α,ω—双（2—苯并咪唑）二硫化合物的简便合成

咪唑具有特异的质子授-受性能、共轭酸-碱性能及识别络合性能,享有“生命配体”之美誉。在自然界中,咪唑作为许多酶的活性中心功能基,参与了许多重要的生物化学反应,对生命活动起着十分重要的作用[1,2]。许多药物、农药、酶抑制剂及精细化学品等也含有咪唑结构组分[3-5]。选用咪唑、双咪唑成功构筑了多种人工受体、人工酶及仿生功能体系[6-9]。探索、拓展咪唑、双咪唑化合物的合成反应及应用是很有意义的。近年,我们报道了含脂肪烃、芳香烃、醚键为桥基的几类双咪唑或双苯并咪唑的合成[10-13],以及手性含硫大环配体的合成[14]。本文报道一类…     

[Cu(HIm)_2(PPh_3)_2](BF_4)的合成与晶体结构

铜?配合物以结构多样化、生物和医药活性和独特的光谱性能而成为活跃的研究领域,其合成、结构以及性能的研究已受到日益广泛的重视,它们与普通配体的分子设计和结构测定涉及生物无机化学,无机合成和金属基药物设计等内容犤１,２犦。咪唑衍生物是常见的生物配体,对生物功能起重要的作用,咪唑氮原子与金属离子配位成键,形成各种金属生物分子的活性中心,通过了解金属与咪唑氮原子配位的结构特点,建立生物活性结构模型配合物,可以达到研究金属酶活性中心结构与物性关系的目的犤３,４犦。生物体中大部分铜与两种以上配体形成混配配合…     

咪唑及其衍生物的合成研究进展

咪唑及其衍生物作为药物中间体,在生物学、医学、有机化学中占据重要位置.目前咪唑的合成方法主要包括Radziszewski法、Phillips法、溴乙醛法.咪唑衍生物的合成方法主要包括金属催化剂合成法、酸性催化剂合成法、离子液体催化剂合成法等.本文对咪唑及其衍生物的合成方法进行了总结与归纳,并阐述了各种方法的优缺点.     

在含水介质中钯高效催化咪唑并[1,2-a]吡啶类化合物与芳基氯代物的碳氢芳基化反应（英文）

3-芳基咪唑并[1,2-a]吡啶骨架广泛存在于药物结构中,在药物学方面具有重要的地位及在材料化学、有机化学等方面也具有潜在的应用价值.在含水介质中,利用醋酸钯催化咪唑并[1,2-a]吡啶及其衍生物与芳基/杂芳基氯代物的碳氢芳基化反应,简便、高效地合成系列3-芳基咪唑并[1,2-a]吡啶类化合物,并以较好至优秀的收率获得芳基化产品.该方法采用廉价易得的芳基/杂芳基氯代物和咪唑并[1,2-a]吡啶类化合物为偶联反应的底物,且底物的范围能够拓展至缺电子、富电子的芳基氯代物和杂芳基氯代物及多种基团取代的咪唑并[1,2-a]吡啶类化合物.     

邻甲基苯磺酸铜催化"一锅法"合成3,4-二氢嘧啶-2(1H)-酮

二氢嘧啶酮(DHPMs)及其衍生物具有广泛的生物活性,如抗病毒、抗肿瘤、抗癌、抗高血压及消炎等作用[1].此外,DHPMs及其衍生物作为钙通道阻滞剂、α1a-对抗剂和神经肽Y的对抗剂,显示出良好的药理活性[2].更重要的是,最近几种含二氢嘧啶酮-5-羧酸盐的海洋生物碱被成功分离出来,并表现出重要的生物学性质[3],某些可以阻止HIVgp-120-CD4键的形成,是一种潜在的HIV抑制剂[4].因此,对DHPMs及其衍生物的研究成为生物活性有机杂环化合物的研究热点之一.     

卟啉衍生物及其高分子材料

卟啉是一类由4个吡咯环通过次甲基相连而形成的共轭大环化合物.卟啉及其衍生物广泛存在于生物体内,参与催化、氧的输运和能量转移等重要生理过程.因其独特的生理功能和物理化学特性,卟啉衍生物及其高分子材料的制备和合成引起了广泛关注.本文介绍了卟啉及其衍生物在生命系统中的功能及其合成方法,回顾了含卟啉的高分子材料和超分子组装体的设计和制备方法,总结了近年来基于卟啉的高分子和超分子功能材料的研究动态.     

碘促进3-(咪唑并[2,1-b][1,3,4]噻二唑-6-基)香豆素衍生物的有效合成

香豆素和咪唑并噻唑是两类具有广泛生物活性和药理作用的杂环化合物,合成含咪唑并噻唑基的香豆素衍生物在药物化学上具有重要意义。本研究发展了一种有效地通过3-乙酰基香豆素和2-氨基-1,3,4-噻二唑,在I_2促进下一锅环化反应合成3-(咪唑并[2,1-b][1,3,4]噻二唑-6-基)香豆素衍生物的方法。目标化合物通过核磁共振、红外光谱、质谱及元素分析进行了结构表征。     

1-异丁基-1H-咪唑并[4,5-c]喹啉衍生物的合成与表征

一些1H-咪唑并[4,5-c]喹啉的衍生物具有免疫调节功能,能诱导干扰素和其他细胞因子的产生,表现为重要的抗病毒和抗增殖活性。本文以1-异丁基-4-氯-1H-咪唑并[4,5-c]喹啉为起始原料,与乙二醇反应,再与苄氧羰基缬氨酸经酰化、脱苄基合成了含1-异丁基-1H-咪唑并[4,5-c]喹啉的缬氨酸盐酸盐。目标化合物及中间体经IR、NMR、MS和元素分析予以确证。     

新型氨基酸尾式卟啉及莫锌配合物的合成与表征

金属卟啉配合物作为主体分子对氨基酸酯及其衍生物的分子识别研究是当今卟啉仿生化学的重要课题[1～6].这一领域的研究成果在生物传感器的研制,癌症的诊断和治疗,模拟含卟啉生物大分子的功能以及在生物大分子构象和类型的识别研究中具有潜在的应用价值[7].     

以亚甲基链桥联的手性联萘酚香豆素衍生物的合成与性质

香豆素类衍生物作为一类重要的香料和有机荧光发色体,以及作为一类具有抗病毒、抗肿瘤等生物活性的化合物,一直被人们所重视.香豆素及其衍生物在溶液中的光二聚反应已经被人们广泛研究[1],已经知道,香豆素类衍生物在波长大于300 nm的光激发下,能发生光环合反应,生成[2+2]的二聚体,这种光二聚体在波长小于300 nm的光激发下又能裂解.     

新型含硫三唑类化合物的合成及生物活性研究

利用1,3-二芳基-2-[(¹H NMR-1,2,4-三唑-1-基)-甲基]-2-丙烯-1-酮与取代苯硫酚进行1,4-亲核加成反应,合成了一类新型含硫三唑类化合物,其结构经元素分析、核磁共振谱和红外光谱确证,并对其进行了生物活性的测试,发现它们具有中等程度的抑菌活性和较好的杀虫活性.     

毛细管气相色谱法测定水果、蔬菜中17种有机氯农药的残留量

采用毛细管气相色谱法测定水果、蔬菜中17种有机氯农药的残留量。用丙酮-正己烷混合液(1：1)提取样品中的有机氯农药，将提取液浓缩后，经过弗罗里硅土层析柱净化，用HP-5毛细管柱分离，再以电子捕获检测器测定，外标法定量。方法的加标回收率为80．7％-113．1％，测定结果的相对标准偏差为9％-17％，检出限为0．5—8．0ng／g。     

Bis(3‐endo‐camphoryl)phosphinic Acid,a Non‐Racemic Helical Supramolecular Host with Aquapores

Bis(3‐endo‐camphoryl)phosphinic acid ( 1 ) was prepared by the reaction of the lithium enolate of D‐(+)‐camphor and phosphorous trichloride followed by an oxidative work up. Compound 1 crystallizes from wet toluene as monohydrate 1 ·H₂O, which was investigated by X‐ray crystallography. Molecules of 1 are associated by strong hydrogen bonds giving rise to the formation of a supramolecular helix. The interior channel of the helix is filled by a one‐dimensional (1D) string of water molecules that are also associated by hydrogen bonding. The 1D string adopts a twisted zigzag conformation. Although the hydrogen bond networks are not cross‐linked both the screw of the helix and the twist of the 1D string of water molecules are left‐handed (M) and controlled by the chiral camphoryl residues situated on the exterior of the helix. The overall supramolecular structure is strongly reminiscent of aquaporin‐1, a significant membrane‐channel protein responsible for the transport of water into the cells.     

Excess Thermodynamic Properties of Binary Liquid Mixtures Containing N,N -Dimethylacetamide with Some Alkan-1-Ols (C 1 -C 6 ) At 298.15 K

Excess molar enthalpies, $ H_m^E $ of N , N -dimethylacetamide + methanol, + ethanol, + propan-1-ol, + butan-1-ol, + pentan-1-ol, and + hexane-1-ol have been determined at 298.15 K and atmospheric pressure using a Parr 1455 solution calorimeter. While the excess molar enthalpies are negative for methanol and ethanol mixtures, those for propan-1-ol, butan-1-o1, pentane-1-ol, and hexan-1-ol mixtures are positive over the entire range of composition of N , N -dimethylacetamide. The $ H_m^E $ at around x , 0.5 follow the order: methanol<ethanol<propan-1-ol<butan-1-ol<pentan-1-ol<hexan-1-ol. The results are explained in terms of the self-association exhibited by the alkan-1-ols and the formation of aggregates between unlike molecules through OHO hydrogen bonding. The experimental results for mixtures are well represented by the Redlich - Kister equation.     

1-苄基-5-烷氧基海因的合成

以苄胺和氯乙酸为原料合成了N-苄基甘氨酸盐酸盐,然后与氰酸钾缩合环化合成了1-苄基海因,再经溴化、烷氧基化反应合成了3种海因衍生物,其中2种未见文献报道.产物经元素分析、IP和1H NMR确证.     

火焰原子吸收光谱法测定重晶石中锌铜铁

提出了火焰原子吸收光谱法测定重晶石中锌、铜和铁的方法 ,相对标准偏差为 1 .7%～7.3% ,加标回收率在 95.2 %～ 1 0 3.2 %之间。特征浓度锌为 0 .0 1 0 μg·ml-1/1 % ,铜为 0 .0 35μg·ml-1/1 % ,铁为 0 .0 67μg· ml-1/1 %。方法简便、准确、可靠。     

The mechanism of carbon dioxide catalysis in the hydrogen peroxide N-oxidation of amines

The reactivity of the peroxymonocarbonate ion, HCO4- (an active oxidant derived from the equilibrium reaction of hydrogen peroxide and bicarbonate), has been investigated in the oxidation of aliphatic amines. Tertiary aliphatic amines are oxidized to the corresponding N-oxides in high yields, while secondary amines give corresponding nitrones. A closely related mechanism for the H2O2 oxidation of tertiary amines catalyzed by CO2 (under 1 atm) and H2O2 at 25 degrees C is proposed. The rate laws for the oxidation of N-methylmorpholine (1) to N-methylmorpholine N-oxide and N,N-dimethylbenzylamine (2) to N,N-dimethylbenzylamine N-oxide have been obtained. The second-order rate constants for the oxidation by HCO4- are k1 .016 M(-1) s(-1) for 1 in water and k1=0.042 M(-1) s(-1) for 2 in water/acetone (5:1). The second-order rate constants for tertiary amine oxidations by HCO4- are over 400-fold greater than those for H2O2 alone. Activation parameters for oxidation of 1 by HCO4- in water are reported (DeltaH=36+/-2 kJ mol(-1) and DeltaS=-154+/-7 J mol(-1) K(-1)). The BAP (NH4HCO3-activated peroxide) or CO2/H2O2 oxidation reagents are simple and economical methods for the preparation of tertiary amine N-oxides. The reactions proceed to completion, do not require extraction, and afford the pure N-oxides in excellent yields in aqueous media.     

Counterion effect on the spin-transition properties of the cation [Fe(btzx)3]2+ (btzx=m-Xylylenebis(tetrazole))

The influence of the counteranion on the structure and the spin-transition properties of original 1D bis(tetrazole) Fe(II) systems, namely [Fe(btzx)(3)]X(2) (X=PF(6) (-) (1), CF(3)SO(3) (-) (2) and ClO(4) (-) (3); btzx=m-xylylenebis(tetrazole)) is studied. The X-ray crystal structures of compounds 1 and 2 are described in detail. These structures present a solvent molecule encapsulated within pockets formed by btzx ligands along the 1D coordination chains. Compound 2 is shown to be the first structurally characterised alternating HS-LS 1D spin-transition system (HS=high spin, LS=low spin). The magnetic susceptibility measurements of all three compounds are compared. The degree of completion and the transition temperature are both drastically influenced by the counterion used, while surprisingly, the cooperative nature of the transition is not affected by the choice of counterion. Compounds 1 and 2 are further studied by M?ssbauer spectroscopy and their distinct LIESST properties are compared.     

Determination of indolalkylamines after selective derivatisation (author's transl)]

The 1N-TMS-omegan-TFA-derivatives of indolalkylamines are suitable for estimation by combined gas chromatography and mass spectrometry for two reasons, viz. (1) Under electron impact charge stabilisation at the indole nucleus is favoured, so structure-specific ions form the base peak. For unsubstituted indoles m/e values of 202 are found and for hydroxyl-substituted indoles m/e values of 290. (2) The calibration curves of the derivatives are linear, even in the femtomole range. The 1N-TMS-omegan-derivatives can easily be obtained by trimethylsilylation with N-methyl-N-trimethylsilyltrifluoroacetamide containing catalytic amounts of N-trimethylsilylimidazole followed by acylation with N-methyl bis(trifluoroacetamide). The serotonin concentrations in different rat tissues are determined by this method of selective omegaN-trifluoroacylation-1N-trimethylsilylation and compared with the values obtained by pertrimethylsilylation.     

共轭烯烃的分子几何构型、电子结构和生成热的DMM和AM1、PM3的比较研究

运用Ｄｅｌｆｔ分子力学（ＤＭＭ）力场和程序以及半经验分子轨道ＡＭ１和ＰＭ３方法计算研究了丁二烯、苯、甲苯、联苯、苯乙烯、富烯、、环辛四烯、［２，２］对环烷和菲等１０个共轭烯烃分子的几何构型、电子结构和生成热．ＤＭＭ计算的几何构型和生成热与实验结果相吻合，电荷分布结果与从头计算结果较接近．ＡＭ１和ＰＭ３计算的几何构型较好，但计算的生成热与实验结果偏差较大．ＰＭ３计算值比ＡＭ１的稍好．