2-氯-3-乙磺酰基吡啶合成方法的改进

2-氯-3-乙磺酰基吡啶是合成砜嘧磺隆的中间体,目前合成该中间体的路线较多,但收率均不高。以巯基乙腈为起始原料,经4步反应合成了中间体2-氯-3-乙磺酰基吡啶。该路线原料易得,操作方便,易于工业化生产。     

玉嘧磺隆新合成方法研究

玉嘧磺隆是杜邦公司研发成功的磺酰脲类除草剂。以3-乙基磺酸-2-吡啶磺酰胺为原料,在二氯亚砜的作用下生成亚硫酰吡啶磺酰胺,然后再和三光气反应得到磺酰胺异氰酸酯,不需要提纯直接和2-胺基-4,6-二甲氧基嘧啶加成即得到玉嘧磺隆。此方法提高原子经济性。提供了一条新的合成主嘧磺隆的方法。     

一种微波法合成2-卤代-3-取代烃基磺酰基吡啶及其中间体的方法

本发明公开了一种微波法合成2-卤代-3-取代烃基磺酰基吡啶及其中间体的方法,反应器中加入取代氨基丙烯醛、催化剂和取代基氰乙基砜,在微波辐射下反应,跟踪反应至取代氨基丙烯醛或取代基氰乙基砜完全反应,制得中间体;然后向反应液中加入卤化氢继续反应,跟踪检测至反应完全;反应液中加入碱液调节p H值至7-8,静置分层得到水层和有机层,水层用有机溶剂萃取,然后合并有机层,再经过精制,制得2-卤代-3-取代烃基磺酰基吡啶。本发明所述的2-卤代-3-取代烃基磺酰基吡啶的合成方法具有绿色环保、反应时间且操作简单、产品收率高和产物具有较好的杀菌活性的优点。     

啶嘧磺隆的合成研究

啶嘧磺隆是一种草坪专用的含氟磺酰脲类除草剂.啶嘧磺隆是以2-氯-3-三氟甲基吡啶为原料,进一步反应后与2-氨基-4,6-二甲氧基嘧啶合成制得.     

砜嘧磺隆分子印迹单分散聚合物微球的制备及表征

[方法]以砜嘧磺隆为模板分子,采用沉淀聚合法制备分子印迹聚合物。[结果]紫外光谱分析砜嘧磺隆与MAA最佳比例为1∶4。红外光谱研究表明MIPs与NIPs具有相同的化学结构。粒径对比分析表明砜嘧磺隆与MAA以特定的比例形成了单分散聚合物微球,MIPs粒径为0.1-1.2μm。通过静态平衡结合实验测定MIPs对砜嘧磺隆的最大表观吸附量为5085 mg/kg。[结论]研究合成的MIPs比NIPs具有更强的吸附性能,且对磺酰脲类具有选择吸附性。     

2-溴-3-乙磺酰基吡啶的合成

2-溴-3-乙磺酰基吡啶是磺酰脲类除草剂玉嘧磺隆重要中间体.以乙磺酰基乙腈和1,1,3,3-四甲氧基丙烷为起始原料,经取代、环合反应合成得到目标产物.含量≥95.0%,收率75.5%(以乙磺酰基乙腈计).     

新型除草剂玉嘧磺隆的合成研究

玉嘧磺隆是磺酰脲类除草剂。以乙磺酰基乙腈和1,1,3,3-四甲氧基丙烷为起始原料,经消除加成、取代、环合、硫代、磺酰胺化、缩合六步反应合成得到玉嘧磺隆,总收率(以乙磺酰基乙腈计)38.8%,含量大于98.5%。产物及中间体结构经1HNMR、MS表征,结构正确。     

2009-2010年专利届满的国外除草剂品种概况

乙氧嘧磺隆（ethoxysulfuron）乙氧嘧磺隆又名：Sunrice、太阳星。化学名称：1-（4,6-二甲氧基嘧啶-2-基）-3-（2-乙氧苯氧磺酰基）脲。该品种由德国拜耳作物科学公司开发.获中国专利授权（CN1038643）,该专利将于2009年5月15日 到期；     

2-氨基-4,6-二甲氧基嘧啶的合成

正磺酰脲类除草剂主要是在上世纪80年代发展起来的,是一类广谱高效的水稻、玉米、大豆田地除草剂,具有活性高、用量少以及毒性低等特点,在世界上被公认为高效、环保的绿色型农药。在磺酰脲类除草剂的生产中,2-氨基-4,6-二甲氧基嘧啶是其合成的重要中间体,以其为原料制备的磺酰脲类除草剂品种有很多,如烟嘧磺隆、苄嘧磺隆、吡嘧磺隆、嘧啶磺隆、砜嘧磺隆、乙氧嘧磺隆、酰嘧磺隆、啶嘧磺隆、环丙嘧磺隆、玉嘧磺隆、四     

新型噁嗪酮类除草剂的合成和除草活性

尽管磺酰脲类除草剂如苄嘧磺隆、吡啶磺隆和咪唑磺隆已经在日本广泛用于防除稻田杂革，但其对稗草类除草活性剂略显不足。为了克服这个缺点．科研人员努力开发新颖高效的除草剂。公布的多种候选结构中包括：2-（4，6-二甲氧基嘧啶-2-基）羟苯甲酸，N，N-二烷基氨基甲酰三唑，2-（2-苯环氧乙烷-乙基甲级）茚满-1，3-二酮和1-苯基-4-二烷基氨基甲酰四唑啉酮。     

反应与精馏耦合水解醋酸甲酯(英文)

A process composed of a fixed-bed and a distillation column with a side withdraw, mainly methanol, is developed to hydrolyze methyl acetate (MA) as a typical byproduct in polyvinyl alcohol (PVA) and pure terephthalic acid (PTA) factory. The process is simulated by employing the equilibrium stage model RadFrac and plug flow model Rplug in Aspen Plus. Experiments are also carried out in a lab-scale to evaluate the process. The results show that at the molar ratio of water to methyl acetate about 4.0-5.0 in the feed stream and the volume ratio of distillate to feed MA above a critical value, the side product contains more than 80% (by mass) (MeOH) and less than 2% (by mass) MA, while the bottom contains more than 46% (by mass) acetic acid (HAc) and less than 0.5% (by mass) methanol with almost complete conversion of MA. Compared with the old catalytic distillation process we proposed before, this process can cut down 47.6% energy consumption and a distillation column.     

Design of fluidized bed photoreactors: Optical properties of photocatalytic composites of titania CVD-coated onto quartz sand

Volumetric optical properties (spectral absorption, scattering and extinction coefficients) of differently expanded narrow-path fluidized beds (FB) of a photocatalyst obtained by plasma-CVD deposition of titania onto quartz sand, relevant for photoreactor design purposes, are determined by using an unidirectional and unidimensional (1DD) model for the solution of the radiative transfer equation (RTE). Two simplified approaches are used: a Kubelka-Munk (KM) type of solution, by which the RTE is transformed into a pair of ordinary differential equations, and a discrete ordinate method (DOM) by which the complete RTE is transformed into an algebraic system that can be solved computationally. The second approach was validated by introducing the obtained optical parameters into a more elaborated bi-directional and two-dimensional (2DD) DOM model. Despite its simplicity, the KM method was able to yield fair order-of-magnitude estimates of the spectral optical properties of these FB.     

从假性紫罗兰酮合成β-紫罗兰酮中主要副产物(I)的分离鉴定

假性紫罗兰酮在浓硫酸及 - 2 0°C低温条件下反应 ,主要生成 β-紫罗兰酮 ,少量的 α-及 γ-紫罗兰酮 ,同时生成副产物 ( I)及 ( II)。用 IR、1H NMR及 MS光谱分析方法 ,对副产物 ( I)进行了结构鉴定 ,结构为 3,4,4a,5 ,8,8a-六氢 - 2 ,5 ,5 ,8a-四甲基 - 2 H - 1 -苯并吡喃     

Synergistic Extraction of Am(III) and Eu(III) by Tris(2‐pyridylmethyl)Amine with Various Anions in 1,2‐Dichloroethane

The extraction equilibria of Am(III) and Eu(III) by using a tripodal ligand, tris(2‐pyridylmethyl)amine (tpa), with various lipophilic anions have been investigated. The extractability of both Am(III) and Eu(III) was increased by the combination of tpa and counteranions due to a synergistic effect. The separation factors between Am(III) and Eu(III) were also increased from 7.6 to 49 by the combination of counteranions and organic solvents. The extraction equilibria of Am(III) and Eu(III) with tpa in 1,2‐dichloroethane were determined by slope analysis. It was found that three anions and one molecule of the ligand coordinated to Am(III) and Eu(III) was extracted regardless of the anions.     

scyllo-inositol pentakisphosphate as an analogue of myo-inositol 1,3,4,5,6-pentakisphosphate: chemical synthesis, physicochemistry and biological applications

myo-Inositol 1,3,4,5,6-pentakisphosphate (Ins(1,3,4,5,6)P(5)), an inositol polyphosphate of emerging significance in cellular signalling, and its C-2 epimer scyllo-inositol pentakisphosphate (scyllo-InsP(5)) were synthesised from the same myo-inositol-based precursor. Potentiometric and NMR titrations show that both pentakisphosphates undergo a conformational ring-flip at higher pH, beginning at pH 8 for scyllo-InsP(5) and pH 9 for Ins(1,3,4,5,6)P(5). Over the physiological pH range, however, the conformation of the inositol rings and the microprotonation patterns of the phosphate groups in Ins(1,3,4,5,6)P(5) and scyllo-InsP(5) are similar. Thus, scyllo-InsP(5) should be a useful tool for identifying biologically relevant actions of Ins(1,3,4,5,6)P(5), mediated by specific binding sites, and distinguishing them from nonspecific electrostatic effects. We also demonstrate that, although scyllo-InsP(5) and Ins(1,3,4,5,6)P(5) are both hydrolysed by multiple inositol polyphosphate phosphatase (MINPP), scyllo-InsP(5) is not dephosphorylated by PTEN or phosphorylated by Ins(1,3,4,5,6)P(5) 2-kinases. This finding both reinforces the value of scyllo-InsP(5) as a biological control and shows that the axial 2-OH group of Ins(1,3,4,5,6)P(5) plays a part in substrate recognition by PTEN and the Ins(1,3,4,5,6)P(5) 2-kinases.     

Visible-light-induced photoelectrochemical behaviors of Fe-modified TiO2 nanotube arrays

Fe-modified TiO(2) nanotube arrays (TiO(2) NTs) were prepared by annealing amorphous TiO(2) NTs whose surface was covered with Fe(3+) by a dip-coating procedure, and characterized by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and UV-visible reflectance spectroscopy. The photoelectrochemical properties were evaluated by the photocurrent response and photoelectrocatalytic (PEC) degradation of methylene orange (MO) and 4-chlorophenol in water under visible-light irradiation (λ > 420 nm). The results showed that a Fe-modified TiO(2) NTs electrode exhibited a larger photocurrent response and higher PEC activity for the degradation of organic pollutants than a pure TiO(2) NTs electrode. At a bias potential of 0.4 V, the photocurrent response of a 0.5 M Fe-modified TiO(2) NTs electrode exceeded that of a pure TiO(2) NTs electrode by a factor of about 10, and the PEC degradation rates of MO and 4-chlorophenol on a 0.5 M Fe-modified TiO(2) NTs electrode exceeded those on a pure TiO(2) NTs electrode by a factor of about 2.5. The larger photocurrent response and higher PEC activity of Fe-modified TiO(2) NTs could be attributed to the enhancement of separation of charge-carriers at the external electric field and the extension of the light response range of TiO(2) to the visible-light region with the narrowing of the band gap.     

Oxidized Lipoprotein(a) Increases Endothelial Cell Monolayer Permeability via ROS Generation

Oxidized lipoprotein(a) (oxLp(a)) is a more potent marker of atherogenesis than native Lp(a). However, the molecular mechanisms of oxLp(a) activity are not clear. Reactive oxygen species (ROS) have recently been suggested as acting as intracellular second messengers. In this study, the effects of oxLp(a) on endothelial cell monolayer permeability and the role of reactive oxygen species (ROS) generation in these effects were investigated. Our results showed that oxLp(a) inhibited desmoglein-1 (DSG1) and desmocollin-2 (DSC2) expression at both mRNA and protein levels in a dose- and time-dependent manner, and increased the generation of cellular ROS. Down-regulation of DSG1 and DSC2 was strengthened by pretreatment with H₂O₂ and attenuated by superoxide dismutase (SOD) treatment. Furthermore, oxLp(a) increased endothelial cell monolayer permeability, and this effect was enhanced by H₂O₂ and blunted by SOD. Taken together, these results demonstrate that oxLp(a) increases endothelial cell monolayer permeability, which is mediated at least in part via ROS generation.     

Identification of Novel C20 and C22 Trienoic Acids from Arctiid and Geometrid Female Moths that Produce Polyenyl Type II Sex Pheromone Components

Gas chromatography-mass spectrometry (GC-MS) and GC-electroantennographic detection (EAD) analyses of the sex pheromone extract from a wasp moth, Syntomoides imaon (Lepidoptera: Arctiidae: Syntominae), showed that virgin females produced (Z,Z,Z)-3,6,9-henicosatriene and (Z,Z,Z)-1,3,6,9-henicosatetraene with a trace amount of their C(20) analogs. Identification of the chemical structures was facilitated by comparison with authentic standards and the double-bond positions were confirmed by dimethyl disulfide derivatization of monoenes produced by a diimide reduction. In a field test in the Yonaguni-jima Islands, males of the diurnal species were captured in traps baited with a 1:2 mixture of the above-described synthetic C(21) polyenes. Lipids were extracted from the abdominal integument and its associated oenocytes and peripheral fat bodies. Following derivatization, fatty acid methyl esters (FAMEs) were fractionated by HPLC equipped with an ODS column, and methyl (Z,Z,Z)-11,14,17-icosatrienoate and (Z,Z,Z)-13,16,19-docosatrienoate were identified by GC-MS. These novel C(20) and C(22) acid moieties are longer-chain analogs of linolenic acid, (Z,Z,Z)-9,12,15-octadecatrienoic acid. They are presumed to be biosynthetic precursors of the S. imaon pheromone because the C(21) trienyl component might be formed by decarboxylation of the C(22) acid. On the other hand, the C(20) acid, but not the C(22) acid, was found in FAMEs of Ascotis selenaria cretacea (Lepidoptera: Geometridae), which secretes C(19) pheromone components, (Z,Z,Z)-3,6,9-nonadecatriene and the monoepoxy derivative, indicating that different systems of the chain elongation might play an important role in developing species-specific communication systems mediated with polyunsaturated hydrocarbons and/or epoxy derivatives, components of Type II lepidopteran sex pheromones.     

Adsorption characteristics of Ru(II) dye on carbon nanotubes for organic solar cell

We present a study on the adsorption properties of ruthenium(II) dye (Ru(II) dye) on multi-walled carbon nanotubes (MWNTs). To fabricate dye sensitized solar cells (DSCs) using dye coated MWNTs, we have developed a method to form covalently linked adducts of MWNTs and Ru(II) dye. MWNTs were functionalized by sonication in hydrogen peroxide solution. Ru(II) dye can be attached to the functionalized MWNTs by a synthetic route using Thionyl chloride (SOCl₂) followed by ethylenediamine. The adsorption characteristics were affected by parameters such as chemical oxidation of MWNTs, sonication process, processing temperature and time. The amount of adsorbed Ru(II) dye was effectively affected by treatment temperature of SOCl₂ than any other parameters.