依诺沙星在混合粘合剂碳糊电极上的电化学特性

制备了混合粘合剂碳糊电极。在０．０１５ｍｏｌ／Ｌ，磷酸－０．１０ｍｏｌ／ＬＫＣｌ溶液中，依诺沙星在该电极上于－１．２６Ｖ处产生一灵敏的阴极溶出伏安峰。在－０．９０Ｖ富集９０ｓ后，依诺沙星的线性范围为３．１×１０＾－７－１．２×１０＾－５ｍｏｌ／Ｌ，检测下限为９．４２×１０＾－８ｍｏｌ／Ｌ，所提出的方法用于尿液和血清中依诺沙星测定，回收率在９６％－１０３％之间。     

混合粘合剂碳糊电极的制备及分析应用 Ⅱ.氯硝安定的溶出伏安法测定

本文提出用丙三醇－液体石腊混合粘合剂碳糊电极阴极溶出伏安法测定氯硝安定。在ｐＨ９．５的ＮＨ＿３－ＮＨ＿４Ｃｌ缓冲溶液中，氯硝安定在碳糊电极上于－０．７３Ｖ（Ｐ＿１）和－１．３３Ｖ（Ｐ＿２）处产生两个阴极溶出峰，利用Ｐ＿１峰可测定微量的氯硝安定。在８．０×１０￣（－８）～１．１×１０￣（－５）ｍｏｌ／Ｌ范围内，波高与浓度线性关系良好，检测Ｔ１民达４．０×１０，８ｍｏｌ／Ｌ。该法用于血清中氯硝安定测定，相对误差在１０％以内。     

哌仑西平的单扫描示波极谱法测定

本报道一种测定哌仑西平的单扫描示波极谱法，在０．１ｍｏｌ／ＬＮＨ４Ｃｌ－ＮＨ３．Ｈ２Ｏ（ｐＨ８．０±０．１）缓冲液中，哌仑西平有一极谱还原波，其峰电位为－１．５１Ｖ（ｖｓ．ＳＣＥ），其一阶导数峰高与哌仑西闰浓度在６．６×１０＾－７－４．６×１０＾－６ｍｏｌ／Ｌ（ｒ＝０．９９８１）和６．６×１０＾－６－１．６×１０＾－５ｍｏｌ／Ｌ（ｒ＝０．９９９１）范围内有线性关系，检测限为３．４×１０－７ｍｏｌ     

维生素K3亚硫酸氢钠的电化学研究

维生素Ｋ３亚硫酸氢钠在０．１ｍｏｌ／ＬＮａＣｌ＋０．０４ｍｏｌ／ＬＨＣｌ，ｐＨ＝１．８０底液中，于示波极谱仪上有一良好的二阶导数波，Ｅ″Ｐ＝－０．７４±０．０１Ｖ（ＳＣＥ），峰高与浓度在５×１０－９～１×１０－６ｍｏｌ／Ｌ以及１×１０－６～１×１０－５ｍｏｌ／Ｌ分段成线性关系，检测下限为１×１０－９ｍｏｌ／Ｌ，用于针剂含量的测定，结果良好。实验证明，当ｐＨ小于３．５９时，维生素Ｋ３亚硫酸氢钠逐渐转变为维生素Ｋ３亚硫酸，出现三个极谱峰，其中用于分析测定的峰为维生素Ｋ３亚硫酸１号位羰基的还原峰，其电极过程为扩散控制的可逆的双电子过程。     

脑益嗪的吸附伏安特性及其测定

在ｐＨ２．３的ＫＣｌ－ＨＣｌ底液中，脑益嗪在汞电极上有一还原峰。其导数峰电位为－１．４７Ｖ（ＳＣＥ）；线性范围１．０×１０＾－７～１．０×１０＾－６ｍｏｌ／Ｌ；最低检测限为１．０×１０＾－７ｍｏｌ／Ｌ。用多种电化学手段证明，脑益嗪的还原属于反应物弱吸附的不同逆过程。该法用于样品中脑益嗪含量的测定，结果令人满意。     

乳酸环丙沙星单扫描示波极谱法研究

研究了乳酸环丙沙星的极谱伏安行为，在ｐＨ＝８．３的０．０２ｍｏｌ／Ｌ，ＮＨ４Ｃｌ－ＮＨ３．Ｈ２Ｏ底液中，乳酸环丙沙星能产生１个灵敏的还原峰，峰电位为－１．６１Ｖ，其导数峰高与浓度在３．９×１０＾－８～１．８×１０＾－６ｍｏｌ／Ｌ和１．８×１０＾６～１．１×１０＾－５ｍｏｌ／Ｌ范围内呈现良好的线性关系，相关系数ｒ＝０．９９９７，检测下限为２．５×１０＾－８ｍｏｌ／Ｌ，用于乳酸环丙沙星注射液的测定，相     

邻苯三酚红修饰碳糊电极吸附伏安法测定痕量铋

报道了采用邻苯三酚红修饰碳糊电极测定痕量铋的方法。在０．３０ｍｏｌ／Ｌ的ＨＣｌ溶液中,于－０．１０Ｖ搅拌富集３ｍｉｎ,然后在－０．３５Ｖ静止还原６０ｓ,再进行阳极化扫描,在－０．１０Ｖ左右获得灵敏的铋溶出峰,二次导数民流与铋浓度在１．０＊１０＾－９－６．０＊１０＾－７ｍｏｌ／Ｌ范围内呈线性关系,同限为５＊１０＾－１０ｍｏｌ／Ｌ。对电极反应机理进行了讨论。     

丙酸睾丸素的吸附阴极溶出伏安法研究

在ｐＨ为６．０的Ｂ－Ｒ缓冲溶液中，丙酸睾丸素于电位－１．４Ｖ（ｖｓ．ＳＣＥ）左右处出现一个灵敏的附阴溶出峰。经５ｍｉｎ富集后，阴极溶出峰电流与浓度在１．３８×１０＾－＾８－７．３×１０＾－＾８ｍｏｌ／Ｌ范围内成线笥关系，该方法用于注射液中丙酸睾丸素含量测定，回收率８０％－８６％。检测下限为４．１×１０＾－＾９ｍｏｌ／Ｌ。     

铋—2,3,4—三羟基—4‘—磺基—偶氮苯配合物吸附波的研究

在０．０６ｍｏｌ／Ｌ柠檬酸钠－０．００３ｍｏｌ／Ｌ ＨＣｌ（ｐＨ６．５）介质中，２，３，４－三羟基－４＇－磺基－偶氮苯和铋产生灵敏的单扫描极谱导数峰，铋含量在０～６．７×１０＾－６ｍｏｌ／Ｌ范围内与波高成线性关系，检测限２．４×１０＾－８ｍｏｌ／Ｌ。用提出的方法测定了锡中的铋，并对反应机理进行了研究。     

铋－2，3，4－三羟基－4′－磺基－偶氮苯配合物吸附波的研究

在０．０６ｍｏｌ／Ｌ柠檬醚钠－０．００３ｍｏｌ／ＬＨＣ１（ｐＨ６．５）介质中，２，３，４－三羟基－４′－磺基－偶氮苯和铋产生灵敏的单扫描极谱导数峰，铋含量在０～６．７×１０￣（－６）ｍｏｌ／Ｌ范围内与波高成线性关系，检测限２．４×１０￣（－８）ｍｏｌ／Ｌ。用提出的方法测定了锡中的铋，并对反应机理进行了研究。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.