Synthetic Ionophores. Part 17. Synthesis of Ether-Amine-Amide Based m-Cyclophanes: A Search for Pb2+ Selective Ionophores

m-Cyclophanes 3, 4, and 5 possessing two ether oxygen, two amide, one NH and a -system, an optimal combination of ligating sites for selective Pb²⁺ binding, have been synthesized by condensations of diethylenetriamine, 3,3-diaminodipropylamine and 1,3-diaminopropane with 1,3-bis(ethoxycarbonylmethoxy) benzene (6) formed by the PTC reaction of resorcinol and ethyl chloroacetate. Ionophores 3-5 induced cation extraction/transport could not be studied due to their insolubility in CHCl₃/CH₂Cl₂ and solubility in water, but ¹³CNMR titrations of 4 with metal ions point to its binding preferences for Ag⁺ and Pb²⁺ over alkali/alkaline earth cations.     

Influence of Pretreatment on the Interaction of Oxygen with Silver and the Catalytic Activity of Ag／SiO2 Catalysts for CO Selective Oxidation in H2

The interactions of oxygen with pre~reduced silver catalysts as well as their catalytic propertiesfor CO selective oxidation in H2 after oxygen pre-treatment are studied in this paper. It is found that the pretreatment exerts a strong influence on the activity and selectivity of the silver catalyst. A drop in activity and selectivity is observed after treating a pre-reduced catalyst with oxygen at low temperatures,whereas a converse result is obtained after an oxidizing treatment at high temperatures (T≥350℃). O2-TPD results show that surface oxygen species adsorbs on silver surface after the oxygen treatment at low temperatures. However, penetration of oxygen into the silver is enhanced by a high temperature treatment, meanwhile the surface oxygen species disappear. No other silver species except metallic silver are observed on all the catalysts by XRD, and the size of silver particle is not changed after the treatment with oxygen at low temperatures. The surface oxygen species formed by oxygen treatment can also be removed by hydrogen reduction. The strongly-adsorbed surface oxygen species prohibit the adsorption and diffusion of oxygen species in reaction gas on the surface of silver catalyst, causing the decrease in CO oxidation activity, in other words, it is important to obtain a clean silver surface for increasing the catalyst activity in CO removal from H2-rich feed gas. The differences in activity and selectivity due to the oxygen pretreatment at different temperatures axe discussed in terms of the changes in the surface/subsurface oxygen species of the silver particles.     

一个基于5-(3-氨基-吡啶-4-基)-间苯二羧酸和桨轮状[Cu2(COO)4]簇的rtl-金属有机骨架材料的合成及其CO2选择性吸附性质

利用新配体5-（3-氨基-吡啶-4-基）-间苯二羧酸（NH₂-H₂L₁）,我们成功设计、合成了一例氨基功能化的柱-层型rtl-MOF,SNNU-Bai65。与原型MOF（SYSU）对比,极性官能团氨基对孔表面的功能性修饰和对孔道的分割使得SNNU-Bai65经活化后展现出更好的CO₂/N₂和CO₂/CH₄的选择性CO₂吸附性能。     

Solid Phase Extraction and Spectrophotometric Determination of Silver with 2-(2-Quinolylazo)-5-diethylaminoaniline as Chromogenic Reagent

 A new chromogenic reagent, 2-(2-quinolylazo)-5-diethylaminoaniline(QADEAA), was synthesized. A highly sensitive, selective and rapid method for the determination of silver was developed. It is based on the rapid reaction of silver (I) with QADEAA and the solid phase extraction of colored chelate using reversed-phase separation cartridge. At pH 6.5 in the presence of sodium dodecyl sulfonate (SDS), QADEAA reacts with silver to form a violet chelate in a molar ratio of 1:2 (silver to QADEAA). This chelate was enriched by solid phase extraction. The retained chelate can be eluted from the cartridge with ethanol. In ethanol medium, the molar absorptivity of the chelate is 1.36×10⁵ L·mol⁻¹·cm⁻¹ at 590 nm. Beer’s law is obeyed in the range 0.01–0.6 μg L⁻¹. The relative standard deviation for eleven replicate samples of 0.01 μg L⁻¹ level is 1.9%. The detection limit reaches the 0.02 μg L⁻¹ level. This method shows satisfactory results when used for the determination of silver in water. Correspondence: Department of Chemistry, Yuxi Teacher’s College, Yuxi, 653100, P.R. China. e-mail: hugiufena@163.com Received 19 August 2002; accepted 20 October 2002     

Syntheses of new 1,2-, 1,3-, and 1,4-diazine derivatives. 2. Hydrolysis and alkylation of diazinylphenylacetonitriles

A number of aryldiazinyl acetonitriles were subjected to hydrolysis, methylation, and benzylation reactions. They resulted in the formation of aryldiazinylacetamides, diazinylmethylacetonitriles, and benzyldiazinylacetonitriles, respectively. Published in Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1534–1540, October, 2006.     

Synthesis and In Vitro Characterization of Selective Cannabinoid CB2 Receptor Agonists: Biological Evaluation against Neuroblastoma Cancer Cells

1,8-naphthyridine-3-carboxamide structures were previously identified as a promising scaffold from which to obtain CB2R agonists with anticancer and anti-inflammatory activity. This work describes the synthesis and functional characterization of new 1,8-naphthyridin-2(1H)-one-3-carboxamides with high affinity and selectivity for CB2R. The new compounds were able to pharmacologically modulate the cAMP response without modulating CB2R-dependent β-arrestin2 recruitment. These structures were also evaluated for their anti-cancer activity against SH-SY5Y and SK-N-BE cells. They were able to reduce the cell viability of both neuroblastoma cancer cell lines with micromolar potency (IC₅₀ of FG158a = 11.8 μM and FG160a = 13.2 μM in SH-SY5Y cells) by a CB2R-mediated mechanism. Finally, in SH-SY5Y cells one of the newly synthesized compounds, FG158a, was able to modulate ERK1/2 expression by a CB2R-mediated effect, thus suggesting that this signaling pathway might be involved in its potential anti-cancer effect.     

纳米B2O3/TiO2复合材料的制备及其对痕量银的分离富集性能研究与应用

制备了新型纳米B2O3/TiO2吸附材料,并采用扫描电镜(SEM)及红外光谱(IR)对其进行表征,优化了纳米B2O3/TiO2复合材料对试液中痕量银的吸附和解吸条件,建立了纳米B2O3/TiO2分离富集-原子吸收光谱测定痕量银的新方法。当pH 4.3时,在22℃下振荡20 min,Ag+能被该材料快速吸附,其静态饱和吸附容量为11.72 mg/g,吸附在纳米B2O3/TiO2上的Ag+可用0.1 mol/L HNO3-0.05 mol/L硫脲(1∶4)完全洗脱。该方法的检出限为2.01μg/L,线性范围为0.01～4.00 mg/L,相对标准偏差(RSD)为1.8%,加标回收率为95%～105%。方法应用于实际矿渣样品中痕量银的测定,结果满意。     

Nitroketene dithioacetal chemistry. Part 2: Synthesis of novel 4-(alkylsulfanyl)-2-[1-nitromethylidene]-1,3-dithioles from the dipotassium salt of 2-nitro-1,1-ethylenedithiol

The reaction of the dipotassium salt of 2-nitro-1,1-ethylenedithiol with long chain alkyl halides in acetonitrile medium furnished the novel heterocyclic, 4-(alkylsulfanyl)-2-[1-nitromethylidene]-1,3-dithioles.     

Synthesis and characterization of [2-(2-phenyl-5,6-dihydro-4H-1,3-oxazinyl)] tellurenyl chloride

The synthesis and characterization of the first examples of two tellurium compounds based on 2-phenyl-5,6-dihydro-4H-1,3-oxazine substrate are described. Intramolecular Te?N interaction in [2-(2-phenyl-5,6-dihydro-4H-1,3-oxazinyl)] tellurenyl chloride is established by single X-ray crystallography.     

Ferrocene Compounds. XXVII. Synthesis and Structure of 2-(Ferrocenylmethyl)propane-1,3-diol

The title compound was obtained by reduction of diethyl (ferrocenylmethyl)malonate with lithium aluminium hydride in diethyl ether. The structure of this novel ferrocene derivative was assigned by means of elemental analysis, IR, [¹H]NMR, and [¹³C]NMR spectroscopy. The structure was also confirmed by a single crystal X-ray study. The compound crystallizes in monoclinic P2₁/a space group with unit cell dimensions: a = 9.7360(6), b = 27.040(5), c = 14.767(3) Å, = 103.835(6)°, V = 3774.8(11) ų, Z = 12. The asymmetric unit contains three crystallographically independent molecules. In the ferrocenyl moieties, the Fe–C bond distance values are in the range 2.006(5)—2.051(3) Å and C–C distances in the range 1.366(7)–1.425(4) Å. The cyclopentadienyl rings in each of the molecules are mutually twisted by about 13° from the eclipsed conformation. The hydroxyl groups are involved in the intermolecular O–H...O hydrogen bond formation with O-O distances in the range 2.686(3)–2.801(4) Å forming infinite two-dimensional network in a [0 0 1] plane. The crystal structure is additionally stabilized by C–H-O weak intermolecular hydrogen bonds.     

20 （S） -20-O- Camptothecin β-Aminopropionate： Novel Synthesis and Antitumor Activity in vitro

IntroductionCamptothecin(CPT,1, Scheme 1), a pentacyclicalkaloid isolated from theCamptotheca acuminatebyWallet al. in 1966, shows a broad-spectrum antitumoractivity[1]. However, because of its lowwater solubilityand high toxicity, its clinical applicatio…     

Synthesis of α,β-unsaturated dioxanes, dioxolanes and dioxepanes by trans-acetalisation of dimethylacetals with meso or C2-symmetrical 1,2-, 1,3- and 1,4-diols

Several o-dibenzylic diols were prepared reacting organometallics with o-phthalaldehyde at room temperature in ether. The identity of the meso and C₂-symmetrical (d,l) isomers as well as their ratio were determined by chiral gas chromatography. The meso and C₂ (racemic) stereoisomeric diols were easily separated by flash chromatography on silica gel. A set of 18 α,β-unsaturated acetals were then prepared reacting those, as well as commercially available 1,2, 1,3 and 1,4 diols, with the corresponding methylacetals in acidic medium. A trans-acetalisation procedure adapted to the cases of fragile allylic alcohols or unfavorable 1,6 diols-derived dioxonanes based on a Dean-Stark trapping of methanol was also employed.     

Synthesis and Reactions of Polyhedral Compounds. 27. Development of a Synthetic Route for 2- Spiro-substituted 6-Hydroxy-5,7-dimethyl-1,3-diazaadamantanes

Alternative methods for the synthesis of 2-spiro-substituted 6-hydroxy-5,7-dimethyl-1,3-diazaadamantanes have been developed. These are the reduction of the ketone group to hydroxyl in the corresponding 6-oxo-1,3-diazaadamantanes and the condensation of 9-hydroxy-1,5-dimethyl-3,7-diazabicyclo[3.3.1]nonane (obtained by different routes from 5,7-dimethyl-6-oxo-1,3-diazaadamantane) in reaction with cyclic ketones.     

Synthetic studies on the dienophile unit of methyl isosartortuoate. Part 2: SmI2-mediated 14-membered carbocyclization

The dienophile unit of methyl isosartortuoate has been synthesized. The 14-membered carbocycle was constructed by a SmI₂-mediated intramolecular Reformatsky reaction. The introduction of the oxo group at the γ-position of the α,β-unsaturated ester was achieved by rearrangement of an β,γ-epoxy ester.