综合创新型实验:乙胺嘧啶合成的设计与教学实践

乙胺嘧啶(商品名:达拉匹林)是一种抗寄生虫药物,改进了合成方法,并设计转化为创新型综合教学实验。从对氯苯乙腈出发,使用丙酸乙酯为酰化试剂,在叔丁醇钾作用下得到烯醇前体。在三甲基氧鎓四氟硼酸盐(Me3O·BF4,Meerwein盐)和碱作用下进行选择性甲基化反应得到烯醇甲醚后,与胍在碱性条件下环化得到最终产物达拉匹林,并通过红外光谱、核磁共振对其结构进行表征。改进后的实验方法具有重现性好、毒性低、操作方便、实验微型化等优点。实验过程中不仅提升了学生的实验技能和科研思维,更提高了学生的创新能力和绿色环保意识。     

牛血清白蛋白与十二烷基硫酸钠作用的机理

利用电动势法得到了牛血清白蛋白(BSA)与十二烷基硫酸钠(SDS)相互作用的结合等温线. 通过四阶导数紫外光谱法和荧光光谱法研究了相互作用过程中芳香族氨基酸残基微环境极性的变化. 通过研究发现, 随着SDS浓度的逐渐增大, SDS在BSA上的平均结合数(v)逐渐增大, 色氨酸(Trp)残基所处微环境的极性在减弱后保持基本不变, 酪氨酸残基所处微环境的极性在明显增强后稍有减弱, 苯丙氨酸残基所处微环境的极性略有增强. 结果表明, 当v由0增大到14时, SDS主要结合在BSA的Trp-213附近并逐渐形成聚集体, 从而诱导BSA由结构域ⅡA 开始逐渐展开. 此后, SDS呈正协同作用的特点与BSA 结合, v急剧增大. 当v约为302 时, SDS在BSA上的结合基本达到饱和, BSA的构象趋于稳定.     

SYNTHESIS OF A NOVEL "MESOGEN-JACKETED LIQUID CRYSTAL POLYMER" BASED ON VINYLTEREPHTHALIC ACID

Poly{2, 5- bis [ (p- methoxyphenyl ) oxycarbonyl] styrene } was successfully syn-thesized. This new polymer has a structure characteristic of mesogen-jacketed liquidcyrstalline polymers (MJLCPs) and does form a liquid crystal phase above its glass tran-sition. It thus became the starting member of a new series of MJLCPs. The synthesis ofthe polymer as well as the liquid crystalline properties of the polymer and its monomerwas discussed. A brief comparison of the new monomer and polymer with some previouslyreported counterparts was also included.     

STUDIES ON THE CRYSTAL STRUCTURE OF Al-(D-TRYPTOPHAN) INSULIN

We have determined the crystal structure of Al-(D-Trp) insulin and discovered that it belongs to the trigonal system with space group R3. The parameters of the unit cell are a=b=78.6, c=50.0. A set of data for half a sphere reciprocal space to a spacing of 2.2 were collected. The model was adjusted and refined by using a step-by-step approach and a stereochemically-restrained least squares program, assisted by manual revision based on the difference Fourier maps, to a final R-factor of 0.218. The main and side chains of both Al-D-Trp residues in the asymmetric unit are well ordered. The packing of Al-(D-Trp) insulin in the unit cell, the conformational differences with other insulin structures and its structure and function relationship bave also been discussed.     

离子液体存在下脂肪醛的环化三聚反应

Aliphatic aldehydes such as ethanal,propanal,n-butanal,isobutyraldehyde,n-valeraldehyde,isovaleraldehyde,n-hexanal and n-octanal were converted into the corresponding 2,4,6-trialkyl-1,3,5-trioxanes through cyclotrimer-ization in the presence of the ferric chloride based ionic liquids at room temperature without solvent in high selec-tivity.The effects of different ionic liquids,acidity of ionic liquids and temperature on cyclotrimerization were alsostudied.The results showed that the ferric chloride based ionic liquids(apparent molar fraction of FeCl_3(x(FeCl_3)=0.62))were a kind of efficient catalysts for the cyclotrimerization of aliphatic aldehyde which could be separatedconveniently from the reaction mixture and recycled without loss of catalytic activity.The conversion of isobu-tyraldehyde and the selectivity to 2,4,6-triisopropyl-1,3,5-trioxane were 91.1% and 99.8% respectively under opti-mum reaction condition(isobutyraldehyde 25.0 g,[Et_3NH]Cl/FeCl_3(x(FeCl_3)=0.62)1.0 g,25 ℃for 1 h).     

CATIONIC CONDUCTIVITY FOR THE CROSSLINKED P [OLIGO (OXYETHYLENE) METHACRYLATE-COoMETHACRYLOYL ALKYLSULFONIC ACID LITHIUM]

Crosslinked copolymers with single Li~+-ionic conductivity were prepared from oligo (oxyethylene) methacrylate (MEO_n), methacryloyl alkylsulfonic acid lithium (SAMLi), and oligo (oxyethylene) dimethacrylate (DMEO_n). Li~+-ionic conductivity of the copolymer is improved by crosslinking and presented as a function of polymerization degree (n) in MEO_n, comonomeric salt concentration (O/Li), and crosslinking degree. The crosslinked copolymer P (0.7 MEO_(14)-0.3DMEO_(14)-SHMLi) without other small molecular additives exhibits an optimum Li~+-ionic conductivity of 1.2×10~(-6) S/cm at 25℃. Dc polarization test in the cell composed of Li/copolymer/Li shows a constant dc ionic conductivity which closes gradually to the ac one with decreasing dc polarization potential.     

新型含二茂铁有机配合物的合成及其电化学性质

以二茂铁为起始原料,经氯汞化反应、溴代反应、Suzuki偶联反应、水解反应和取代反应等5步反应合成了一种新型的含二茂铁结构单元的有机配合物(7),其结构经1H NMR、13C NMR、IR和HR-MS(ESI-TOF)表征。电化学研究结果表明:化合物6的E1/2小于化合物7,具有较高的氧化还原活性。     

手性锌卟啉对咪唑类客体分子识别的构象研究

Chiral recognition is an attractive subject in the area of host-guest chemistry. Conformation study is performed to understand chiral recognition of zinc(Ⅱ) porphyrin with imidazole derivatives on a molecular level. The molecular recognition of three novel chiral zinc porphyrin(1-3) with four types of imidazole derivatives was studied. The conformation searching of this host-guest system was studied by using simulated annealing method on the basis of Tripos force field. The different minimal energy conformation of imidazole combind with porphyrin was studied. The quantum chemistry calculation was performed to calculate the single-point energies of the host-guest system. The minimal energy conformation of ZnT(o-BocAla)APP (3)-Im showed that Im attaching from the single-side chain of the host had the reasonable configuration than that from the three-side chain. The former also had the lower energy than the latter. And the quantum chemistry calculation results of orbital energy, ΔE_L-H, and atomic net charge revealed the same way. The results illumate that combination oriention of the host-guest system is the single chain of the hosts.     

α-(2-苯并噻唑氧基)烃基膦酸酯的合成性质和生物活性

为探索α-芳(杂 环)磷酸衍生物的生物活性,寻求含磷农药的新母体,合成了十六个未见文献报道的α-(苯并噻唑-2-氧代)烃基膦酸衍生物,所有化合物的结构均IR,HNMR, 元素分析等确证,并对生物活性进行了初步的研究.     

Theoretical Study of the Low-Lying Excited States of Butoxy Radicals and Non-Radiative Decay Routes

The potential energy surfaces for the butoxy radical dissociation into R·＋O on the six low-lying electronic states have been determined with the combined CASSCF and MR-CI methods. The isomerization reactions between the different conformers of 1- and 2-butoxy radicals at the X and B states have been also investigated with the MP2, B3LYP, and CASSCF methods. The non-radiative decay mechanisms of butoxy radicals at the B state have been characterized with the computed potential energy surfaces and intersections. Supported by recent LIF experimental results, it was predicted that the t-butoxy radical would predissociate via the B/C intersection. As to 1- and 2-butoxy radicals, the relative energies of the transition states for the isomerization reactions between conformers at the B state are much lower than those of the B/C intersections, resulting in the predominance of the isomerization in the decay of the B state for 1- and 2-butoxy radicals.