新的氨化—还原试剂——二烷基胺硼氢化锂（LAB）

介绍了一种新的氨化-还原试剂——二烷基胺硼氢化锂，讨论了它在卤代苯腈中的应用，其结果为σ—卤代苄腈在与通用的新氨化一还原试剂反应得到相应的氯基苄胺。     

达村斯(Darzens)缩合反应的研究与应用进展

简单介绍了Darzens缩合反应,综述了α-卤代腈、α-卤代酮、α-卤代砜、α-卤代酯、α-卤代酰胺等与醛、酮的Darzens缩合反应以及氮杂Darzens缩合反应,对Darzens缩合反应的应用进行了总结和展望。指出应加强对Darzens缩合反应的系统研究,特别是对手性催化Darzens缩合反应及氮杂Darzens缩合反应的研究。     

由卤代芳硝基物制备卤代芳胺的综述

综述了由卤代芳硝基物还原制备卤代芳胺的三类方法,对三类还原方法的优缺点进行了对比和讨论,重点介绍了第三类制备卤代芳胺的还原方法-催化加氢还原法,最后介绍了催化加氢还原卤代芳香硝基物的新方法及新领域。     

柯诺拉赞-d3的合成

以2-氟苯乙酮(2)为起始原料,经溴代、丙二腈取代、环合、脱氯得到5-(2-氟苯基)-1H-吡咯-3-甲腈(6),然后与1-(3-甲氧基丙氧基)苯磺酰氯(7)发生亲核取代反应得到5-(2-氟苯基)-1-((3-(3-甲氧基丙氧基)苯基)磺酰基)-1H-吡咯-3-甲腈(8),再经催化氢化、还原氨化得到柯诺拉赞-d₃(1),其结构经NMR和MS确证,7步总收率为14.1%,化学纯度为99.5%,同位素丰度为98.3%,可作为稳定同位素内标试剂用于临床药物代谢动力学研究。     

脂肪酮和β-酮酯类化合物与二卤海因的α-卤代反应

各种脂肪酮、β-酮酯和1,3-丙二酸酯类的α-卤代化合物是医药、农药等精细有机合成化学品的重要中间体。它们通常是使用氯气、SOCl2、SO2Cl2、HCl和液溴等卤代试剂对相应的酮和丙二酸酯类化合物进行直接卤代而得。但由于该类试剂的毒性和对设备的腐蚀性,生产和运输上的安全性问题及产生大量酸性废气等原因,它们的使用日益受到限制。因此,近年来,各种酮类化合物的绿色卤代试剂及其绿色卤代方法,     

3,6-二氯-2-氨基吡啶的化学合成方法

正本发明公开了一种卤代氨基吡啶3,6-二氯-2-氨基吡啶的合成方法,它是以2,3,6-三氯吡啶为起始原料,采用氨化试剂一步反应,经过简单后处理得到目标产品3,6-二氯-2-氨基吡啶,收率高、产品品质好。本发明与现有公开技术相比:反应步骤少,原料易得,能耗低、制造成本低、工艺本质安全性高、更易于实现工业化生产。     

沙坦类抗高血压药物关键中间体4 -甲基-2-腈基联苯的合成研究

以对氯甲苯和邻氯苯腈为原料,在锰和含磷的卤代物催化下高效合成4-甲基-2-腈基联苯,催化稳定,工艺简单成熟,适合大规模生产。     

无金属催化合成3-苯基-4-卤代异喹啉类化合物

以邻炔基苄基叠氮和卤盐为原料,利用无金属氟试剂selectfluor作为氧化剂氧化卤盐发生亲电交换反应产生亲电试剂,然后参与叠氮与炔烃的亲电环化反应合成3-苯基-4-氯代异喹啉。实验结果表明:无金属氟试剂selectfluor可以很好的氧化卤盐产生亲电试剂得到产率35%~84%的3-苯基-4-卤代异喹啉类化合物,其结构经~1H NMR,~(13)C NMR和GC-MS表征。该方法反应条件温和、操作简单,并且在产物骨架中引入卤原子,为新官能团的引入提供了途径。     

相转移催化下单硝基氯苯的氨化反应

<正> 芳香族卤代苯的氨化是在芳环上引进氨基的一条重要途径。在染料、药物等的中间体合成中有着极为重要的应用。此类反应属芳香族的亲核取代,而氨在常温下为气体,单硝基卤代苯的氨化反应一般要在高温、高压下才能进行。为了使硝基卤代苯的氨化反应在较温和条件下进行,人们做了不少的研究和探讨。传统的方法是采用铜盐催化,但条件仍较苛刻。Ronde-strest报导邻硝基氯苯与氨在甲酰胺中进行反应。反应温度200～     

五种苯乙醇胺类β受体激动剂的合成研究

以廉价的4-氨基苯乙酮为原料,通过苯环被溴化或氯化,再经腈化、α-氢溴化、有机胺胺化,最后通过硼氢化钾将羰基还原,可以得到溴布特罗、克伦特罗、西布特罗、西马特罗、溴氯布特罗5种苯乙醇胺类β受体激动剂。通过合成路线的合理设计,原料卤代反应后的中间体都可以作为后续反应的物料,原子利用率高,实现了绿色合成化学的目的。对产物结构经行了~1HNMR确认,其HPLC纯度在99%以上,可作为测定β受体激动剂的对照品试剂,满足食品安全的检测需求。     

Victrex® poly(ethersulfone) (PES) and Victrex® poly(etheretherketone) (PEEK)

Properties of two high performance engineering thermoplastics, amorphous polyethersulfone (PES) and semicrystalline polyetheretherketone (PEEK), are discussed. Both resins can be processed by conventional techniques, compounded with high performance fibers, and have high service temperature (up to 300°C). Due to the amorphous character PES can be dissolved and spray coated into metals.     

Photopyroelectric Spectroscopic Studies of ZnO-MnO(2)-Co(3)O(4)-V(2)O(5) Ceramics

Photopyroelectric (PPE) spectroscopy is a nondestructive tool that is used to study the optical properties of the ceramics (ZnO + 0.4MnO(2) + 0.4Co(3)O(4) + xV(2)O(5)), x = 0-1 mol%. Wavelength of incident light, modulated at 10 Hz, was in the range of 300-800 nm. PPE spectrum with reference to the doping level and sintering temperature is discussed. Optical energy band-gap (E(g)) was 2.11 eV for 0.3 mol% V(2)O(5) at a sintering temperature of 1025 °C as determined from the plot (ρhυ)(2)versushυ. With a further increase in V(2)O(5), the value of E(g) was found to be 2.59 eV. Steepness factor 'σ(A)' and 'σ(B)', which characterize the slope of exponential optical absorption, is discussed with reference to the variation of E(g). XRD, SEM and EDAX are also used for characterization of the ceramic. For this ceramic, the maximum relative density and grain size was observed to be 91.8% and 9.5 μm, respectively.     

(Ba_(1-α)Sr_α)_(4.8)(Sm_(0.7)La_(0.3))_(8.8)Ti_(18)O_(54)陶瓷的微波介电性能

采用固相合成法制备了(Ba(1-α)Srα)4.8(Sm0.7La0.3)8.8Ti18O54(α=0.1～0.5)系陶瓷,表征了该陶瓷的相组成和显微结构,测试了微波介电性能.结果表明:α=0.3时,(Ba(1-α)Srα)4.8(Sm0.7La0.3)8.8Ti18O54系陶瓷为单相的新钨青铜结构固溶体.α>0.3时,相继出现了第二相BaLa2Ti4O12和La0.66TiO2.993.随α的增加,(Ba(1-α)Srα)4.8(Sm0.7La0.3)8.8Ti18O54系陶瓷的相对介电常数(εr)先增大后有所波动,品质因数(Qf)先增大后减小,谐振频率温度系数(τf)单调减小.α=0.3时,在1 350℃烧结的陶瓷的微波介电性能最佳:εr=98.77,Qf=5184GHz,τf=10.9×10-6/℃,优于不掺杂的BaO-Sm2O3-TiO2陶瓷的.     

Calcium silicate hydrate (II) (“C-S-H(II)”)

This semicrystalline phase, originally named ‘calcium silicate hydrate(II)’ by Taylor (1950), has been studied with X-rays, electron optics, chemical investigation of silicate anion type, infrared spectra, and thermal methods. It is structurally related to jennite (C₉S₆H₁₁) and probably also to the fibrous CSH of cement pastes, the three phases forming a sequence of decreasing crystallinity. The specimen studied had approximate composition C₂SH_3.2 after standing over saturated CaCλ₂ at about 15°C. CSH(II) contains metasilicate chains and pyrosilicate groups and has a disordered layer structure. Much of the water can be lost reversibly without significant change in lattice parameters.     

Poly(butadiene-acrylic acid(g)acrylonitrile(g)acrylic acid)

Summary In the present work we describe, the synthesis and characterization of a new gel obtained by crosslinking a cooligomer of butadiene-acrylic acid (BuAA), by reaction with acrylonitrile and acrylic acid. The purified product was characterized by FTIR, elemental analyses and scanning electronic microscopy. The thermal properties were studied and swelling indexes were determined in different solvents and at different pH values. The capacity of poly(butadiene-acrylic acid(g)acrylonitrile(g)acrylic acid) [gel A] to separate different organic substances, such as amino acids and colorants, was determined.     

Chemical cross-linking of conducting poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) using poly(ethylene oxide) (PEO)

Hybrid films of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) were prepared with different molecular weights of poly(ethylene oxide) (PEO). The cross-linking reaction between PEO and PEDOT:PSS was performed at high temperature and confirmed by using differential scanning calorimeter (DSC), contact angle measurement, and solid-state ¹H NMR. The effect of chemical reaction on the conductivity and morphology of these hybrid films was studied by using 4-point probe and atomic force microscope (AFM), respectively. As-spun PEO/PEDOT:PSS films have lower electric conductivity due to the addition of nonconductive PEO, and exhibits no molecular weight dependence on conductivity. After chemical cross-linking reaction at high temperature, only PEDOT:PSS films with lowest molecular weight PEO additives show enhanced conductivity with increasing reaction time. AFM result indicates that the heat-treated PEO/PEDOT:PSS hybrid films show grain-like morphology compared to ethylene glycol treated PEDOT:PSS films which shows continuous PEDOT domain. In the present work we demonstrate that the cross-linking reaction can be used to improve the wet stability of PEDOT:PSS nanofiber, showing good water resistance and excellent dimensional stability.     

Photooxidative stability of substituted poly(phenylene vinylene) (PPV) and poly(phenylene acetylene) (PPA)

The addition of side groups to improve the photooxidative stability of polymers used in polymer-based light-emitting diodes (LEDs) is explored. Infrared spectroscopy and computational chemistry techniques are used to study the effects of chemical substitution of the reactive vinylene moiety in poly(phenylene vinylene) (PPV). The bond order of the vinylene group in small oligomers is calculated using semiempirical techniques to assess the improvement in stability toward oxidants such as singlet oxygen. We find that PPV dimers allow relative comparisons across a range of possible substitutions. Experimental results correlate well with these calculations. The addition of electron-withdrawing substituents, such as nitrile groups, to the vinylene moiety is found to be particularly effective in reducing the reactivity of alkoxy-substituted PPV toward singlet oxygen. The photooxidative stability of a poly(phenylene acetylene) (PPA) derivative is also studied. It appears that this family of polymers is more stable toward photooxidation than are its PPV analogs. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 2451–2458, 1998     

Thermal studies of blends of poly(phenylene sulfide) (PPS) with poly(phenylene sulfide sulfone) (PPSS) and with poly(phenylene sulfide ether) (PPSE)

The miscibilities of poly(phenylene) sulfide/poly(phenylene sulfide sulfone) (PPS/PPSS) and poly(phenylene) sulfide/poly(phenylene sulfide ether) (PPS/PPSE) blends were invesigated in terms of shifts of glass transition temperatures T_g of pure PPS, PPSS, a dn PPSE. The crystallization kinetics of PPS/PPSS blends was also studied as a function of molar composition. The PPS/PPSS and PPS/PPSE blends are respectively partially and fully miscible. PPSE shows a plasticizing effect on PPS as does PPS on PPSS, which necessarily improves te processibility in the respective systems. We can control T_g and melting temperature T_m of PPS by varying amounts of PPSE in blends. The melt crystallization temperature T_mc of PPS/PPSE blends was higher than that of the PPSE homopolymer. Therefore, these blends require shorter cycle times in processing than pure PPSE. The overall rate of crystallization for PPS/PPSS blends follows the Avrami equation with an exponent ?2. The maximal rate of crystallization for PPS/PPSS blends occurs at a temperatre higher by 10°C than that for PPS, while the crystallization half time t_1/2 is 4 times shorter. In the cold crystallization range, crystal growth rates increase and Avrami exponents decrease significantly as the temperature increases.