Effect of solvent on the kinetics of arylsulfonylation of N-alkylated anilines in a water-propan-2-ol system

The effect of the composition of a water-propan-2-ol solvent on the kinetics of arylsulfonylation of N-ethyl-, N-isopropyl-, and N-butylanilines with 3-nitrobenzenesulfonyl chloride at 298 K was studied. The reaction rate constant increases monotonically with an increase in the water fraction in the solvent from 5 to 30 wt.%. The apparent activation parameters of the reaction of N-butylaniline with 3-nitrobenzenesulfonyl chloride were calculated. No considerable changes in the activation parameters of the reaction were observed on going from pure propan-2-ol to a 10% aqueous solution, which indicates that the mechanism remains unchanged upon solvent change. Propan-2-ol with a water content of 5–30 wt.% can be used in the synthesis of arylsulfonylation products of the amines under study in 98–99% yield. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 937–939, June, 2006.     

Solvatochromic parameters for binary mixtures of an ionic liquid with various protic molecular solvents

Abstract  Solvatochromic parameters (E _T ^N, normalized polarity parameter; π*, dipolarity/polarizability; β, hydrogen-bond acceptor basicity; α, hydrogen-bond donor acidity) have been determined for binary mixtures of propan-2-ol, propan-1-ol, ethanol, methanol and water with recently synthesized ionic liquid (IL; 2-hydroxyethylammonium formate) at 25 °C. In all solutions except aqueous solution, E _T ^N values of the media increase abruptly with the ILs mole fraction and then increase gradually to the value of pure IL. A synergistic behavior is observed for the α parameter in all solutions. The behavior of π* and β are nearly ideal for all solutions except for solutions of methanol with the IL. The applicability of nearly ideal combined binary solvent/Redlich–Kister equation was proved for the correlation of various solvatochromic parameters with solvent composition. The correlation between the calculated and the experimental values of various parameters was in accordance with this model. Solute–solvent and solvent–solvent interactions were applied to interpret the results. Graphical Abstract  Predicted values of solvatochromic parameters (SP) (E _T ^N, normalized polarity parameter; π*, dipolarity/polarizability; β, hydrogen-bond acceptor basicity; α, hydrogen-bond donor acidity) from the correlation equations versus its experimental values for binary mixtures of 2-hydroxyethylammonium formate with water, methanol, ethanol, propan-1-ol and propan-2-ol.      

Acid–base interactions and swelling of cellulose fibers in organic liquids

Drago’s acid–base approach was used to quantify the hydrogen bonding interactions in solvent swelling of cellulose fibers. The fiber swelling was correlated with acid–base, dispersive interactions and solvent molar volume. The acid–base interaction potentials of solvents were expressed in terms of their electron pair donor and acceptor numbers. The acid–base interaction terms of cellulosic materials were determined by using: (1) Flory–Huggins; (2) multiple regression models. We have used the swelling data of Mantanis and coworkers, which were based on the equilibrium liquid holding capacities of various compressed fibers in water and series of organic solvents. According to our interpretations, acid–base interactions and molar volume parameters were the major contributors to the overall solubility parameter. Acid–base interaction terms were balanced in alpha-cellulose sample. However spruce wood and sulfite pulp samples were more acidic than basic and therefore swollen better in organic basic solvents. For a good swelling behavior solvent must have high electron pair donor number/acceptor number ratio and high electron pair donor number–acceptor number difference.     

Solvatochromic parameters for binary mixtures of an ionic liquid with various protic molecular solvents

Abstract  

Solvatochromic parameters (E _T ^N, normalized polarity parameter; π*, dipolarity/polarizability; β, hydrogen-bond acceptor basicity; α, hydrogen-bond donor acidity) have been determined for binary mixtures of propan-2-ol, propan-1-ol, ethanol, methanol and water with recently synthesized ionic liquid (IL; 2-hydroxyethylammonium formate) at 25 °C. In all solutions except aqueous solution, E _T ^N values of the media increase abruptly with the ILs mole fraction and then increase gradually to the value of pure IL. A synergistic behavior is observed for the α parameter in all solutions. The behavior of π* and β are nearly ideal for all solutions except for solutions of methanol with the IL. The applicability of nearly ideal combined binary solvent/Redlich–Kister equation was proved for the correlation of various solvatochromic parameters with solvent composition. The correlation between the calculated and the experimental values of various parameters was in accordance with this model. Solute–solvent and solvent–solvent interactions were applied to interpret the results.     

Effect of a thin spreading solvent film on the efficiency of the hexadecan-1-ol monolayer deposited for water evaporation retardation

The influence of a thin spreading solvent film (ethanol, diethyl ether, and three fractions of petroleum ether boiling at 30–60 °C, 60–90 °C, and 90–120 °C) on the properties of hexadecan-1-ol (C₁₆H₃₃OH) monolayers at the air—water interface was studied. The specific evaporation resistance and the surface pressure were determined to describe the spreading behavior of the C₁₆H₃₃OH monolayers. The physical properties of the solvents and the images obtained in an atomic force microscope were examined. The time of establishing the equilibrium spreading surface pressure of monolayers can be reduced using a more volatile solvent with a lower boiling point and a lower relative density. The influence of the monolayer nature on water evaporation corresponds to the order of changing the solvent spreading rate: petroleum ether (30–60 °C) > diethyl ether > ethanol > petroleum ether (60–90 °C) > petroleum ether (90–120 °C). The monolayers formed upon petroleum ether (30–60 °C) spreading form a film with a less deficient and relatively planar surface. When ethanol is used as a spreading solvent, water evaporation is accelerated rather than retarded, while petroleum ether (30–60 °C) is more appropriate for this purpose.     

Reactivity of primary and secondary alcohols in nucleophilic addition to a triple bond: the vinylation of butane-1,3-diol

Acetylene adds to butane-1,3-diol in the presence of KOH to give, along with the corresponding divinyl ether and 2,4-dimethyl-1,3-dioxane, 4-vinyloxybutan-2-ol and its structural isomer 3-vinyloxybutan-1-ol, the ratio between the latter two products, (5–8)∶1, depending on the reaction conditions. Translated fromIzvestiya Akademii Nauk, Seryia Khimicheskaya, No. 12, pp. 2372–2374, December, 1999.     

Synthesis and properties of aminomethyloxy derivatives of (1-Propylsulfanyl)pentane

New 2-aminomethyloxy derivatives of 1-(propylsulfanyl)pentane were prepared by condensation of 1-(propylsulfanyl)pentan-2-ol with formaldehyde and secondary amines. The starting 1-(propylsulfanyl)pentan-2–ol was synthesized by the reaction of 1–propanethiol with 1–bromopentan–2–ol. The structures of the products were proved by elemental analysis, IR and ¹H NMR spectroscopy, and mass spectrometry. The compounds were tested as antimicrobial additives to lubricating oils and as antiseptics against bacteria and fungi.     

Conformational Analysis,Infrared, and Fluorescence Spectra of 1-Phenyl-1,2-propandione 1-oxime and Related Tautomers: Experimental and Theoretical Study

Summary. Conformational analysis and frequency calculation were achieved for 1-phenyl-1,2-propandione 1-oxime and its four tautomers: 1-nitroso-1-phenyl-1-propen-2-ol, 1-nitroso-1-phenyl-2-propanone, 2-hydroxy-1-phenyl-propenone oxime, and 3-nitroso-3-phenyl-propen-2-ol. Calculations were carried out at the Hartree–Fock (HF), Density Functional Theory (B3LYP), and the second-order M?ller–Plesset perturbation (MP2) levels of theory using 6-31G^* and 6-311G^** basis sets. Five conformers with no imaginary vibrational frequency were obtained by free rotations around three single bonds of 1-phenyl-1,2-propandione-1-oxime: Ph–C(NOH)C(O)CH₃, PhC(NOH)–C(O)CH₃, and PhC(N–OH)C(O)CH₃. Similarly, eight structures with no imaginary vibrational frequency were encountered upon rotations around three single bonds of 1-nitroso-1-phenyl-1-propen-2-ol: Ph–C(NO)C(OH)CH₃, PhC(N–O)C(OH)CH₃, and PhC(NO)C(–OH)CH₃. In the same manner, six minima were found through rotations around three single bonds of 1-nitroso-1-phenyl-2-propanone: Ph–CH(NO)C(O)CH₃, PhCH(–NO)C(O)CH₃, and PhCH(NO)–C(O)CH₃. Also, two minima were found through rotations around four single bonds of 2-hydroxy-1-phenyl-propenone oxime: Ph–C(NOH)C(OH)CH₂, PhC(N–OH)C(OH)CH₂, PhC(NOH)–C(OH)CH₂, and Ph-C(NOH)C(–OH)CH₂. Finally, two minima were found through rotations around four single bonds of 3-nitroso-3-phenyl-propen-2-ol: Ph–CH(NO)C(OH)CH₂, PhCH(–NO)C(OH)CH₂, PhCH(NO)–C(OH)CH₂, and PhCH(NO)C(–OH)CH₂. Interconversions within the above sets of conformers were probed through scanning (one and/or two dimensional), and/or QST3 techniques. The order of the stability of global minima encountered was: 1,2-propandione-1-oxime > 1-nitroso-1-phenyl-2-propanone > 1-nitroso-1-phenyl-1-propen-2-ol > 2-hydroxy-1-phenyl-propenone oxime > 3-nitroso-3-phenyl-propen-2-ol. Hydrogen bonding appears significant in tautomers of 1-nitroso-1-phenyl-1-propen-2-ol and 2-hydroxy-1-phenyl-propenone oxime. The CIS simulated λ_max for the first excited singlet state (S₁) of 1-phenyl-1,2-propandione 1-oxime is 300.4 nm, which was comparable to its experimental λ_max of 312.0 nm. The calculated IR spectra of 1-phenyl-1,2-propandione 1-oxime and its tautomers were compared to the experimental spectra.     

Conformational Analysis, Infrared, and Fluorescence Spectra of 1-Phenyl-1,2-propandione 1-oxime and Related Tautomers: Experimental and Theoretical Study

Conformational analysis and frequency calculation were achieved for 1-phenyl-1,2-propandione 1-oxime and its four tautomers: 1-nitroso-1-phenyl-1-propen-2-ol, 1-nitroso-1-phenyl-2-propanone, 2-hydroxy-1-phenyl-propenone oxime, and 3-nitroso-3-phenyl-propen-2-ol. Calculations were carried out at the Hartree–Fock (HF), Density Functional Theory (B3LYP), and the second-order M?ller–Plesset perturbation (MP2) levels of theory using 6-31G^* and 6-311G^** basis sets. Five conformers with no imaginary vibrational frequency were obtained by free rotations around three single bonds of 1-phenyl-1,2-propandione-1-oxime: Ph–C(NOH)C(O)CH₃, PhC(NOH)–C(O)CH₃, and PhC(N–OH)C(O)CH₃. Similarly, eight structures with no imaginary vibrational frequency were encountered upon rotations around three single bonds of 1-nitroso-1-phenyl-1-propen-2-ol: Ph–C(NO)C(OH)CH₃, PhC(N–O)C(OH)CH₃, and PhC(NO)C(–OH)CH₃. In the same manner, six minima were found through rotations around three single bonds of 1-nitroso-1-phenyl-2-propanone: Ph–CH(NO)C(O)CH₃, PhCH(–NO)C(O)CH₃, and PhCH(NO)–C(O)CH₃. Also, two minima were found through rotations around four single bonds of 2-hydroxy-1-phenyl-propenone oxime: Ph–C(NOH)C(OH)CH₂, PhC(N–OH)C(OH)CH₂, PhC(NOH)–C(OH)CH₂, and Ph-C(NOH)C(–OH)CH₂. Finally, two minima were found through rotations around four single bonds of 3-nitroso-3-phenyl-propen-2-ol: Ph–CH(NO)C(OH)CH₂, PhCH(–NO)C(OH)CH₂, PhCH(NO)–C(OH)CH₂, and PhCH(NO)C(–OH)CH₂. Interconversions within the above sets of conformers were probed through scanning (one and/or two dimensional), and/or QST3 techniques. The order of the stability of global minima encountered was: 1,2-propandione-1-oxime > 1-nitroso-1-phenyl-2-propanone > 1-nitroso-1-phenyl-1-propen-2-ol > 2-hydroxy-1-phenyl-propenone oxime > 3-nitroso-3-phenyl-propen-2-ol. Hydrogen bonding appears significant in tautomers of 1-nitroso-1-phenyl-1-propen-2-ol and 2-hydroxy-1-phenyl-propenone oxime. The CIS simulated λ_max for the first excited singlet state (S₁) of 1-phenyl-1,2-propandione 1-oxime is 300.4 nm, which was comparable to its experimental λ_max of 312.0 nm. The calculated IR spectra of 1-phenyl-1,2-propandione 1-oxime and its tautomers were compared to the experimental spectra.     

Study of alkaloids of the Siberian and Altai flora 13. Synthesis of alkynyllappaconitines

The Sonogashira coupling of 5′-iodolappaconitine with prop-2-yn-1-ol, 2-methylbut-3-yn-2-ol, phenylacetylene, and 5-ethynylpyrimidine gave new lappaconitine derivatives containing an alkynyl fragment. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 344–348, February, 2007.     

Oxidation of alcohols by chlorine dioxide in organic solvents

The kinetics of oxidation of a series of alcohols (propan-2-ol, 2-methylpropan-1-ol, butan-1-ol, butan-2-ol, 3-methylpentan-1-ol, heptan-4-ol, decan-2-ol, cyclohexanol, borneol) by chlorine dioxide in organic solvents was studied using spectrophotometry. The reaction is described by the second-order rate equation w = k[ROH][ClO₂]. The rate constants were measured in the range of 10–60 °C, and the activation parameters of the processes were calculated. The products were identified, and the yields were determined.     

Synthesis and properties of <Emphasis Type="Italic">N</Emphasis>-(2-ethoxyethyl) piperidine derivatives of anabasine

The synthesis and pharmacological activity of ethers of 1-(2-ethoxyethyl)-4-[3-anabasin-1-yl-1-prop-1-ynyl]piperidin-4-ol were described. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 360–363, July–August, 2007.     

Experimental designs dedicated to the evaluation of a membrane extraction method: membrane-assisted solvent extraction for compounds having different polarities by means of gas chromatography–mass detection

Membrane-assisted solvent extraction was applied for the determination of different classes of compounds in water, having K _o/w (octanol–water partition coefficient) values between 10¹ (aniline) and 10⁸ (methyl stearate), by means of experimental designs. Four solvents were investigated—propan-2-ol, ethyl acetate, diisopropyl ether and cyclohexane—as well as extraction time, temperature, salt impact, pH and methanol addition. The best choice was diisopropyl ether, 50 °C, 30 min and an addition of 3 g of sodium chloride at pH 2 for polar compounds. The relative standard deviation (n = 3) was found in the range from 5 to 17%. Recoveries ranged between 34 and 100%. Membrane-assisted solvent extraction was successfully applied to a fast screening method dedicated to an unknown wastewater sample.     

Characterization and Semiquantitative Analysis of Volatile Compounds in Orange Juice by Use of Headspace-Solvent Microextraction and Gas Chromatography

By alternate use of two different extraction solvents, n-hexadecane and benzyl alcohol, a headspace-solvent microextraction (HSME)–GC–FID/MS method has been established for characterization of the volatile components of an orange juice beverage. The method avoids two disadvantages of conventional HSME—difficulty identifying components obscured by the solvent peak and inefficient extraction of some of the compounds if one solvent only is used. The optimum conditions (droplet volume, equilibration temperature and time, extraction time, and ionic strength) were determined by the factor-rotation method. The volatile components of the beverage were mainly terpenes, terpenols, fatty acids, and alcohols, for example limonene (114.71 mg L⁻¹), phellandrene (4.50 mg L⁻¹), terpineol (p-menth-1-en-8-ol; 3.12 mg L⁻¹), α-pinene (0.33 mg L⁻¹), n-hexadecanoic acid (0.28 mg L⁻¹), and terpinol (0.13 mg L⁻¹).     

Structure of a new xanthone from <Emphasis Type="Italic">Securidaca inappendiculata</Emphasis>

A new xanthone (1, 1,7-dihydroxy-2-methoxyxanthone), in addition to the known metabolites 1,7-dihydroxyxanthone (2), 24(R)-stigmast-7,22 (E)-dien-3α-ol (3), and 1,7-dimethoxyxanthone (4), was isolated from the roots of Securidaca inappendiculata. Compounds 1–4 were evaluated by anti-HIV assay and 1–3 showed anti-HIV-1inhibitory activity in vitro. Published in Khimiya Prirodnykh Soedinenii, No. 3, pp. 348–349, July–August, 2008.     

Degradation of an ether–alcohol (3-ethoxypropan-1-ol) by photo-Fenton-generated <Superscript>•</Superscript>OH radicals: products analysis and formation pathways; relevance to atmospheric water-phase chemistry

We have chosen 3-ethoxypropan-1-ol (EtOPrOH) as a typical short-carbon-chain ether–alcohol used as industrial solvent and have analyzed the degradation products resulting from its attack by ^•OH radicals generated by the photo-Fenton reaction. The laboratory conditions were representative of those found in tropospheric water droplets. Twelve products have been identified by use of GC–MS analysis, either directly or after extraction by SPME fibers, and by HPLC–UV analysis with a special column for carboxylic acids and after reaction of carbonyl groups with 2,4-dinitrophenylhydrazine. These products contain one to three carbon atoms (instead of five in EtOPrOH), among which one or two are oxidized. According to the reaction pathways proposed, seven products—including methanal—can result from attack by one ^•OH only, three products imply attack by a second ^•OH, as expected from their higher oxidation number, and it is suggested that reaction between two organic radicals is needed for formation of only two products. The relevance of this investigation to the fate of EtOPrOH and similar ether–alcohols in the troposphere is briefly discussed.     

Kinetics and mechanism of the gas-phase thermal decomposition of cis-2-methylcyclopropane methanol

The kinetics of the gas-phase thermal decomposition of cis-2-methylcyclopropane methanol was studied in the temperature range of 483–597 K and pressures between 5–24 Torr in aged Pyrex reactions vessels. Cis-2-methylcyclopropane methanol underwent first order, reversible geometric isomerization in competition with structural isomerization. The structural isomerization products were identified as 2-peten-1-ol and a mixture of cis and trans-2-methyl-buten-1-ol. Arrhenius parameters were determined for homogeneous, unimolecular formation of the isomeric products and for the overall loss of reaction. The formation of isomeric products and the observed Arrhenius parameters are consistent with a biradical mechanism. For the overall reaction, E_a = 173.8 ± 15.5 (kJ/mol) and log10 (A, s⁻¹) = 13.3 ± 1.5. These values are in good agreement with previously reported values for similar studies of 1,2, disubstituted cyclopropanes.     

Anomalies in the Change of Volumetric Parameters of the Diels–Alder Reaction in Solution

In this article negative values of the activation volume in retro-Diels–Alder reactions are interpreted in terms of the different possibilities of penetration of the solvent molecules into the sterically branched structures of the adduct and activated complex. Empty spaces, inaccessible to penetration of solvent molecules, lead to increases of the molar volume of the screened adducts in solution and, consequently, to a less negative value of the Diels–Alder reaction volume. The values of partial molar volumes of anthracene, maleic anhydride and the adducts cyclopentadiene–maleic anhydride, anthracene–maleic anhydride and anthracene–tetracyanoethylene, in several solvents, were calculated from the solution density data.     

Synthesis and photoluminescence properties of 8-hydroxyquinoline derivatives and their metallic complexes

Three new 8-hydroxyquinoline derivatives, i.e. 5-[(4-styryl-benzylidene)-amino]-quinolin-8-ol (1), 5-[(4-bromo-2-fluoro-benzylidene)-amino]-quinoline-8-ol (2) and 2-[2-(9-ethyl-9H-carbazol-2yl)-vinyl]-quinolin-8-ol (3), and their metallic complexes were synthesized and identified by ultraviolet-visible (UV-Vis), ¹H nuclear magnetic resonance (¹H NMR), Fourier transform infrared spectrometer (FTIR), mass spectrometry (MS) spectra and elemental analyses. Their fluorescence properties were studied by photoluminescence, which indicated that the luminescence wavelength of 5-and 2-substitued-8-hydroxyquinoline derivatives shifted to red in comparison with that of 8-hydroxyquinoline. Meanwhile, the fluorescence lifetime of 2-[2-(9-ethyl-9H-carbazol-2yl)-vinyl]-quinolin-8-ol and its zinc complex showed long lifetime in benzene solution. __________ Translated from Chinese Journal of Organic Chemistry, 2007, 27(3): 402–408 [译自: 有机化学]