ◽  
Infrared Spectra ◽  
Vibrational Spectra ◽  
Conductivity Measurements ◽  
Alkyl Nitrates ◽  
Methyl Cyanide ◽  
Nitrogen Pentoxide ◽  
Group Iva

Dimethylgermanium dinitrate has been prepared by the reaction of dimethylgermanium dichloride and nitrogen pentoxide in carbon tetrachloride. The properties of this compound have been investigated and compared with those of other known Group IVA alkyl nitrates. The vibrational spectra show that the nitrato groups are covalently bound to the germanium in a unidentate manner. Ultraviolet spectra and conductivity measurements indicate that the compound behaves as a 1:2 electrolyte in water and dimethyl sulfoxide but is a non-electrolyte in methyl cyanide, nitromethane, and ethyl acetate. The complexes Me2Ge(NO3)2•py and Me2Ge(NO3)2•2,2′dipy have been prepared and the infrared spectra of these compounds indicate considerable weakening of the germanium-nitrato bonds.

Enthalpies of interaction of ketones with organic solvents

1985 ◽  
Vol 63 (2) ◽  
pp. 336-341 ◽  
Author(s):  
W. Kirk Stephenson ◽  
Richard Fuchs
Keyword(s):  
Organic Solvents ◽  
Bond Formation ◽  
Butyl Alcohol ◽  
Enthalpies Of Solution ◽  
Butyl Ether ◽  
Hydrogen Bond Formation ◽  
Linear Relationships ◽  
Benzene Toluene ◽  
Polar Interactions ◽  
Alcohol Solvents

Enthalpies of solution (ΔHS) of a series of ketones (acetone, 2-butanone, 2-heptanone, 2-nonanone, 5-nonanone, 2,2,4,4-tetramethyl-3-pentanone, cyclohexanone) and alkane model compounds (n-heptane, n-nonane, 2,2,4,4-tetramethylpentane, cyclohexane) have been determined in 17 organic solvents (n-heptane, cyclohexane, CCl4, α,α,α,-trifluorotoluene, 1,2-dichloroethane, triethylamine, butyl ether, ethyl acetate, DMF, DMSO, benzene, toluene, mesitylene, 1-octanol, methanol, t-butyl alcohol, 2,2,2-trifluoroethanol), and combined with heats of vaporization to give enthalpies of transfer from vapor to solvent (ΔH(v → S)). These values have been used to evaluate ketone–solvent polar interactions (ΔΔH(v → S) = ΔH(v → S)(ketone) − ΔH(v → S)(alkane)). The linear relationships between ΔΔH(v → S) and solvent dipolarity-polarizability (Taft-Kamlet π* parameters) are derived. Based on the deviations from these correlations, ketone–CF3CH2OH enthalpies of hydrogen bond formation have been evaluated. The other alcohol solvents show no evidence of exothermic H-bond formation with ketones.

Heats of Solution of Some Sodium and Potassium Salts in Water and in Water-Methanol Mixtures

1992 ◽  
Vol 57 (11) ◽  
pp. 2227-2234 ◽  
Author(s):  
Ján Benko ◽  
Oľga Vollárová
Keyword(s):  
Transfer Functions ◽  
Enthalpies Of Solution ◽  
Potassium Salts ◽  
Solvent Interactions ◽  
Heats Of Solution ◽  
Solvent Molecules ◽  
Sodium And Potassium

The enthalpies of solution ∆Hs0 were determined for NaSCN, KSCN, NaBrO3, KBrO3, NaClO3, KClO3, NaIO4, KMnO4, KNO2 and NaNO2 in water-methanol mixtures. The transfer functions ∆Ht0 of the salts and anions were calculated based on the extrathermodynamic TPTB assumption. The ∆Ht0 values of the anion obtained from the sodium and potassium salts were compared. The differences observed, particularly at higher concentrations of the cosolvent, are discussed with respect to the interactions between the solvent molecules and the solute-solvent interactions.

HSCCC Separation of Three Main Compounds from the Crude Extract of Dracocephalum Tanguticum by Using Dimethyl Sulfoxide as Cosolvent

2020 ◽  
Author(s):  
Xue Yang ◽  
Yongling Liu ◽  
Tao Chen ◽  
Nana Wang ◽  
Hongmei Li ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Ethyl Acetate ◽  
Dimethyl Sulfoxide ◽  
Efficient Method ◽  
Crude Extract ◽  
High Speed ◽  
Glacial Acetic Acid ◽  
Butyl Alcohol ◽  
Preparative Hplc ◽  
Counter Current

Abstract Separation of natural compounds directly from the crude extract is a challenging work for traditional column chromatography. In the present study, an efficient method for separation of three main compounds from the crude extract of Dracocephalum tanguticum has been successfully established by high-speed counter-current chromatography (HSCCC). The crude extract was directly introduced into HSCCC by using dimethyl sulfoxide as cosolvent. Ethyl acetate/n-butyl alcohol/0.3% glacial acetic acid (4: 1: 5, v/v) system was used and three target compounds with purity higher than 80% were obtained. Preparative HPLC was used for further purification and three target compounds with purity higher than 98% were obtained. The compounds were identified as chlorogenic acid, pedaliin and pedaliin-6″-acetate.

scholarly journals Toxicity of Thevetia peruviana (Pers) Schum. Extract to Adults of Callosobruchus maculatus F. (Coleoptera: Bruchidae)

1970 ◽  
pp. 105-109 ◽  
Author(s):  
JU Mollah ◽  
W Islam
Keyword(s):  
Ethyl Acetate ◽  
Key Words ◽  
Organic Solvents ◽  
Callosobruchus Maculatus ◽  
Root Extract ◽  
Thevetia Peruviana

Leaf, stem and roots of Thevetia peruviana (Pers) Schum. were extracted in four organic solvents; petroleum spirit, ethyl acetate, acetone and methanol and tested against the adults of Callosobruchus maculatus F. All the tested extracts effectively produced mortality of C. maculatus and their toxicity was in order of solvents: petroleum spirit>ethyl acetate>acetone>methanol. Root extract was the most toxic to C. maculatus. Females were more tolerant than males. Key words: Extract, mortality, solvent, Thevetia peruviana, Callosobruchus maculatus. DOI = 10.3329/jard.v5i1.1466 J Agric Rural Dev 5(1&2), 105-109, June 2007

A QSPR study on the solvent-induced frequency shifts of acetone and dimethyl sulfoxide in organic solvents

2016 ◽  
Vol 162 ◽  
pp. 109-114 ◽  
Author(s):  
Yu Heng Ou ◽  
Chia Ming Chang ◽  
Ying Shao Chen
Keyword(s):  
Dimethyl Sulfoxide ◽  
Organic Solvents ◽  
Frequency Shifts ◽  
Qspr Study

scholarly journals A Polyphenol-Rich Fraction from Eugenia uniflora Exhibits Antioxidant and Hepatoprotective Activities In Vivo

2020 ◽  
Vol 13 (5) ◽  
pp. 84
Author(s):  
Mansour Sobeh ◽  
Marwa S. Hamza ◽  
Mohamed L. Ashour ◽  
Mona Elkhatieb ◽  
Mohamed A El Raey ◽  
...  
Keyword(s):  
Carbon Tetrachloride ◽  
Liver Injury ◽  
Ethyl Acetate ◽  
Acute Liver Injury ◽  
Antioxidant Activities ◽  
Biological Effects ◽  
Ethyl Acetate Fraction ◽  
Eugenia Uniflora ◽  
Quercetin Derivatives

Leaves from Eugenia uniflora, the red Brazilian cherry, have a high content of flavonoids that possess several biological effects such as anti-inflammatory, antioxidant, and antidiabetic activities. However, their influence on carbon tetrachloride (CCl4)-induced acute liver injury in rats has not been investigated. In the current study, a bioguided fractionation assay revealed that the ethyl acetate fraction (EAF) of Eugenia uniflora is the safest and most active fraction. LC-MS analysis of the ethyl acetate fraction revealed 22 secondary metabolites, mainly myricetin and quercetin derivatives. EAF did not show toxicity up to 2000 mg/kg, and exhibited antioxidant activities in vitro in DPPH assay with IC50 of 3.35 µg/mL. Additionally, EAF exhibited substantial antioxidant activities in vivo by counteracting the oxidative damage of the prooxidant juglone [80 µM] in Caenorhabditis elegans model organism and increased its survival rate in a dose-dependent fashion through the DAF-16/Foxo pathway. Furthermore, the hepatoprotective activity of EAF (200 mg/kg against carbon tetrachloride (CCl4) intoxicated male Wistar rats was assessed. EAF significantly inhibited CCl4-induced elevation of alanine aminotransferase (ALT), aspartate transaminase (AST), total bilirubin (TB), total cholesterol (TC), and triglycerides (TG), in the blood serum and prevented lipid peroxidation and restored superoxide dismutase (SOD) activity and glutathione (GSH) content in liver tissues. The observed hepatoprotective effects of EAF, which were supported by histopathological observations as pretreatment with EAF, effectively attenuated the CCl4-induced histopathological changes. In conclusion, EAF of Eugenia uniflora leaves has substantial hepatoprotective activities against CCl4 induced acute liver injury in rats due to its antioxidant activity.

N,N-Dialkyl-N′-Chlorosulfonyl Chloroformamidines in Heterocyclic Synthesis. Part XIII. Cleavage and Rearrangement Reactions of Pyrazolo[1,5-b][1,2,4,6]thiatriazine 1,1-Dioxides

2016 ◽  
Vol 69 (1) ◽  
pp. 61 ◽  
Author(s):  
Rebecca E. Norman ◽  
Michael V. Perkins ◽  
Andris J. Liepa ◽  
Craig L. Francis
Keyword(s):  
Ethyl Acetate ◽  
Dimethyl Sulfoxide ◽  
Trifluoroacetic Acid ◽  
Sulfonic Acid ◽  
Trifluoroacetic Anhydride ◽  
Ring Cleavage ◽  
Thermal Rearrangement ◽  
Heterocyclic Synthesis ◽  
Similar Treatment ◽  
Catalytic Hydrogenolysis

Treatment of pyrazolo[1,5-b][1,2,4,6]thiatriazines 1 with the Vilsmeier–Haack reagent afforded pyrazolo[1,5-a][1,3,5]triazines 5. Reaction of compounds 1 with trifluoroacetic anhydride, dimethyl sulfoxide, and triethylamine afforded 5-dimethylsulfanylidene derivatives 8. The guanidino-pyrazole-sulfonic acid 9 was produced from treatment of compounds 1 with trifluoroacetic acid under anhydrous conditions. Similar treatment in the presence of water afforded the desulfonated pyrazolo-guanidine 6. Reactions of 6 with one-carbon electrophiles provided various 4-substituted pyrazolo[1,5-a][1,3,5]triazines 5. Attempted catalytic hydrogenolysis of N7-benzyl pyrazolo[1,5-b][1,2,4,6]thiatriazines 2 in alcohols led to sulfamates 12 from thiatriazine ring cleavage. Ethyl acetate or tert-butanol as solvent allowed successful debenzylation to provide compounds 1. Aminolysis of compounds 2 gave sulfamides 13. Thermal rearrangement of compounds 2 afforded 6-benzyl-pyrazolo[3,4-e][1,2,4]thiadiazines 14.

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