Ultrasound-promoted solvent-free aza-Michael addition of p-toluenesulfonamide to fumaric esters by potassium carbonate: Synthesis of p-toluenesulfonamide derivatives

An efficient, mild, inexpensive and eco-friendly protocol for the synthesis of p-toluenesulfonamide derivatives by aza-Michael addition reaction of p-toluenesulfonamide to fumaric esters using potassium carbonate under ultrasound irradiation was developed. This method is simple, convenient and the desired compounds are produced in good to excellent yield. The bulkiness of alkoxy group (–OR) of fumaric esters did not affect significantly on the yields and reaction times. This reaction worked well on linear and nonlinear alkyl fumarates. The reaction, surprisingly, was not successful on methyl fumarate. In this case methyl fumarate has been hydrolyzed to fumaric acid under reaction conditions.     

Theoretical investigation of scattering of an atomic projectile confined in a harmonic surface potential

In this paper, scattering of a projectile atomic gas confined in an atomic harmonic surface is studied using the Lippmann–Schwinger. The nonlocal separable potential of rank one has been assumed between the projectile gas and surface, because this potential is useful to investigate the few-body systems. The analytical solution of Lippmann–Schwinger equation has been derived, and the scattering properties including transition and scattering matrices, phase shift, scattering amplitude and time delay are calculated analytically as a function of incident atomic gas energies.     

Use of the velocity of sound in predicting the PVT relations

Thermodynamic properties of fluids are generally calculated from the PVT relations through equations of state. The majority of existing equations of state require the critical properties or intermolecular potential energy parameters as their input data. In many cases, such properties are neither available nor they can be accurately estimated.

One accessible and accurately measurable property of substances is the velocity of sound. In this report a method is introduced through which one can predict the PVT behavior of fluids using the velocity of sound data. A general mathematical relationship,

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expressing the velocity of sound, c, in terms of the hard-core velocity of sound, c_hs, and thermodynamic properties is derived. One may use this equation to extract PVT data from cVT data, or vice versa. As an example the virial coefficients, the Lennard-Jones intermolecular potential parameters, and the constants of the van der Waals equation of state for a number of pure fluids are calculated using the velocity of sound data. Utility of this method is particularly attractive for such compounds as heavy hydrocarbons, unstable fluids, and newly designed molecules for which intermolecular parameters and critical properties are not available.     

Synthesis,characterization, and free radical polymerization of new acrylamide-based monomer containing a 1<Emphasis Type="Italic">H</Emphasis>-tetrazole ring: Thermal investigation and derivatization of the homopolymer

N-[4-(1H-Tetrazol-5-yloxy)phenyl]acrylamide was synthesized and subjected to homopolymerization under radical initiation. The structure of the monomer and homopolymer was characterized by elemental analyses (C, H, N), FT-IR, and ¹³C and ¹H NMR data. Thermal behavior of the homopolymer was studied by differential scanning calorimetry and thermogravimetric analysis. The tetrazole ring in the homopolymer was converted into imidoyl azide derivatives via reactions with cyanogen bromide, p-toluenesulfonyl chloride, and trifluoro-methanesulfonyl chloride. Published in Russian in Zhurnal Organicheskoi Khimii, 2007, Vol. 43, No. 6, pp. 890–897. The text was submitted by the authors in English.     

Aqueous Media Oxidation of Alcohols with Ammonium Persulfate

Oxidation of series of various primary and secondary alcohols to corresponding carbonyl compounds with ammonium persulfate in aqueous media was described. No over oxidation of primary alcohols to carboxylic acids and secondary alcohols to esters was observed. Under such conditions benzoin was converted to benzoic acid.     

Transesterification Reaction of Dimethyl Terephthalate by 2-Ethylhexanol in the Presence of Heterogeneous Catalysts under Solvent-free Condition

In this study, the synthesis of bis-（2-ethylhexyl） terephthalate, via the transesterification reaction of dimethyl terephthalate （DMT） by 2-ethylhexanol in the presence of different heterogeneous catalysts, such as Pb（OAc）2·3H2O, Cd（OAc）2·2H2O, Zn（OAc）2·2H2O, Hg（OAc）2·Ca（OAc）2·H2O, Cu（OAc）2·H2O, NaOAc, CaCO3, CaO, ZnSO4·7H2O, and sulfated zirconia, has been investigated. The reactivity of the catalysts in the reaction progress has been studied and compared. It was found that, hydrated cadmium acetate and sulfated zirconia were reactive catalysts to this reaction. The extent of transesterification of methyl ester groups reached up to 93% and 85.6% using these catalysts, respectively.     

Reliability and Efficiency of Generalized Rumor Spreading Model on Complex Social Networks

We introduce the generalized rumor spreading model and investigate some properties of this model on different complex social networks. Despite pervious rumor models that both the spreader-spreader (SS) and the spreader-stifler (SR) interactions have the same rate α, we define α⁽¹⁾ and α⁽²⁾ for SS and SR interactions, respectively. The effect of variation of α⁽¹⁾ and α⁽²⁾ on the final density of stiflers is investigated. Furthermore, the influence of the topological structure of the network in rumor spreading is studied by analyzing the behavior of several global parameters such as reliability and efficiency. Our results show that while networks with homogeneous connectivity patterns reach a higher reliability, scale-free topologies need a less time to reach a steady state with respect the rumor.     

Synthesis of organo soluble aromatic poly(amide-imide)s based on 2-(5-(3,5-dinitrophenyl)-1,3,4-oxadiazole-2-yl)pyridine in an ionic liquid

In this work,the syntheses of new thermally stable poly(amide-imide)s with pendant 2-pyridyl-1,3,4-oxadiazole units in n-butyl methyl imidazolium bromide as reaction media have been reported.A new dicarboxylic acid has been derived from the reaction of diamine,2-(5-(3,5-diaminophenyl)-1,3,4-oxadiazole-2-yl)pyridine(POBD),and trimellitic acid anhydride.Polymers were prepared from the reaction of the diimide-diacid(DIDA) and different aromatic diamines in butyl methyl imidazolium bromide,[bmim][Br],in the ...     

A method for the low-level (ng/g) determination of perfluorooctanoate in carpet by LC-MS-MS using matrix extracted standards

Fluorotelomer-based acrylic polymers are applied to the surface of carpet to impart oil, stain, and water repellence properties. Concerns that fluorotelomer-based polymers are a possible source of "low level" exposure to humans, coupled with their widespread use have prompted the need to develop a method to detect and measure perfluorooctanoate (PFO) in carpet. A liquid chromatography tandem mass spectrometry method for the determination of PFO in carpet using a dual labeled 13C-perfluoroctanoic acid (13C-PFOA) internal standard is successfully developed and validated. Levels of PFO are determined using a gradient, reversed-phase high-performance liquid chromatography (HPLC) method with acetic acid acidified water-methanol, separated on a 50 mm Phenomenex Synergi Polar RP column. Ions monitored are 413 (parent) and 369 (daughter) for PFO and 415 (parent) and 370 (daughter) for dual labeled 13C-PFOA internal standard. Accuracy and precision over three days for 5 to 900 ng/g PFO in carpet ranged from 2.4% to 7.6% and 3.7% to 14.1%, respectively. Overall extraction efficiency for samples (n=30) fortified with 13C-PFOA at 20 ng/g and perfluorooctanoic acid (PFOA) at 5, 50, and 500 ng/g is 98.9%+/-8.1%. Specificity of the method was evaluated with two different carpet samples.