Advanced Materials Research Vols. 781-784

Abstract: Deep desulfurization via π-complexation adsorption is a promising method for the purification of diesel. Activated carbon (AC) with copper and palladium deposited on their surfaces were investigated as adsorbents to remove benzothiophene (BT) from model diesel fuel. The adsorbents were prepared by ultrasonic-assisted impregnation and characterized using X-ray diffraction (XRD) and Scanning Electron Microscopy with Energy-dispersive X-ray Spectroscopy (SEM/EDS). The adsorption isotherms of BT were also investigated.

Abstract: A piperidine-functionalized poly (ethylene glycol) bridged dicationic ionic liquid PEG₈₀₀-DPIL(Cl) was synthesized and applied to catalyze the four-component Hantzsch reaction under solvent-free conditions and afford hydroquinolines with high to excellent yields. PEG₈₀₀-DPIL(Cl) could be recovered by simple workup and recycled for at least eight times without obvious activity loss.

Abstract: The decarboxylation mechanism of oxaloacetic acid aided with ethylenediamine or without any catalyst is investigated employing Density Functional Theory (DFT). DFT calculations for both the gas phase and in water solution indicate a stepwise mechanism for each of the steps of the reactions. In the catalyzed mechanism, the dehydration of carbinolamine (IM1) is via a seven-membered ring transition structure (TS5), which is consistent with the structure proposed by Thalji, et al. The decarboxylation of the imine (IM6) is the rate determining step with an energy barrier of 16.46 kcal/mol, lower than the reaction without any catalysts or catalyzed with ions.

Abstract: Esterification of carboxylic acids and transesterification of β-ketoesters with alcohols have been developed by using catalytic amount of p-toluene sulfonic acid (PTSA) to afford the corresponding esters in good yields.

Abstract: The tri-n-octylmethyl-ammonium methyl carbonate was synthesized via a high pressure process with tri-n-octylamine(tri-C₈) and dimethyl carbonate(DMC) in the catalysis of tri-n-octylmethyl-ammonium bromine, and its chemical structure was confirmed using FTIR spectroscopic analysis. The influence of reactants molar ratio, reaction temperature, solvent, catalyst and reaction time on the quaternization reaction were examined, and the optimal conditions were that dimethyl carbonate(DMC):tri-n-octylamine(tri-C₈)=5.6:1(molar:molar), methanol:tri-n-octylamine (tri-C₈)=1:2 (volume:volume), catalysts 5% of the weight of reactant mixtures(materials fraction), reaction temperature 110°C and reaction time 8 h. Under the optimum conditions, the highest conversion rate of tri-n-octylamine(tri-C₈) could reach 99.57%. A type of SO₄^2- quaternary ammonium salt was prepared by the reaction between the product and H₂SO₄, and its properties on extracting vanadium in the feed solution from autoclave-soda leach solution of stone coal was researched, demonstrating that with 8% the type of SO₄^2- quaternary ammonium salt(QAS) and 5% sec-octyl alcohols dissolved in 87% sulphonated kerosene as extractant (volume fraction), the saturated loading capacity for V₂O₅ reaches 14.32 g/L.

Abstract: Polyethylene glycol-400 was used as phase transfer catalyst in reaction of dichloropyridine and sodium thiomethoxide to form 2-methylthiopyridine with a yield of 97.8%. Then 2-methylthiopyridine and sodium hypochlorite were added respectively to oxidize and bromize it to synthesis 2-Pyridyl tribromomethyl sulfone, with the purity of 99.6% and yield of 93.3%. Mass ratio of dichloropyridine versus polyethylene glycol-400 is 1:0.18, and molar ratio of dichloropyridine versus sodium thiomethoxide is 1:1.2. The optimum conditions to prepare sodium hypochlorite are a temperature at-5 to 0 °C, a molar ratio of bromine versus sodium hydroxide being 1:4. Proved optimum conditions to synthesis 2-pyridyl tribromomethyl sulfone are a temperature at (80±1)°C, reaction time for 5 hours and the molar ratio of 2-methylthiopyridine versus bromine being 1:6.58. Probable mechanism of synthetizing 2-methylthiopyridine was speculated, properties with structure of resultant substances were characterized by melting point apparatus, IR spectra and magnetic resonance spectrum.

Abstract: Butanone 1,2-propanediol ketal was synthesized by butanone and 1,2-propanediol as raw materials and sulfamic acid as catalyst. The effects of the mole ratio of raw materials agent, the dosage of the water-carrying agent and catalyst, reaction time on the product yield were discussed separately. Experimental results showed that sulfamic acid was a suitable catalyst for synthesizing of butanone 1,2-propanediol ketal. And the optimal reaction conditions are as follows: the mole ratio of butanone to 1,2-propanediol is 1:1.5, the amount of the catalyst is 2.2%, the water-carrying agent is 25ml, the reaction temperature is 358-378K and reaction time 3h. In this condition, the yield of production could reach 93.8%.

Abstract: In order to obtain the important liquid crystal intermediate with trifluoromethyl substitutent, Sonogashira coupling reaction was used to synthesize the compound. In this paper, the intermediate was synthesized by 4'-Iodo-4-pentyl-biphenyl and trimethyl silyl acetylene (TMSA) as raw materials. During the synthesis, the optimum reaction conditions were obtained, that the mol ratio of 4'-Iodo-4-pentyl-biphenyl and trimethyl silyl acetylene is 1:2, the reaction temperature is 30 oC, and the reaction time is 10 h.

Abstract: Cyclohexyl ferulate was prepared by direct sterification of ferulic acid and cyclohexanol as raw materials with sodium bisulfate supported by silica as a catalyst. The influences of some factors on the synthesis process were studied. The optimal reaction conditions based upon 0. 2 mol of ferulic acid were chosen that the molar ratio of cyclohexanol and ferulic acid was 10 : 1, the mass ratio of catalyst to reactants was 5%, refluing reaction time was 3.5 hours, et a1. The yield of the product reached 80%. The structure of the product was characterized by IR, 1H NMR and MS spectrum. The catalyst could be recycled and used for many times, which is friendly to the environment.

Abstract: Methodology has been sought towards 1,4-naphthoquinone bearing amino group and hydroxyl group in the quinonoid ring. In the first of these objectives, 2-Hydroxy-3-nitro-1,4-naphthoquinone was synthesized by two kinds of improved method giving moderate yield. Then treatment of 2-hydroxy-3-nitro-1,4-naphthoquinone with stannous chloride in aqueous medium afforded 2-hydroxy-3-amino-1,4-naphthoquinone. The chemical structure of the product obtained by the process of the present study was verified by IR and NMR.