Synthesis of Amurensin H, a New Resveratrol Dimer from the Roots of Vitis Amurensis

Amurensin H(1) is a new resveratrol dimer isolated from the roots of Vitis amurensis Rupr. Its structure was determined by spectroscopic methods. II was synthesized from resveratrol with an oxidative coupling reaction as a key step.

Novel Method for Preparing a Carbon Nanotube-Supported Cobalt Catalyst for Fischer–Tropsch Synthesis:Hydrogen Dielectric-Barrier Discharge Plasma

Hydrogen dielectric-barrier discharge(H_2-DBD)plasma was successfully used to prepare carbon nanotubes(CNTs)-supported cobalt(Co) catalyst.The H_2-DBD plasma treatment simultaneously decomposed and reduced the cobalt precursor at a lower temperature and in a shorter time than the conventional method(calcination and hydrogen reduction).It is considered that the H_2-DBD plasma method can remarkably decrease the amount of energy input compared to traditional methods used to prepare the Co-based catalyst in Fischer-Tropsch synthesis(FTS).Results showed that the Co catalyst prepared by H_2-DBD plasma had an equivalent catalytic performance for FTS as that prepared using the conventional method in calcination and hydrogen reduction,thereby determining that H_2-DBD plasma was an effective alternative treatment for preparing the Co/CNTs catalyst for FTS.This technology will provide a new strategy for preparing catalysts in other catalysis processes.

A New Method for the Synthesis of Selenium Nanoparticles and the Application to Construction of H_2O_2 Biosensor

The well-distributed, stable selenium nanoparticles (10 nm) with good adhesive ability and biocompatibility were successfully synthesized by using the template of chitosan cross-linked with glutaradehyde. The resulting selenium nanoparticles were used as a new carrier for horseradish peroxidase to construct H2O2 biosensors with good performances.

Autopilot Control Synthesis for Path Tracking Maneuvers of Underwater Vehicles

This paper is concerned with the robust control synthesis of autonomous underwater vehicle （AUV） for general path following maneuvers. First, we present maneuvering kinematics and vehicle dynamics in a unified framework. Based on H∞ loop-shaping procedure, the 2-DOF autopilot controller has been presented to enhance stability and path tracking. By use of model reduction, the high-order control system is reduced to one with reasonable order, and further the scaled low-order controller has been analyzed in both the frequency and the time domains. Finally, it is shown that the autopilot control system provides robust performance and stability against prescribed levels of uncertainty.

Synthesis of 2, 6 Bis(1′-Phenyl- 3′- Methyl-5′-Oxopyrazole- 4′) Pyridinediacyl and Its Solid Liquid Extraction Behavior for Ce(Ⅲ)

diketone type chelating ligands have high coordinative activity and selectivity, and are widely applied in analytical chemistry. In order to obtain profounder understanding to the properties of bis(4 acylpyrazolone 5), A new 4 acylpyrazol 5 one derivative (H 2BPMPP) was syntheszed, which contains a heterocyclic ring between two 1 phenyl 3 methyl 4 acylpyrazol 5 one rings. The new compound was characterized by element analyses, UV, IR and 1H NMR spectra. The equilibrium of the keto enol tautomerism was studied. The results show that a lower dielectric constant of solvent favors the enol form which has a higher λ max . Due to special merits of paraffin wax, the solid liquid extraction behavior of Ce(Ⅲ) with molten paraffin wax as a diluent was also investigated at higher temperature. The value of the pH 1/2 was 3.19 and the value of log K ex was 3.467. The chemical composition of the complex was obtained by the slope analysis method.

Hydrothermal Synthesis of H_3PW_(12)O_(40)/TiO_2 Nanometer Photocatalyst and Its Catalytic Performance for Methyl Orange

H3PW12O40/TiO2 nanometer photocatalyst was prepared by one step hydrothermal synthesis from H3PW12O40·nH20 and Ti（OBu）4, simultaneously realizing the load and modification of H3PW12O40. The catalyst was characterized by Fourier transform infrared spectroscopy（FTIR）, powder X-ray diffraction（XRD）, nitrogen adsorp- tion-desorption analysis and scanning electron microscopy（SEM）. The results show that the catalyst is Keggin struc- ture and crystallized in anatase structure, the diameter and specific area of the prepared catalyst are 3.8 nm and 177.9 m^2/g, respectively, and its dispersity is better. The photocatalytic properties were compared for TiO2H3PW12O40/TiO2 prepared by impregnation and H3PW12O40/TiO2 prepared by hydrothermal method with methyl orange as a probe. The effects of H3PW12O40 loadings, crystallization method, initial pH and concentration of dye solution on the degradation of methyl orange were investigated.

Strontium chloride-catalyzed one-pot synthesis of 4(3H)-quinazolinones under solvent-free conditions

Strontium chloride was used as an efficient and recyclable catalyst in one-pot condensation of anthranilic acid, ortho esters and amines leading to the formation of 4（3H）-quinazolinone derivatives in good yields at room temperature under solvent-free conditions.

Synthesis, Bioactivity and Crystal Structure Analysis of 2-(Benzo[d]isothiazol-3-yloxy)-N-(3-cyano-1-(4-fluorophenyl)-1H-pyrazol-5-yl) Acetamide

A novel benzisothiazolin-3-one derivative, 2-（benzo[d]isothiazol-3-yloxy）-N-（3- cyano-l-（4-fluorophenyl）-lH-pyrazol-5-yl） acetamide （8）, was synthesized from the initial compound benzo[d]isothiazol-3（2H）-one （BIT） 1 and 4-fluoroaniline 3. The structure of the target compound 8 was determined by elemental analyses, IR and 1H NMR. The single crystals of intermediate compound 6 and the target compound 8 were obtained and determined by X-ray diffraction analysis. The preliminary biological activity was also evaluated and the results showed tile target compound exhibited a good anti-microbial activity.

Synthesis of (1H)-3,4-Dihydropyrrolo[2,1-c][1,4]oxazin-1-one Derivatives

In search of new anti-inflammatory and analgesic agents, (1H)-3,4-dihydro- pyrrolo [2,1-c][1,4]oxazin-1-one (3) and its acyl derivatives were designed and prepared. Compound 3 was prepared by treatment of methyl 1-(2-bromoethyl) pyrrole-2-carboxylate with silver oxide and its derivatives were obtained by Friedel-Craftes reaction. Nine of 6-acyl derivatives of compound 3 were prepared.

Role of size and pretreatment of Pd particles on their behaviour in the direct synthesis of H_2O_2

Two families of catalysts, based on Pd nanoparticles supported on ceramic asymmetric tubular alumina membranes, are studies in the direct synthesis of H2O2. They are prepared by depositing Pd in two ways：（i） reduction with N2H4 in an ultrasonic bath and（ii） by impregnation-deposition. The first preparation leads to larger particles, with average size of around 11 nm, while the second preparation leads to smaller particles, with average size around 4 nm. The catalytic membranes were tested as prepared, after thermal treatment in air and after further pre-reduction with H2 in mild（100 ℃） conditions. Samples were characterized by TEM, CO-chemisorption monitored by DRIFTS method and TPR, while catalytic tests have been performed in a semi-batch recirculation membrane reactor. Experimental catalytic results were analysed using two kinetics models to derive the reaction constants for the parallel and consecutive reactions of the kinetic network. Smaller particles of Pd show lower selectivity due to the higher rate of parallel combustion, even if the better dispersion of Pd and thus higher metal surface area in the sample lead to a productivity in H2O2 similar or even higher than the sample with the larger Pd particles. Independently on the presence of smaller or larger Pd nanoparticles, an oxidation treatment leads to a significant enhancement in the productivity, although the catalyst progressively reduces during the catalytic process. The inhibition of the parallel combustion reaction（to water） induced from the calcination treatment remains after the in-situ reduction of the oxidized Pd species formed during the pre-treatment.This is likely due to the elimination of defect sites which dissociatively activate oxygen, and tentatively attributed to Pd sites able to give three- and four-fold coordination of CO.

Synthesis and Crystal Structure of 2-Ethoxy-3-n-butyl-benzofuro [2,3-d]pyrimidin-4(3H)-one

The crystal structure of the new title compound 2-ethoxy-3-n-butyl- benzofuro[2,3d]pyrimidin-4（3H）-one （C16H18N2O3, Mr = 286.32） has been prepared and determined by singlecrystal X-ray diffraction. The crystal is of monoclinic, space group P21/c with a = 13.7167（14）, b = 13.113（1）, c = 8.378（1） A, β = 98.992（2）^o, V = 1488.4（3） A^3, Z = 4, Dc = 1.278, F（000） = 608, μ = 0.089 mm^-1, MoKa radiation （2 = 0.71073）, R = 0.0498, wR = 0.1238 for 2336 observed reflections with I 〉 2σ（I）. X-ray diffraction analysis reveals that all ring atoms in the benzo[4, 5]furo [2,3-d] pyrimi- dinone moieties are almost coplanar.

Co-CeO_2/SiO_2 Fischer-Tropsch Synthesis Catalyst

A series of Co (10.7 wt. %)-CeO2/SiO2 catalysts with various cerium contents was prepared and evaluated. The optimized ceria-promoted catalyst exhibits good activity, high selectivity towards long chain hydrocarbons, and excellent stability. The promotion mechanism of ceria was investigated using X-ray diffraction (XRD), temperature programmed reduction (TPR), H2 temperature programmed surface reaction (H2-TPSR) and transient response technique. It is suggested that the improved catalytic performance of the catalyst modified by ceria be attributed to (1) the improvement in the dispersion of metallic cobalt and the amount of active sites for Fischer-Tropsch Synthesis (FTS), leading to an increased concentration of surface active carbon species and high selectivity towards long chain hydrocarbons; (2) the inhibition of disproportionation of CO and the removal of inactive surface carbon species.

Synthesis, Crystal Structure and Antibacterial Activities of 3-[3-Methyl-(2-thienyl)methyl- enehydrazinocarbonyl]-(1H)-1,2,4-triazole

The title compound, C9H9N5OS, was synthesized by the reaction of 3-（1H）-1,2,4 -triazole hydrazine with 3-methyl-2-thiophenecarboxaldehyde in ethanol. The single crystal structure has been determined by X-ray diffraction analysis. The crystal belongs to monoclinic system, space group P2 1/n with a = 9.5550（10）, b = 11.9847（12）, c = 10.1074（11） A,β= 112.995（2）° V= 1065.47（19） A^3, Z = 4,μ = 0.290 mm^-1, Mr= 235.27, Dc = 1.467 g/cm^3 and F（000） = 488. The structure was solved by direct methods and refined to R = 0.0449. The crystal structure involves intermolecular hydrogen bonds of N-H…O and N-H…N as well as intramolecular hydrogen bond of N-H…N. Its biological activity has also been determined showing this type of compounds has certain antibacterial activity.

The Synthesis of 3-(2'-Hydroxybutyl) isobenzofuran-1 (3H)-one

The synthesis of 3-(2'-hydroxybutyl）isobenzofuran-1(3H)-onel from phthalicanhydride via the intermediate 3-(2'-oxoethyl) isobenzofuran-1(3H)-one 6 was described．

NEW HETEROCYCLIC SYSTEM SYNTHESIS H THE REACTION OF 2,3-DIHYDRO-1,5-BENZOTHIAZEPINES WITH DICHLOROCARBENE

The reaction of two series of 2,3-dihydro-1,5-henzothiazepines Ⅰ with dichloro- carbene,gave azirino[2,1-d][1,5]benzothiazepines Ⅷ,azirino[2,1-e][1,6]benzothiazocines Ⅸ, pyrrolo[2,1-b][1,3]benzothiazoles Ⅹ,substituted-cyclopropanes Ⅺ and 2H-1,4-benzothiazin-2-ones Ⅻ.The structures of these products were confirmed by the analytical and spectral data.Compound Ⅷ and Ⅸ are two new ring systems.

A facile one-pot synthesis of new thieno-[2,3-d]pyrimidine-2,4(1H,3H)-dione derivatives

A facile one-pot synthesis of new 3-arylthieno[2,3-d]pyrimidine-2,4（1H,3H）-diones via base-catalyzed cyclocondensation of ethyl 2-amino-4,5-dimethylthiophene-3-carboxylate with aryl isocyanates is described.

Synthesis, Bioactivity, and Crystal Structure Analysis of 2-(3-Oxobenzo[d]isothiazol-2(3H)-yl)ethyl Benzoates

Fifteen novel 2-（3-oxobenzo[d]isothiazol-2（3H）-yl）ethyl benzoates were synthesi- zed by the condensation of 2-（2-hydroxyethyl）benzo[d]isothiazol-3（2H）-one with substituted benzoic acids in dichloromethane. All the compounds were characterized by elemental analysis, IR, ESI-MS and 1H NMR. The crystal structures for 2-（2-hydroxyethyl）benzo[d]isothiazol-3（2H）-one （2） and 2-（3-oxobenzo[d]isothiazol-2（3H）-yl）ethyl 2-methoxybenzoate （30） have been determined by X-ray crystal structure analysis. Compound 2 （C9H9NO2S） crystallizes in the monoclinic system, space group Pn with a = 10.552（3）, b = 7.849（2）, c = 10.765（4） A, β = 103.128（4）°, V= 868.3（5） A3, Mr = 195.24, Dc = 1.493 Mg.m-3, μ = 0.33 mm-1, F（000） = 408, Z = 4, R= 0.0314 and wR= 0.0628. Compound 30 （C17H15NO4S） crystallizes in the triclinic system, space group P1 with a = 8.028（2）, b = 9.300（2）, c = 10.430（3）A, V= 752.1（3）A3, Mr = 329.36, D,= 1.454 Mg.m-3, p = 0.24 mm-1, F（000） = 344, Z = 2, R = 0.0377 and wR = 0.0904. The preliminary biological test indicated that the title compounds show better growth inhibitory activity against the gram-positive bacteria than the gram-negative bacteria.