7664-93-9

One-stage size-selective method of laser electrodispersion (LED) was used to produce nanostructured NiPd, NiMo and NiW coatings on the surface of alumina, HOPG and Sibunit for the catalytic application. The deposition of nanoparticles produced by LED of b

In pollution control applications, the presence of water in the electrical discharge enhances oxidation of pollutants. The results of an electrical discharge in gas when it flows through a heterogeneous mixture of water and dielectric pellets are reported. The discharge in the wet plasma reactor is more uniform compared to dry dielectric-barrier reactors. The electrical characteristics of such a discharge are discussed. Also the results of removal of SO2 with the wet reactor are reported. The wet reactor was found to be 5-10 times more energy efficient in removing SO2 compared to conventional dry plasma reactors.

The photoinitiated and cerium(III)-catalyzed aqueous reaction between sulfite ion and oxygen has been studied in a diode-array spectrophotometer using the same light beam for excitation and detection. Cerium(III) is identified as the photoactive absorbing species, and the production of cerium(IV) initiates a radical chain reaction. To interpret all the experimental findings, a simple scheme is proposed, in which the additional chain carriers are sulfite ion radical (SO3-.), sulfate ion radical (SO4 -.), and peroxomonosulfate ion radical (SO5-.). The overall rate of oxidation is proportional to the square root of the light intensity per unit volume, which is readily interpreted by the second-order termination reaction of the proposed scheme. It is also shown that the reaction proceeds for an extended period of time in the dark following illumination, and a quantitative analysis is presented for this phase as well. The postulated model predicts that cerium(III) should have a cocatalytic or synergistic effect on the autoxidation of sulfite ion in the presence of other catalysts. This prediction was confirmed in the iron(III)-sulfite ion-oxygen system. The experimental method and the mathematical treatment used might be applicable to a wide range of photoinduced chain reactions.

Reactions between HgO, PbO, or PbO2 and 2.5-95 wt.% H2SO4 are studied at temperatures up to the boiling point of the acid. Depending on the oxide reactant, the H2SO4 concentration, and synthesis tempe

A model of photolysis of PbS2O3 aqueous solutions has been proposed on the basis of identified photolysis products and semiempirical quantum-chemical calculations. The degradation of PbS2O3 starts with the dissociation of the sulfur-sulfur bond in the thiosulfate group via photochemical excitation and transition of the system a whole to the activated state, which is decomposed by the solvent. The interaction of the primary photolysis products with PbS2O3 results in the formation of final products.

Combustion-produced soot (carbonaceous) particles have been found to be efficient catalysts for SO2 oxidation, especially in the presence of liquid water.A kinetic study of the catalytic oxidation of SO2 on carbon particles suspended in solution has been carried out.The reaction was found to be first order with respect to the concentration of carbon particles, 0.69th order with respect to dissolved oxygen, between zero and second order with respect to S(IV) concentrations, and independent of the pH.Temperature studies were carried out, and an activation energy for this reaction was determined.A four-step mechanism is proposed for this carbon-catalyzed oxidation reaction.

The interaction of SO3 and H2O at low temperatures upon an inert surface has been studied with infrared spectroscopy and compared to the predictions of recent computational studies. At low temperatures and low water partial pressures, amorphous deposits of molecular H2SO4 complexed with variable amounts of H2O in a ratio of between 1:1 and 2:1 are formed. Upon annealing, this material ejects water and converts first to a 1:1 H2SO4·H2O complex and subsequently to anhydrous H2SO4. Adding water to the amorphous molecular hydrate results in the formation of a new species, which on the basis of its thermal behavior and by comparison to theoretical predictions can be attributed to a molecular polymer with a repeat unit of (H2SO4·(H2 O)2)n. Implications of these observations for the initial stages of the formation of sulfate aerosol in the atmosphere and their surface reactivity are discussed.

The rate constants for the reaction of S03 with H20 in He and in Nz were measured at total pressures from I-10 Torr in a flow tube at room temperature.The concentration of S03 was monitored by photofragment emission produced by 147 nm excitation.Dependencies of apparent reaction rates on wall conditions and reaction tube sizes were investigated.At total He pressures of 1-10 Torr, a value of ( 5.7 +/- 0.9 ) X 10-15 cm3/s was obtained for the upper limit of the homogeneous gas phase reaction rate constant.This rate value is more than two orders of magnitude lower than the previously published value, but it is consistent with the theoretical calculation provided in this paper.

A stopped-flow kinetic study of the oxidation of sulfur dioxide by hydrogen peroxide was performed over the pH range 0.0-4.5.A rate expression of the following form was verified experimentally: d/dt = k1Ka1(k2+> + k3)/-1 + k2+> + k3)(Ka1 + +>)>.The following kinetic parameters at 15 deg C were determined: k1 = (2.6 +/- 0.5)*106 M-1 s-1, k2/k-1 = 16 +/- 4 M-1, k2/k3 = (5 +/- 1)*102 (HA = acetic acid), ΔH(excit.)1 = 37 +/- 2 kJ mol-1, and ΔS(excit.)1 = 4 +/- 4 J K-1 mol-1.The reaction proceeds via a nucleophilic displacement of HSO3-1 by H2O2 to which undergoes sulfurous acid intermediate which undergoes acid-catalyzed rearrangement to form product: SO2*H2O HSO3- + H+(Ka1), H2O2 + HSO3- HOOSO2- (k1, k-1), HOOSO2- + H+ -> H+ + HSO4- (k2), HOOSO2- + HA -> HA + HSO4- (k3).Application of the above rate expression to reactions occuring in hydrometeors is discussed.

Highly uniform γ-MnO2 3D urchinlike and sisallike nanostructures have been successfully prepared by a common hydrothermal method based on the reaction between MnSO4 and KBrO3. Reaction temperature and the additives of the polymers play an important role in influencing the morphologies of the as-obtained products. These urchinlike and sisallike nanostructures, which own the highly specific area on the surface of the particles may provide more possibility to give an ideal host material for the insertion and extraction of lithium ions, to realize region-dependent surface reactivity, and to act as molecular sieves.

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A method for producing a methanol precursor, methyl trifluoroacetate, having high-purity includes the steps of (a) preparing methyl bisulfate by mixing a catalyst with an acid solution comprising a sulfur-containing acid to provide a first mixture and supplying methane gas to the first mixture to prepare the methyl bisulfate; and (b) preparing methyl trifluoroacetate (CF3CO2CH3) by adding trifluoroacetic acid (CF3CO2H) to the first mixture including the methyl bisulfate to provide a second mixture and distilling the second mixture under heating to prepare, separate and purify the methyl trifluoroacetate (CF3CO2CH3). Methanol may be produced by adding water to the methyl trifluoroacetate (CF3CO2CH3). A methyl ester represented by Formula 2 below may be produced by adding a carboxylic acid represented by Formula 1 below to the methyl trifluoroacetate (CF3CO2CH3): R1CO2H??(1),where R1 is selected from C1-C10 alkyl groups, R1CO2CH3??(2),where R1 is as defined in Formula 1.

Abstract: The catalytic properties of W- and NiW-layered structures obtained by laser electrodispersion (LED) and plasma electrolytic oxidation (PEO) are investigated in oxidative desulfurization reactions. A comparative analysis of the effect of the comp

The invention discloses a para-ester synthesis process capable of recycling hydrogen chloride, which is characterized by comprising the following steps: (1) preparing chlorosulfonic acid; absorbing the hydrogen chloride gas generated in the chlorosulfonation link through an original HCl absorption tower, and resolving to generate pure hydrogen chloride gas; reacting the hydrogen chloride gas withpure sulfur trioxide gas in a primary reaction tower to obtain gaseous chlorosulfonic acid; condensing the gaseous chlorosulfonic acid and entering in a secondary reaction tower, and fully reacting aside reaction product in the primary reaction tower with excessive sulfur trioxide and hydrogen chloride to further generate chlorosulfonic acid; (2) preparing para-ester; preparing chlorosulfonated substances in a sulfonation reaction kettle; diluting and carrying out suction filtration, and then carrying out a reduction reaction, a condensation reaction and an esterification reaction to preparethe para-ester. The hydrogen chloride generated in the chlorosulfonation link is recovered and reacts with sulfur trioxide gas to prepare chlorosulfonic acid, the chlorosulfonic acid serves as a raw material in the chlorosulfonation link, the para-ester is further prepared, and cyclic utilization is achieved.

Although chloride-ligated Pt compounds like (bpym)PtCl2, K2PtCl4, and (DMSO)2PtCl2 has been reported to be highly active catalysts for the methane oxidation to methyl bisulfate (MBS) in oleum media, their applications is hampered by the catalyst deactivation to PtCl2. In this study, we investigated Pt black catalyzed methane oxidation, which has no ligand. A MBS yield of 82.1% with a selectivity of 96.5% was obtained at a catalyst loading of 1.6 mM at 180 °C, which proved the highest catalytic activity of Pt-black for this reaction. The reaction was thought to proceed by the dissolved Pt species, and no deactivation was observed during four consecutive experiments. However, at a concentration of over 30 mM, MBS yield fell due to the decomposition of MBS to CO2 on the surface of heterogeneous Pt(0). Vacuum distillation experiments showed the potential for isolating MBS from the oxidation product mixture as a major component.

In this paper, the decomposition mechanism of Thiourea dioxide (TDO) aqueous solution in 25–95 °C temperature range were studied in detail by electrode potential method, time-of-flight mass spectrometry (TOF-MS), Raman spectroscopy and quantum chemistry calculations. Oxidation-Reduction Potential (ORP) were used to reveal the effect of temperature on the reduction performance of TDO. TOF-MS and Raman spectroscopy were used to determine the chemical constituents of TDO solution at different temperatures. Quantum chemistry calculations were used to assign Raman spectra. This work provides solid theoretical and experimental evidences for the decomposition mechanism of TDO in moisture-hot condition.

6-Propylthiouracil, PTU, is a well-known antithyroid drug that has been the mainstay of treatment of Graves' disease. It is, however, also associated with liver toxicity and idiosyncratic toxicity. These toxicities are generally associated with metabolites derived from its bioactivation. In this manuscript, bioactivation of PTU was studied via two separate techniques: Electrochemical oxidation and through the use of human liver microsomes. The aim of this work was to compare the bioactivation products of these two techniques. The electrochemical technique was studied online with a mass spectrometer, EC/ESI/MS. The microsomal oxidations were studied in tandem with liquid chromatography. The EC/ESI/MS technique was devoid of the normal reducing biological matrix prevalent in microsomal incubations. The predominant product at 400 mV was the dimeric PTU species with negligible formation of other metabolites. At higher potentials, complete desulfurization of PTU was observed with formation of sulfate. No sulfonic acid was observed, suggesting that the cleavage of the C-S bond was effected at the sulfinic acid stage, releasing a highly reducing sulfur species which is known to give rise to genotoxicity. The microsomal oxidations, surprisingly, showed formation of the unstable sulfenic acid, the S-oxide. Further incubation showed both the sulfinic and sulfonic acids. None of the systems showed any adducts with nucleophiles such as glutathione, showing that none of the reactive metabolites were stable enough to be adducted to nucleophiles in both the biological matrix and the electrochemical oxidizing environment.

Criegee intermediates are thought to play a role in atmospheric chemistry, in particular, the oxidation of SO2, which produces SO3 and subsequently H2SO04, an important constituent of aerosols and acid rain. However, the impact of such oxidation reactions is affected by the reactions of Criegee intermediates with water vapor, because of high water concentrations in the troposphere. In this work, the kinetics of the reactions of dimethyl substituted Criegee intermediate (CH3)2 COO with water vapor and with SO2 were directly measured via UV absorption of (CH3)2COO under near-atmospheric conditions. The results indicate that (i) the water reaction with (CH3)2 COO is not fast enough (kH2O -16 cm3s-1) to consume atmospheric (CH3)2COO significantly and (ii) (CH3)2COO reacts with SO2 at a near-gas-kinetic-limit rate (kSO2 = 1.3 × 10-10 cm3s-1). These observations imply a significant fraction of atmospheric (CH3)2 COO may survive under humid conditions and react with SO2, very different from the case of the simplest Criegee intermediate CH2OO, in which the reaction with water dimer predominates in the CH2OO decay under typical tropospheric conditions. In addition, a significant pressure dependence was observed for the reaction of (CH3)2COO with SO2, suggesting the use of low pressure rate may underestimate the impact of this reaction. This work demonstrates that the reactivity of a Criegee intermediate toward water vapor strongly depends on its structure, which will influence the main decay pathways and steady-state concentrations for various Criegee intermediates in the atmosphere.

The thermochemical cycle involving the interconversion between sulfur dioxide and sulfuric acid is a promising method for efficient, large-scale production of hydrogen. A key step in the process is the oxidation of sulfur dioxide to sulfuric acid in an el

Described herein is the isolation and identification of a number of sulfur oxidizing plant growth promoting rhizobacteria: RAY12, identified as Achromobacter piechaudii; RAY28, identified as Agrobacterium tumefaciens, RAY132, identified as Stenotrophomonas maltophilia; and RAY209, identified as Delftia acidovorans. The PGPR act to oxidize elemental sulfur which in turn provides sulfate for the plants. As a result of this arrangement, plants are able to grow more efficiently and effectively and have enhanced growth characteristics, for example, but by no means limited to, increased vigor, early emergence, increased emergence rate, increased biomass, increased plant leaf area, higher crop yield, increased pod number, increased pod weight, increased root biomass, increased seed weight, increased macro- and micro-nutrient uptake and the like. The sulfur-oxidizing PGPR may be applied to seeds, seed pieces, carrier materials, roots and planting soil.

Sulfuric acid contaminated with byproducts of chloromethane scrubbing is regenerated for reuse in the scrubbing process by diluting with water to not lower than about a 55 weight percent concentration, heating the diluted acid to boiling at not more than about 135° C., concentrating the acid to a concentration of minimally 80 weight percent at a temperature of at least 170° C., and reacting the concentrated acid with an oxidizing agent.

Imidazolium methylsulfites of the general formula (I) where the radicals have, independently of one another, the following meanings: R1 to R3: hydrogen, halogen, hydroxy, amino, aminocarbonyl, sulfo, cyano, nitro; C1-C20-alkyl, C2-C20-alkenyl, C2-C20-alkynyl, C1-C20-alkyloxy, C2-C20-alkenyloxy, C2-C20-alkynyloxy, C1-C20-alkylcarbonyl, C1-C20-alkyloxycarbonyl, C1-C20-acyloxy, C1-C20-alkylaminocarbonyl, di(C1-C20-alkyl)aminocarbonyl, C1-C20-alkylamino, di(C1-C20-alkyl)amino, C1-C20-alkylsulfonyl, C3-C8-cycloalkyl, where the alkyl, alkenyl, alkynyl and cycloalkyl groups mentioned can be substituted and/or have their CH2 groups replaced by oxygen; phenyl, phenoxy, where these can in turn be substituted; R4: sulfo; C1-C20-alkyl, C2-C20-alkenyl, C2-C20-alkynyl, C3-C8-cycloalkyl, where the alkyl, alkenyl, alkynyl and cycloalkyl groups mentioned can be substituted and/or have their CH2 groups replaced by oxygen; phenyl, where this can be substituted; or R1 together with R4, and/or R2 together with R3, or R4 together with R2: alkylene —(CH2)n— where n=4, 5 or 6 or butadienylene —CH═CH—CH═CH—, where these can be substituted and/or have the CH2 groups replaced by oxygen and the CH groups replaced by NR5.

The rate of visible light induced oxidation of hydrazine by peroxodisulphate in the presence of tris-(2,2′-bipyridine)ruthenium(II) [Ru(bipy)32+] in aqueous solution is independent of the substrate concentration but increases with the intensity of light absorbed as follows: Ki=kqIaφ[S2O 82-] [Ru(bipy)3]2+/k 0+kq[S2O82-] where k i is the initial rate and other the terms have their usual meaning.

The present invention relates to a method of removing SO2 contaminants from dimethyl sulfate (DMS) by treatment with an oxidizing agent, and to a process for the preparation of odour free fatty acid trialkanolamine esters quaternized with DMS which is substantially free of SO2 contaminants.

Anhydrous processing to convert methane into oxygenates (such as methanol), liquid fuels, or olefins uses an initiator to create methyl radicals. These radicals combine with sulfur trioxide to form methyl-sulfonate radicals. These radicals attack fresh methane, forming stable methane-sulfonic acid (MSA) while creating new methyl radicals to sustain a chain reaction. This system avoids the use or creation of water, and liquid MSA is an amphoteric solvent that increasing the solubility and reactivity of methane and SO3. MSA from this process can be sold or used as a valuable chemical with no mercaptan or halogen impurities, or it can be heated and cracked to release methanol (a clean fuel, gasoline additive, and chemical feedstock) and sulfur dioxide (which can be oxidized to SO3 and recycled back into the reactor). MSA also can be converted into gasoline, olefins, or other valuable chemicals.

Energizing formulations of phosphorous and potassium fertilizer are disclosed that comprise maximally efficient phosphorous pentoxide and di-potassium monoxide combinations. Methods of manufacture and use for these compounds and formulations are also disclosed. The fertilizer formulations comprise both solid and liquid formulations having variable or fixed pH ranges that are acceptable for aerial, foliar, and soil applications, and suitable for all forms of perennial trees, vines and annual crops. The formulations further possess the ability to control pathogenic soil microorganisms through the use of, for example, formulations comprising combinations of monopotassium phosphite, monopotassium phosphate. monopotassium nitrite, monopotassium nitrate, monopotassium sulfite and monopotassium sulfate.

The high-resolution (0.05 cm-1) spectra of gas-phase H 2SO4, HDSO4, and D2SO4 were measured over the frequency region 1200-10,000 cm-1 using Fourier-transform infrared spectroscopy. The increased resolution of this work compared with previous studies has lead to an improved vibrational analysis of H2SO4. This study has answered unresolved questions about combination bands and overlapping features from previous gas-phase spectroscopic studies of H2SO4 and marks the first experimental measurement of the ν8 and ν15 torsional vibrations in this molecule. This work leads to a brief discussion on vibrational mode mixing in sulfuric acid.

Measurements of the electrical conductivity were performed in KHSO 4 at pressures between 0.5 and 2.5 GPa and in the temperature range 120-350 °C by the use of the impedance spectroscopy. The temperatures of the α-β phase transition (TTr) and of the melting (T m), determined from the Arrhenius plots ln(σT) vs. 1/T, increase with pressure up to 1.5 GPa having dT/dP～+45 K/GPa. Above the pressure 1.5 GPa, the pressure dependencies of TTr and Tm are negative dT/dP～-45 K/GPa. At pressures above 0.5 GPa, the reversible decomposition of KHSO4 into K3H(SO4) 2+H2SO4 (and probably into K5H 3(SO4)4+H2SO4) affects the electrical conductivity of KHSO4, with the typical values of the protonic electrical conductivity, c. 10-1 S/cm at 2.5 GPa.

Production of methyl-substituted unsaturated macrocyclic ketones or lactones (I) comprises Grignard reaction of a macrocyclic diketone or ketolactone (II) with a methyl magnesium halide followed by acid dehydration. Production of methyl-substituted unsaturated macrocyclic ketones or lactones of formula (I) comprises Grignard reaction of a macrocyclic diketone or ketolactone of formula (II) with a methyl magnesium halide followed by acid dehydration: Z' = CH2 or O; n = 0 or more, but not 0 when Z is CH2; m = 1 or more; n+m = 11-15; one dotted line denotes a C-C single bond and the other denote a C = C double bond. Independent claims are also included for: (1) new compounds (Ia), i.e. 5-methyl-4(E/Z)/5(E/Z)-cyclopentadecenone, 4-methyl-3(E/Z)/4(E/Z)-cyclohexadecenone, 6-methyl-5(E/Z)/6(E/Z)-cyclohexadecenone, 3-methyl-2(E/Z)/3(E/Z)-cycloheptadecenone, 9-methyl-8(E/Z)/9(E/Z)-cycloheptadecenone, 4-methyl-1-oxa-3(E/Z)/4(E/Z)-cyclopentadecen-2-one, 5-methyl-1-oxa-4(E/Z)/5(E/Z)-cyclopentadecen-2-one, 6-methyl-1-oxa-5(E/Z)/6(E/Z)-cyclopentadecen-2-one, 13-methyl-1-oxa-12(E/Z)/13(E/Z)-cyclopentadecen-2-one, 4-methyl-1-oxa-3(E/Z)/4(E/Z)-cyclohexadecen-2-one, 5-methyl-1-oxa-4(E/Z)/5(E/Z)-cyclohexadecen-2-one, 13-methyl-1-oxa-12(E/Z)/13(E/Z)-cyclohexadecen-2-one, 5-methyl-1-oxa-4(E/Z)/5(E/Z)-cycloheptadecen-2-one and 13-methyl-1-oxa-12(E/Z)/13(E/Z)-cycloheptadecen-2-one; (2) compounds of formula (IV) and (VI) other than (IV;n=1,m=11); (3) production of (IV) and (VI) by Grignard reaction of (II) with a methyl magnesium halide; (4) fragrance mixtures comprising (Ia); (5) perfumed products comprising (Ia).

The invention relates to novel heterocyclic compounds of general formula (I), and their salts with a base or an acid: The invention also relates to a method for preparing these compounds, and to their use as medicaments, in particular as antibacterials and β-lactamase inhibitors.

Use of certain nitrate ester compounds or pharmaceutically acceptable salts thereof in the manufacture of a medicament for treating pain or providing analgesia.

Compounds of formula 1 are effective modulators of PI3 kinase: wherein R1 is H, hydroxy, amino, lower alkyl, or trihalomethyl; R2 is amino, lower alkylamino, lower acylamino, arylamino, arylacyl-amino, heteroaryl-amino, heteroaryl-acyl amino, where aryl and heteroaryl are substituted with 0-3 substituents selected from the group consisting of halo, trihalomethyl, hydroxy, lower alkyl and lower alkoxy, or a substituent of the form —(CH2)n—C(═X)—R8, where n is 0-3 inclusive and X is O or NR9, where R9 is H, lower alkyl, or R1, and R2 together form —CH═N—X—where X is CH, NH, O, or S, and R8 is H, lower alkyl, lower alkoxy, aryl, aralkyl, or —(CH2)mCR10R11R12, where m is 0-3 inclusive, and R10, R11, and R12 are each independently H, lower alkyl, aryl, aralkyl, hydroxy, lower alkoxy, aryloxy, aralkoxy, amino, lower alkyl-amino, arylamino, aralkylamino, heteroaryl amino, or heteroaralkyl amino, where aryl and heteroaryl are substituted with 0-3 substituents selected from the group consisting of halo, hydroxy, and lower alkyl; R3 is H or lower alkyl; and R4, R5, R6, R7 are each independently H, halo, hydroxy, amino, nitro, lower alkyl, or lower alkoxy; and pharmaceutically acceptable salts thereof.

Novel sulfur-containing analogs of 1α,25-dihydroxy vitamin D3are provided. These analogs are synthesized in a convergent manner by joining A-ring and C,D ring fragments. Each analog with 1α,3β-substituent stereochemistry shows a pharmacologically desirable combination of high antiproliferative and high transcriptional activities in vitro and also low calcemic activity in vivo.

The present invention concerns novel paclitaxel derivatives, their use as antitumor agents, and pharmaceutical formulations.

Oxidation of sulfurous acid (H2SO3) to sulfuric acid (H2SO4) by dissolved oxygen (O2) in an aqueous solution was remarkably enhanced by freezing. The concentration of sulfurous acid in a sample solution which froze in a -10°C refrigerant for 60 min decreased by about 50%, and three freeze/thaw cycles resulted in perfect conversion into sulfuric acid. The difference of reaction rates in -20°C and -10°C refrigerants indicated that the rate-determining step of the reaction was the growth rate of ice formation in the sulfurous acid in an aqueous solution. The yield of sulfurous acid oxidation in a -10°C refrigerant was higher than that in a -20°C refrigerant.

Prodrugs of formula I, their uses, their intermediates, and their method of manufacture are described:

Temperature dependence studies of adsorption of sulfuric acid species on Pt(111) and Au(111) electrodes were carried out using in situ infrared reflection absorption spectroscopy. A temperature-dependent shift of the interconversion potential between HSO4-/H3O+ and H2SO4 on a Pt(111) electrode was observed. A temperature-dependent frequency shift of the absorption bands of HSO4- was also observed on both Pt(111) and Au(111) electrodes in the potential region where a √3×√7 structure evolved. Modelling experiments in ultrahigh vacuum revealed that ordering of the overlayer water molecules played an important role in the frequency of the absorption bands of HSO4-.

A process for production of a t-alkyl peroxide compound includes the steps of: a) reacting an n-alkyl t-alkyl ether with a reactant mixture comprising an acid catalyst and a compound of the formula RO2H??(I) ?where R is H or t-alkyl, provided that if R is t-alkyl the t-alkyl peroxide compound product is a di-t-alkyl peroxide, and b) isolating a reaction product comprising said t-alkyl peroxide compound from the mixture resulting from step a). The process can be used to prepare t-butyl hydroperoxide or di-t-butyl peroxide from methyl t-butyl ether. Sulfuric acid may be used as the acid catalyst.

We measured the rates of carbonyl sulfide (OCS) oxidation by hydrogen peroxide H2O2 (HP) and peroxymonosulfuric acid HOOSO2OH (PSA) in 13.5-18.0 M (76-96 wt%) sulfuric acid (SA) between 290 and 306 K. The reaction is first

The reproportionation reactions of nitrogen compounds, used for reduction of nitrogen oxide exhausts of nitric acid metal etching industry are examined. A kinetic study of reactions of nitrous acid with urea and sulfamic acid is performed, and kinetic equations for these reactions are proposed. The stoichiometry of the reaction of urea with nitrous acid is determined.

Metallocene compounds with two indenyl-type ligands linked in the 4 position by means of a divalent bridging group can be suitably used as components of catalysts for the polymerization of olefins. In particular, it is possible to prepare saturated or unsaturated elastomeric copolymers of ethylene characterized by valuable properties, such as low ash content and uniform distribution of the comonomers in the polymer chain. Metallocenes of the following generic structure are disclosed:

A simple and easy preparative route to obtain permanganic acid and permanganate salts from barium manganate and sulphuric acid is described. Sulphuric acid reacts with barium manganate to produce sparingly soluble barium sulphate and well-soluble permanganic acid or barium permanganate, these in turn can be used to prepare other metal permanganates.

Compounds of the formula I according to claim 1 are excellently suitable as UV absorbers for use in cosmetic products, in particular sunscreen compositions, daytime care products and hair care products. They are furthermore suitable for protection of products.

An improved method for synthesis of Annamycin is described. The synthesis relies upon a method of selectively deacetylating the Annamycin precursor and purification of the deacetylated product by a filtration step. In addition, the method includes an improved method for desilylating the Annamycin precursor that utilizes acidic conditions. Lastly, improved purification methods of the final Annamycin product are disclosed.

The present invention concerns novel paclitaxel derivatives, their use as antitumor agents, and pharmaceutical formulations.

Four novel oxovanadium(IV) binuclear complexes have been synthesized and identified [(VO)2(BA)L2]SO4 [L denotes 2,2'-bipyridine (bpy); 1, 10-phenanthroline (phen); 2,9-dimethyl-1, 10-phenanthroline (Me2-phen) and 5-chloro-1, 10-phenanthroline (Cl-phen), respectively], where BA represents the dianion of bromanilic acid. The complexes were characterized by elemental analyses, molar conductivity and room temperature magnetic moment measurements, IR and electronic spectral studies. Based on these studies, extended BA-bridged structures consisting of two vanadium(IV) ions, each in a square-pyramidal environment, are proposed for these complexes. The complexes [(VO)2(BA)(bpy)2]SO4 (1) and [(VO)2(BA)(phen)2]SO4 (2) were characterized by variable temperature present complexes than that of the complexes [(VO)2(CA)L2]SO4 (L = bpy and phen), so as to increase the antiferromagnetic interaction. This would explain the difference in J values for these complexes.

The present invention discloses compounds of the formula, STR1 any mixture thereof, or a pharmaceutically acceptable salt thereof; wherein R, R3, and R4 each have the meanings set forth in the specification. The compounds possess valuable pharmaceutical properties as monoamine neurotransmitter, i.e dopamine, serotonin, noradrenalin, reuptake inhibitors.

It has been known that administration of pharmaceutical agents (both diagnostic and therapeutic) with poor water solubility in the form of particles less than 400 nm in diameter produces agent formulation with increased bioavailibility. Bioavailability being proportional to the surface area, increases with reduction of particle size of the dispersed agent. We have discovered that chemical derivatization of certain photographic coupler molecules with chemical moiety that are capable of functioning as pharmaceutical agents (both diagnostic and therapeutic) is amenable to the preparation of nanoparticulate pharmaceutical agent dispersions via a process that comprises the dissolution of the said pharmaceutical agent in an alkaline solution and then neutralizing the said solution with an acid in the presence of a suitable surface-modifying, surface-active agent to form an ultra fine particle dispersion of the said pharmaceutical agent. The composition and process of this invention leads to particles of Z-average diameters as small as up to 10 nm as measured by photon correlation spectroscopy. The composition and process schemes of this invention are suitable for large-scale manufacture of these micro-nanoparticulate pharmaceutical agent dispersions.

The invention is related to a method for preparing 4-alkyl-2-hydroxy-3,5-dichlorobenzene sulphonic acids by sulphonating 4-chloro-3-alkylphenol and by chlorinating 4-alkyl-2-hydroxy-5-chlorobenzene sulphonic acid present in an acidic reaction mixture. According to the invention, chlorination is carried out by adding, to the acidic reaction mixture, salts of hypochlorous and/or chloric acids and, when needed, hydrochloric acid or its salt.

This article demonstrates quantitatively how far reactions are from chemical equilibrium over the full space of a two-dimensional atmospheric model. This method could be used with data where an instrument-equipped aircraft measures numerous species simultaneously. An atmospheric reaction is displaced from equilibrium by solar radiation and relocation of species by atmospheric motions. One purpose of this study is to seek additional stratospheric or tropospheric gas-phase chemical reactions that might undergo heterogeneous catalysis. Hypothetical cases can be rapidly screened in terms of their thermodynamic potential to react under measured or modeled atmospheric conditions of temperature and local species concentrations. If a reaction is interesting, is slow in the gas phase, and has a high thermodynamic tendency to react, it is a good candidate for a laboratory study to seek a heterogeneous catalyst. If the reaction is thermodynamically unfavorable, there is no catalyst that can cause the reaction to occur. If a reaction is thermodynamically favored to occur but also endothermic, it will tend to be slow at stratospheric temperatures. We find, as expected, that four heterogeneous reactions important in causing the Antarctic ozone hole have high thermodynamic tendencies to occur under atmospheric conditions, but one of these is only weakly thermodynamically allowed in some regions of the atmosphere. The reaction of SO2 and HNO3 to form HONO has a high thermodynamic potential to occur, is a well-known laboratory reaction at ice temperature, and may occur in nitric acid-rich sulfate aerosols. Throughout the troposphere and stratosphere, we find that formaldehyde has an extremely high thermodynamic potential to reduce nitric acid. Formaldehyde is known to stick to and remain in sulfuric acid solution, where it adds water to form H2C(OH)2. Near room-temperature H2C(OH)2 reacts with nitric acid in a two-step mechanism to form two molecules of HONO, but the rate of this process under conditions of stratospheric sulfuric acid aerosols is unknown.

An alkyl (meth)acrylate is prepared by a direct esterification (in 1) of (meth)acrylic acid by the corresponding alcohol, catalysed by H2 SO4. To the crude reaction mixture (C1) comprising the desired ester, alcohol, (meth)acrylic acid, alkyl hydrogen sulphate and traces of H2 SO4, there is added (in 3) a base to neutralize the acidic species, the resulting salts passing into the aqueous phase (A1), which is separated from the organic phase (O1) containing the desired ester. The light products (L1) containing the alcohol are recovered (in 4) from the aqueous phase, and the waste waters (W2) are expelled. A hydrolysis is carried out (in 8) of the alkyl hydrogen sulphate present in the aqueous phase (A1) obtained after the separation which is carried out after neutralization (in 3), to form the alcohol and H2 SO4 in this phase, the acidic species resulting from the hydrolysis are neutralized by introduction of a base .into the medium, and the resulting aqueous phase (A3) is directed to the step for recovery of the alcohol. Pollution of the waters (W2), attributable to the alkyl hydrogen sulphate, is thus avoided.

The growth and characterization of ultrathin (ca. 80 monolayers) films of pure, crystalline sulfuric acid and of the liquid H2SO4 + H2O azeotrope in ultrahigh vacuum (UHV) are described.The films, which were deposited on a Pt(111) substrate, were synthesized in vacuo via the reaction of co-condensed mixtures of H2O and SO3.Fourier transform infrared reflection-absorption spectroscopy (FTIRAS) shows that the pure, crystalline acid forms when such mixtures are briefly annealed at 260 K.Crystalline H2SO4 is stable in UHV until 285 K, at which temperature FTIRAS measurements suggest the melting occurs.The melting temperature is equal, within experimental error, to the melting point of a macroscopic sample of crystalline H2SO4.Analysis of the gas phase composition during melting reveals that SO3 is expelled from a film as it melts.The liquid is identified as the azeotrope of H2SO4 and H2O, formed in the incongruent melting of H2SO4.The H2SO4 + H2O mixtures can be supercooled to 255 K.Freezing results in the formation of pure, crystalline H2SO4 and is accompanied by the expulsion of H2O into the gas phase.To our knowledge, this work provides the first observation of melting of a molecular solid under UHV.

Compounds having acidic protons and a molecular structure which can delocalize the electron density of the conjugate base (target compounds) are chlorinated by contacting such compounds with a perchloroalkane and aqueous base in the presence of a phase transfer catalyst which is an tetraalkylammonium hydroxide. Chlorinated products, preferably gem-dichloro compounds, are produced. The gem-dichloro compounds are useful for alkylation of aromatic compounds. For instance fluorene is chlorinated to form 9,9-dichlorofluorene which is reacted with such compounds as phenol or aniline to form such compounds as 9,9-bis(hydroxyphenyl)fluorene, 9,9-bis(aminophenyl)fluorene, or 9-aminophenyl-9-chlorofluorene.

Novel alcohols of the formula STR1 wherein Ra is azido or phthalimido, R4 is alkyl, cycloalkyl, cycloalkylalkyl, aryl or aralkyl, R7 and R8 together are a trimethylene or tetramethylene group which is optionally substituted by hydroxy, alkoxycarbonylamino or acylamino or in which one --CH2 -- group is replaced by --NH--, --N(alkoxycarbonyl)-, --N(acyl)- or --S-- or which carries a fused cycloalkane, aromatic or heteroaromatic ring, and R9 is alkoxycarbonyl, monoalkylcarbamoyl, monoaralkylcarbamoyl, monoarylcarbamoyl or a group of the formula STR2 in which R10 and R11 each is alkyl, are described along with a process for their manufacture. These alcohols are useful as intermediates, for example in the manufacture of amino acid derivatives having antiviral activity.