43,349 research outputs found
Interaction of some extreme-pressure type lubricating compounds with an iron surface
An iron surface was exposed to the extreme-pressure type lubricant benzyl chloride, dichlorophenyl phosphine, dichlorophenyl phosphine sulfide, ophenyl phosphine oxide. Iron, in the sputter-cleaned state, was exposed to these materials statically and during dynamic friction experiments. With benzyl chloride only chlorine adsorbed to the surface, and with dichlorophenyl phosphine no adsorption occurred, while the addition of sulfur to that same molecular structure resulted in the promotion of carbon and chlorine adsorption. substitution of oxygen for sulfur in the dichlorobenzyl phosphine molecule resulted in carbon, chlorine, and oxygen adsorption. With none of the phosphorus containing molecules was phosphorus detected on the surface. Sliding in an atmosphere of benzyl chloride promoted adsorption of chlorine to the iron surface. Increases in load resulted in a decrease in the surface concentration of iron chloride
Electrocarboxylation in supercritical CO2 and CO2-expanded liquids
In this study, the electrocarboxylation of benzyl chloride in pressurized CO2, or pressurized mixtures of dimethylformamide (DMF) and CO2, was investigated in order to synthesize phenylacetic acid. A stainless steel cathode was used as the working electrode, whereas a sacrificial massive magnesium rod or a platinized platinum grid was used as the anode, tetrabutylammonium perchlorate (TBAP) or tetrakis(decyl)ammonium tetraphenylborate (TDATPhB) being the supporting electrolyte. The electrocarboxylation was carried out at 40 ◦C, at operating pressures of 1, 6, 7, 8, 9 and 12MPa, using current densities ranging from 0.1 to 150mAcm−2. It was found that a small amount of DMF was necessary to ensure the solubility of the supporting electrolyte, to obtain sufficient electrical conductivity of the medium. The best resultswere obtained using the magnesium sacrificial anode, at 6MPa. After consumption of the theoretical amount of electrical current (2F mol−1), 65.7% benzyl chloride conversion was reached, together with an 82.4% phenylacetic acid selectivity and a 54.2% faradaic yield. Detected by-productswere toluene, bibenzyle, benzyl alcohol and benzaldehyde
Synthesis of BIS-(p-Chlorobenzyl) Sulphide Using H2S and TBMAC Polymer Bound as Phase Transfer Catalyst
The aim of this project is the utilization of Hydrogen Sulphide (H2S) in the synthesis of Dibenzyl Chloro Sulphide (DCBS) and ChloroBenzyl Mercaptan (CBM). This is done by the absorption of H2S in methyl Diethanolamine first and then reaction of this H2S rich methyl Diethanolamine with Chloro Benzyl Chloride for the formation of DBCS and CBM. The reaction of methyl Di ethanolamine and Chloro Benzyl Chloride is very difficult as they are two different phases, So the phase transfer catalyst has been used to carry out this reaction. The TBMAC Polymer bound has been chosen as the PTC as it is solid and reusable. The overall objective of this project is to maximize the conversion of Chloro Benzyl Chloride and maximize the selectivity of DBCS. In this project Chloro Benzyl Chloride has been used along with Toluene as a solvent.It also includes study about sources of hydrogen sulfide, need for removal, recovery and PTC study. Parameters chosen for maximizing conversion and selectivity are Reaction time, catalyst loading, stirring speed, temperature and Chloro Benzyl Chloride concentration
Reaction kinetics for the synthesis of benzyl benzoate from benzyl chloride and the triethylamine salt of benzoic acid
The reaction kinetics for the synthesis of benzyl benzoate from benzyl chloride and the triethylamine salt of benzoic acid has been studied over the temperature range of 70-105°C and a mole ratio of benzyl chloride to triethylamine of 0.5 - 10.0.
A reaction mechanism which is consistent with the experimental data has been derived. The experimental data was analyzed by means of the integral method of analysis. The temperature dependency of the reaction was determined from Arrhenius\u27 Law and the activation energy was calculated to be 15,064 cal/g-mole. An empirical equation which explains the effects of the reactant mole ratio was derived.
The reaction under study turned out to be a pseudo first order reaction dependent upon the concentration of benzyl chloride. The observed first order reaction rate constant is a function of the initial mole ratio of triethylamine to benzyl chloride. The reaction occurs mainly by the SN2 mechanism.
The reaction kinetics studies should provide a useful tool in the evaluation of benzyl benzoate manufacturing processes
The kinetics and hepatotoxicity of benzyl chloride vapor in rats
Male Sprague Dawley rats (250g) were exposed to benzyl chloride vapor at a concentration of 220 ppm for 6 hours. During inhalation, the blood benzyl chloride concentration increased to reach a steady state level of 9-10 ug/ml between 4 and 6 hours of exposure. A small concentration of benzyl chloride (0.86 ug/ml) was present in the blood four hours after the termination of exposure. The absorption half life was 0.53 hours (0.39-0.81) and the elimination half life was l.12 hour (0.93-l.40).
The absorbed benzyl chloride was largely retained in the blood and some of it (0.22 ug/g) was sequestered into adipose tissue. Benzyl chloride was not detected in the brain, liver, lungs, pancreas and testis. A new HPLC method was used to separate benzylmercapturic acid in the rat blood. In the first hour of exposure, an amount equal to the parent compound was metabolized into benzylmercapturic acid. By 4 hours post exposure, the concentration of benzylmercapturic acid was 25% of the parent compound detected in blood. Liver and kidney glutathione levels in the treated rats were depleted to 13.5 and 46% of the control values, respectively. Liver appears to be the major source of the thiol group in benzylmercapturic acid, while kidney is the secondary source. Benzyl chloride is heptatoxic and causes microvesicular fatty change, inflammation and glycogen depletion in the liver, in the absence of lipid peroxidation in vivo
Cloud point extraction of phenol and benzyl alcohol from aqueous stream
Two-aqueous phase extraction of phenol and benzyl alcohol as a solute from their aqueous solutions was investigated using polyethoxylated alcohols (CiEj) as a biodegradable non-ionic surfactant. First, the phase diagrams of the binary systems, water–surfactant (Oxo-C10E3 and Oxo-
C13E9), and the pseudo-binary systems, water–surfactant with a constant concentration of solute was determined. The effect of sodium chloride and sodium sulphate on water–surfactant systems were studied. According to the given surfactants concentrations and temperatures, the extraction
results were expressed by the following four parameters, percentage of extracted solute, E, which reached 95 and 90% for phenol and benzyl alcohol, respectively, residual concentrations of solute, Xs,w, and the surfactant, Xt,w, in the dilute phase and volume fraction of the coacervate
at the equilibrium condition, φc. The values of these parameters were determined by an analyzing central composite designs. After the first extraction process, phenol and benzyl alcohol concentrations in the effluent were reduced about ten times for the first and four times for the second, correspondingly
Stability and activity of Zn/MCM-41 materials in toluene alkylation: Microwave irradiation vs continuous flow
Zn/MCM-41 mesoporous materials have been prepared via classic wet impregnation, employing zinc nitrate as precursor and tested for activity and stability in the Friedel-Crafts alkylation of toluene with benzyl chloride under microwave irradiation and continuous flow. The modified materials were characterized by means of a number of analytical techniques, and surface and textural properties were thoroughly checked. Materials containing the highest Zn loading (15 wt %) provided full conversion after 5 minutes reaction under microwave irradiation (300 W, 120 °C). Materials were proved to be stable and reusable for several cycles with an optimum performance under continuous flow conditions.Fil: Carraro, Paola María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigación y Tecnología Química. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación y Tecnología Química; ArgentinaFil: Goldani, Bruna S.. Universidade Federal de Pelotas; BrasilFil: Alves, Diego. Universidade Federal de Pelotas; BrasilFil: Sathicq, Angel Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Ciencias Aplicadas; ArgentinaFil: Eimer, Griselda Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigación y Tecnología Química. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación y Tecnología Química; ArgentinaFil: Romanelli, Gustavo Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Ciencias Aplicadas; ArgentinaFil: Luque, Rafael. Universidad de Córdoba; España. Rudn University; Rusi
Reaction of selected carbohydrate aldehydes with benzylmagnesium halides: benzyl versus o-tolyl rearrangement
The Grignard reaction of 2,3-O-isopropylidene-alpha-D-lyxo-pentodialdo-1,4-furanoside and benzylmagnesium chloride (or bromide) afforded a non-separable mixture of diastereomeric benzyl carbinols and diastereomeric o-tolyl carbinols. The latter resulted from an unexpected benzyl to o-tolyl rearrangement. The proportion of benzyl versus o-tolyl derivatives depended on the reaction conditions. Benzylmagnesium chloride afforded predominantly o-tolyl carbinols while the application of benzylmagnesium bromide led preferably to the o-tolyl carbinols only when used in excess or at higher temperatures. The structures of the benzyl and o-tolyl derivatives were confirmed unambiguously by NMR spectral data and X-ray crystallographic analysis of their 5-ketone analogues obtained by oxidation of the corresponding mixture of diastereomeric carbinols. A possible mechanism for the Grignard reaction leading to the benzyl -> o-tolyl rearrangement is also proposed
Intramolecular C−H Activation of a Bisphenolate(benzene)-Ligated Titanium Dibenzyl Complex. Competing Pathways Involving α-Hydrogen Abstraction and σ-Bond Metathesis
A titanium dibenzyl complex featuring a ligand with two phenolates linked by a benzene-1,3-diyl group was found to undergo thermal decomposition to give toluene and a cyclometalated dimeric complex. The thermal decomposition followed first-order kinetics and was studied at a number of temperatures to determine the activation parameters (ΔH‡ = 27.2(5) kcal/mol and ΔS‡ = −6.2(14) cal/(mol K)). Deuterated isotopologues were synthesized to measure the kinetic isotope effects. The complexes with deuterium in the benzyl methylene positions decomposed more slowly than the protio analogues. Isotopologues of toluene with multiple deuteration positions were observed in the product mixtures. These data are consistent with competing α-abstraction and σ-bond metathesis
Enantioselective synthesis of (+)-petromyroxol, enabled by rhodium-catalyzed denitrogenation and rearrangement of a 1-sulfonyl-1,2,3-triazole
Petromyroxol is a non-racemic mixture of enantiomeric oxylipids isolated from water conditioned with larval sea lamprey. The (+)-antipode exhibits interesting biological properties but only 1 mg was isolated from >100000 L of water. Recently, transition metal-catalyzed denitrogenation of 1-sulfonyl-1,2,3-triazoles has emerged as a powerful strategy for the synthesis of value-added products, including efficient diastereocontrolled construction of tetrahydrofurans. This methodology enabled the rapid development of the first synthesis of (+)-petromyroxol in 9 steps and 20% overall yield from a readily accessible starting material
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