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Absolute dissociative ionization cross-sections from threshold to 200 eV have been measured using Fourier transform mass spectrometry (FTMS). In the production of positive ions by electron impact ionization, 13 ions are detected, including the parent ion

In one aspect, the disclosure relates to a method for functionalizing hydrocarbons. In a further aspect, the method involves heating a hydrocarbon with a composition having an acid and an oxidant. In other aspects, the composition can further include an iodine-based compound and/or a compound having formula AaXn. In any of these aspects, the oxidant can be regenerated in situ or in a separate regeneration step. Also disclosed are functionalized hydrocarbons produced by the disclosed method. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present disclosure.

Abstract: IR spectra of the gas phase formed during the interaction between gaseous CH3I and SiO2-based granular sorbents containing various silver compounds are studied. It is established that the main gaseous products formed by the

A green and efficient one-pot method has been developed for the synthesis of low-carbon chain nitroalkanes via a novel TS-1 catalyzed tandem oxidation of ketones with H2O2 and NH3. The tandem reaction including ammoxidation, oximation and oxidation of oximes, afforded up to 88% yield and 98% chemo-selectivity requiring only 90 min, at 70 °C and atmospheric pressure. Moreover, this method was even amenable to 100-fold scale-up without loss of chemical efficiency with 87% yield, represents a significant advance towards industrial production of nitroalkanes. Furthermore, the plausible mechanism of TS-1 catalyzed tandem oxidation of ketones to prepare nitroalkanes was proposed.

The invention belongs to the field of organic chemical industries, and provides a green synthesis method for preparing nitroalkanes by oxime oxidation. At the temperature of 55 to 120 DEG C and under the pressure of 0 to 1.0 MPa, oxime, a solvent and hydrogen peroxide are reacted for 20 to 200min in the presence of certain amounts of nanoporous skeleton metal hybrid catalysts and cocatalysts, a reaction liquid is subjected to membrane separation, the catalysts can be repeatedly used for more than 7 times, and distilled to obtain nitroalkane products, the purity of the products is not less than 99%, and the yield of the products is not less than 95%. Furthermore, the green synthesis method for preparing nitroalkanes by the oxime oxidation disclosed by the invention is a green synthesis method of nitroalkanes, and suitable for large-scale industrialized production.

Despite the high nucleophilicity of sulfur atoms, thiacalixarenes have been alkylated only on oxygen atoms thus far. Using strong alkylating agents (triflates, trialkyloxonium salts), the substitution of the sulfur bridges has been successfully accomplished. The corresponding sulfonium salts of thiacalix[4]arene are formed regio- and stereoselectively as a completely new type of substitution pattern in thiacalixarene chemistry. These compounds possess interesting conformational behavior and could be used as unusual alkylating agents with uncommon selectivity.

Disclosed are a process and an apparatus for synthesizing nitroalkanes by reaction of a hydrocarbon feedstock with aqueous nitric acid. Energy and capital costs may be reduced by recycling a majority of the aqueous phase back to the reactor.

Provided is a process for making nitrated hydrocarbons by reacting aqueous nitric acid with a hydrocarbon feedstock and a carboxylic acid under specific reaction conditions.

A method for the electrochemical synthesis of dinitro compounds is disclosed. The method comprises using an anode to oxidize an inactive chemical mediator, such as a ferrocyanide (Fe(CN)6?4) ion, to an active chemical mediator or oxidizing agent, such as a ferricyanide (Fe(CN)6?3) ion, in the presence of a differential voltage. The oxidizing agent reacts with a nitro compound and a nitrite ion to form a geminal dinitro compound. The anode may continuously oxidize ferrocyanide to regenerate active ferricyanide, thus keeping sufficient amounts of ferricyanide available for reaction.

A series of trifluoromethyl ketones as SARS-CoV 3CL protease inhibitors was developed. The inhibitors were synthesized in four steps from commercially available compounds. Three different amino acids were explored in the P1-position and in the P2-P4 positions varying amino acids and long alkyl chain were incorporated. All inhibitors were evaluated in an in vitro assay using purified enzyme and fluorogenic substrate peptide. One of the inhibitors showed a time-dependent inhibition, with a Ki value of 0.3 μM after 4 h incubation.

Alkyl halides are efficiently converted to their corresponding nitroalkanes under mild and nonaqueous conditions by using polymer supported nitrites. The polymeric reagent is regenerable.

The kinetics of the gas-phase elimination of several 2-substituted primary, secondary and tertiary hydroxy groups in nitroalkanes were determined in a static reaction system over the temperature range 220-400°C and pressure range of 29-235 Torr. The reactions, in seasoned vessels, are homogeneous and unimolecular and obey a first-order rate law. The presence of secondary and tertiary hydroxy substituent at the 2-position of the nitro group in nitroalkanes leads to a retro-aldol type of decomposition. The mechanism may be rationalized in terms of a six-membered cyclic transition state to give the corresponding aldehyde or ketone and the nitroalkane, respectively. However, some of the primary 2-hydroxy groups in nitroalkanes undergo a dehydration process with very limited isomerization to the corresponding alkyl nitrate. The mechanism of dehydration is believed to proceed through a six-membered rather than the already reported four-membered cyclic transition state to give the nitroalkene and water. In the case of the primary hydroxy substituent in 2-methyl-2-nitro-1-pentanol, the products of elimination are HNO2 gas and 3-hydroxy-2-methyl-1-propene. This reaction is rationalized in terms of a four-membered cyclic transition state type of mechanism. The kinetic and thermodynamic parameters of the hydroxynitroalkane substrates are presented and discussed. Copyright 2004 John Wiley & Sons, Ltd.

Nitration of light alkanes and the alkyl side-chain of aromatic compounds with NO2 and HNO3 was successfully achieved by the use of N-hydroxyphthalimide (NHPI) as a catalyst under relatively mild conditions. For example, the nitration of propane with NO2 catalyzed by NHPI at 100 °C for 14 h gave 2-nitropropane in good yield without formation of 1-nitropropane and cleaved products such as nitroethane and nitromethane. Various aliphatic nitroalkanes, which are difficult to prepare by conventional methods, could be selectively obtained by means of the present methodology by using NHPI as the key catalyst. In addition, the side-chain nitration of alkylbenzenes such as toluene was selectively carried out to lead to α-nitrotoluene without the ring nitration. The present reaction provides an efficient selective method for the nitration of light alkanes and alkylbenzenes, which has been very difficult to carry out so far.

Disclosed are (1) a method for preparing an aromatic secondary amino compound which comprises reacting an N-cyclohexylideneamino compound in the presence of a hydrogen moving catalyst and a hydrogen acceptor by the use of a sulfur-free polar solvent and/or a cocatalyst, and (2) a method for preparing an aromatic secondary amino compound which comprises reacting cyclohexanone or a nucleus-substituted cyclohexanone, an amine and a nitro compound corresponding to the amine in a sulfur-free polar solvent in the presence of a hydrogen moving catalyst, a cocatalyst being added or not added. In a further aspect, a method is provided for the preparation of aminodiphenylamine by reacting phenylenediamine and cyclohexanone in the presence of a hydrogen transfer catalyst in a sulfur-free polar solvent while using nitroaniline as a hydrogen acceptor.

Methylene chloride is difficult to separate from tetrahydrofuran by conventional distillation or rectification because of the proximity of their vapor pressures. Methylene chloride can be readily separated from tetrahydrofuran by extractive distillation. Effective agents are 1-pentanol, 1,2-butanediol and 3-nitrotoluene.

Disclosed are (1) a method for preparing an aromatic secondary amino compound which comprises reacting an N-cyclohexylideneamino compound in the presence of a hydrogen moving catalyst and a hydrogen acceptor by the use of a sulfur-free polar solvent and/or a cocatalyst, and (2) a method for preparing an aromatic secondary amino compound which comprises reacting cyclohexanone or a nucleus-substituted cyclohexanone, an amine and a nitro compound corresponding to the amine in a sulfur-free polar solvent in the presence of a hydrogen moving catalyst, a cocatalyst being added or not added.

Isopropanol is difficult to separate from 2-butanone by conventional distillation or rectification because of the proximity of their boiling points. Isopropanol can be readily separated from 2-butanone by extractive distillation. Effective agents are o-cresol, ethylene glycol and nitroethane.

A process for the conversion of a 4-chlorosulfonyl azetidinone (a) to a 3-hydroxy-3-cephem-sulfoxide ester (d) by subjecting an intermediate comprising a tin containing Lewis acid-type Fiedel-Crafts catalyst and 3-exomethylene cepham to ozonolysis.

It was shown that pure low-molecular nitroparaffins can be synthesized by the reaction between alkyl sodium sulfates and nitrite ion in ionic melts.The yield of the product is temperature controlled.Because of the ambident nature of nitrite ion, the main side product is alkyl nitrite, subsequent decomposition of which results in formation of a series of organic oxygen-containing compounds.The formal kinetics of the alkylation of nitrite ion by alkyl sodium sulfates was found to be described by the first-order equation.

Redox catalysis has been used to investigate the homogeneous electron-transfer reactions between the substrates (nitroalkane or diketone) and the reduced form of the catalyst, which was terephthalonitrile.The substrates were RNO2 (R=Me, Et, i-Pr, and t-Bu) and RC(O)C(O)R (R=Me, Et, and t-Bu).The experiments were conducted in acetonitrile solvent at 298 K with three different electrolytes, R4NClO4 (R=Et, n-Bu, and n-C7H15).The effect of added water and alcohols (methanol, ethanol, and s-butanol) was investigated.Formal potentials and standard heterogeneous electron-transfer rate constants, ks, were also determined.It was found that increasing the size of the cation of the electrolyte resulted in a decrease in ks but did not affect the rate of the homogeneous electron-transfer reactions.The result is interpreted as a decrease in electron-tunneling rate with increasing thickness of a compact layer of adsorbed cations, a double-layer effect that cannot influence the homogeneous reaction.Addition of the hydroxylic solutes, S, caused diminution of both ks and the rate constant of homogeneous electron transfer from the anion radical of the substrate to the catalyst.This result is discussed in terms of two models, viz., complexation or adduct formation between the anion radical and S or increasing solvation energy of the anion radical.

Novel compounds of the formula STR1 in which one of R30 and R40 represents a substituted phenylalkyl group, the other of R30 and R40 represents hydrogen or halogen, and R50 and R60 each independently represent hydrogen or alkyl; in addition R60 may represent a substituted alkyl chain interrupted by N. The compounds of the invention are useful for the treatment or prophylaxis of renal failure or cardiovascular disease.

Desilylative nitration of methyl- and ethylsilanes with nitronium tetrafluoroborate in sulfolane solution gives nitromethane and nitroethane, respectively.Higher alkylsilanes are also nitrated, but the reactions are followed by HNO2 elimination.The method represents the first successful nitrodesilylations at saturated carbon.Allylsilanes react cleanaly with NO2BF4 in methylene chloride solution to give nitropropanes in good to excellent yield.These reactions, however, involve initial attack by NO2+ on the allylic ?-system followed by fluoride-induced trimethylsilyl elimination and not direct desilylative nitration at saturated carbon. 1-(Trimethylsilyl)but-2-ene gives exclusive secondary 3-nitrobut-1-ene and not the primary direct nitrodesilylation product 1-nitrobut-2-ene.

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In the AgNO3-NaNO3-NaNO2-H2O system alkyl iodides RI are converted into nitroalkanes and alcohols.The formation of alcohols with a rearranged structure was used as a test for the M+-SN1 mechanism of hydrolysis, and the increase in the accumulation rate of RNO2 with increase in the concentration of NO2- and silver complexes was used as a test for the M+-SN2 mechanism of substitution of iodide by a nitrite ion.It was established that the rate constants vary in the order CH3I +-SN1 paths and CH3I (CH3)2CHCH2I >> (CH3)3CCH2I for the M+-SN2 paths.

Tertiary amines are more effective than primary and secondary amines which are more effective than oxyanions toward proton abstraction from nitroethane.The four homologous series of bases give rise to catalytic rate constants for nitroethane ionization that fall on three Broensted plots: for tertiary amines β=0.45, for primary and secondary amines β=0.60, and for oxyanions β=0.71.The increase in the Broensted β value with decreasing reactivity is in accord with the reactivity-selectivity principle.In nitroethane ionization a tertiary amine with conjugate acid of pKa=10.0 is 13-fold and one of pKa=6.2 is 130-fold more reactive than an oxyanion with a conjugate acid of the same pKa.These are much smaller rate ratios than were observed in the enolization of oxaloacetate where tertiary amines were found to be 800-fold and 2200-fold more reactive than oxyanions of pKa=10.0 and 6.2, respectively, giving further support to the previously proposed nucleophilic addition-elimination mechanism for tertiary amine catalyzed enolization of oxaloacetic acid.The greater reactivity of tertiary amines compared to oxyanions is ascribed to energy-lowering and energy-raising electrostatic interactions between the catalyst and the anionic charge developing on the substrate in the transition state.With primary and secondary amines the degree of transition-state electrostatic stabilization is decreased by solvation.Electrostatic stabilization can also be affected by certain functional groups in the amine.

The effects of oxygen on the product distribution from the surface-initiated reactions in flowing mixtures of H2O2, NO2, N2 and RH, where RH=ethane, propane, n-butane and n-pentane, at 298 K have been studied.In the absence of O2, the principal products are the corresponding nitroalkane, alkyl nitrite and alkyl nitrate.In the presence of sufficiently large concentrations of O2, the predominant product is the alkyl nitrate and the only other products of significance, in some cases, are the corresponding carbonyl compounds.The variation of the product yields with / gives values for the rate-constant ratios k8/(k3+k4) for reaction at both primary and secondary radical sites:.Possible mechanisms by which the products are formed are discussed.

When H2O2 vapour is added to an excess of NO2 in a flow system with ethane as the carrier gas in the presence of a boric-acid-coated surface at temperatures in the range 298-363 K, the organic products are niroethane, ethyl nitrate and smaller amounts of ethyl nitrite.On the basis of the initiating steps the total yield of nitro-compounds, extrapolated to =0, provides a direct measure of the H2O2 to OH conversion efficiency in step(1).This is shown to correspond to that indicated by the previously applied indirect method involving measurement of the variation of CO2 yields with the ratio / in H2O2+NO2+CO systems containing diethyl ether (S) as the internal kinetic calibrant.This efficiency does not change significantly throughout the above temperature range.The mechanism of formation of the nitrocompounds involves the following competitive steps: .Arguments are presented that step (8) may proceed by way of partial dissociation of chemically activated C2H5ONO molecules rather than by bimolecular O-abstraction route.A rate constant of k4=(1.3+/-0.2)xE10 dm3mol-1s-1 is obtained for the reaction at ambient temperature for M=C2H6 at a pressure of 40 kPa.

The principal products from the surface-initiated reactions in flowing mixtures of H2O2, NO2,N2 and RH, where RH=ethane, propane, n-butane and n-pentane, have been identified as the nitroalkane, alkyl nitrite and alkyl nitrate.The product yields have been measured; in the case of propane the variation of the yields with total gas pressure has also been studied.Values have been obtained for the relative rates of primary and secondary H-atom abstraction from each alkane by OH and for the rate-constant ratios k3/k4 and k5/k6 at 298 K:.The trends in the product yields with the variation of pressure and change of R indicate that RO radicals are produced via reactions (4)-(6) rather than by a single-step reaction of R with NO2.

Absolute rate constants have been measured for the .CH3 radical addition to the aci-anions of nitromethane, nitroethane, 1-nitropropane, and 2-nitropropane.The respective values of (1.35 +/- 0.2) * 1E8, (1.60 +/- 0.3) * 1E7, (1.35 +/- 0.3) * 1E7, and (2.35 +/- 0.5) * 1E6 dm3 mol-1 s-1 indicate a nucleophilic character of the methyl radical.From Taft's relationship on the inductive substituent effect, ρ* + 8.9 is derived.The optical absorption spectra of the methyl radical adducts, R1R2CH3NO2.-, are characterized by λmax. 270 nm and extinction coefficients of (2.8-3.0) * 1E3 dm3 mol-1 cm-1.

The type of radical detected by esr when first-formed short-lived radicals are generated by photolytic, radiolytic, or flow techniques in the presence of nitromethane is shown to depend upon the nature and structure of the transient radical and on the pH.Thus electron-donating radicals may react with CH3NO2 itself under certain conditions to give rise to CH3NO2-. and the alkoxy nitroxides CH3N(OR)O..At higher pH, a wide variety of radicals (X) react very readily with the aci-anion CH2:NO2- to give adducts XCH2NO2-. (and, from radicals capable of one-electron transfer, O2NCH2CH2NO2-.).Structural characteristics of adducts XCH2N O2-. are described and it is shown how radicals which are normally undetectable in fluid solution can be trapped and recognized in this way.Mechanistic pathways diagnosed with this trap (involving, e.g. alkoxyl radicals, aroyloxy radicals, aromatic carboxylate cation-radicals) are exemplified.

When H2O2 vapour and NO2 are mixed in an ethane carrier in a flow system in the presence of a boric acid-coated surface, ethyl nitrate, nitroethane, and some ethyl nitrite are synthesized; a mechanism is advanced in which OH* and C2H5* radicals are the intermediates.

Stannic chloride is removed from organic solvent-based waste streams by precipitating the salt as a dimethyl sulfoxide complex.