流动注射-[Cu(HIO6)2]5-配离子化学发光法测定兽药制剂中恩诺沙星

基于恩诺沙星对 [Cu(HIO6)2]5- 配离子-H3PO4 体系化学发光信号的增敏作用,提出了流动注射-化学发光测定恩诺沙星的新方法.考察了[Cu(HIO6)2]5- 配离子的光谱特性,优化了影响化学发光强度的条件.恩诺沙星质量浓度在4.0×10-8～1.0×10-5g/mL 范围内,化学发光强度与恩诺沙星的浓度之间呈现良好的线性关系.检出限为1.54×10-8g/mL,RSD为1.2%.方法已用于兽药制荆中恩诺沙星的测定,回收率为 90.0%～112%.     

流动注射-化学发光法测定非洛地平

基于非洛地平在碱性条件下对鲁米诺-K3Fe(CN)6化学发光体系具有很强的增敏作用,结合流动注射技术,建立了直接测定非洛地平的流动注射-化学发光新方法.方法的线性范围为6.0×10(-9)～3.0×10(-6)g/mL,检出限为2.1×10(-9)g/mL,对浓度为1.0×10(-7)g/mL非洛地平平行测定11次,其...     

纳米银催化的鲁米诺化学发光体系测定呋喃硫胺的研究

基于纳米银能够增强鲁米诺-H2O2-呋喃硫胺体系化学发光的现象,建立了测定呋喃硫胺的流动注射化学发光新方法.对体系的化学发光机理进行了初步探讨,发现该体系的化学发光光谱的最大发射波长为425nm,该体系的发光体为激发态的3-氨基邻苯二甲酸根离子.该方法测定呋喃硫胺的线性范围为1.0×10-8～1.0×10-5g/mL,检出限4×10-9g/mL,对1.0×10-6g/mL呋喃硫胺连续9次测定的相对标准偏差(RSD)为1.9％.方法已用于药物呋喃硫胺片中呋喃硫胺的测定.     

流通式化学发光传感器测定亚硫酸根

基于酸性介质中高锰酸钾氧化亚硫酸根产生化学发光,喹咛具有较强的增敏作用,设计出了流通式化学发光传感器。该传感器对亚硫酸根的线性响应范围为1.0×10-7～5.0×10-4g mL,检出限为5×10-8g mL,对1.0×10-6g mL的亚硫酸根进行11次连续测定,相对标准偏差为3.5%。从取样到测定的全部分析过程只需1min。作为分子识别和换能作用的离子交换柱,可连续使用200次以上。方法已用于啤酒中亚硫酸根的测定。     

反向流动注射化学发光法测定马来酸氯苯那敏

基于马来酸氯苯那敏对KIO4-鲁米诺化学发光体系有强的增敏作用,结合反向流动注射技术,建立了测定马来酸氯苯那敏的化学发光分析方法,在优化的条件下,测定马来酸氯苯那敏的线性范围为7.0×10-8~1.0×10-4g/mL,检出限为3×10-8g/mL,对质量浓度为9.0×10-7g/mL的马来酸氯苯那敏进行11次平行测定,其相对标准偏差为1.5%,方法已用于扑儿敏片剂和人体尿液中马来酸氯苯那敏的含量测定。     

纳米金催化鲁米诺化学发光体系测定甲巯咪唑

在碱性介质中,甲巯咪唑能强烈增敏纳米金-鲁米诺-硝酸银化学发光体系产生较强的化学发光信号,据此建立了一种流动注射化学发光测定甲巯咪唑的新方法。在优化实验条件下,该方法对甲巯咪唑的检测线性范围为1.0×10-9~1.0×10-8、1.0×10-8~1.0×10-7、1.0×10-7~1.0×10-6g/mL,检出限(S/N=3)为3.0×10-10g/mL,相对标准偏差为1.2%(n=11,ρ=1.0×10-8g/mL)。将该法用于药物中甲巯咪唑含量的测定,结果满意。同时,采用化学发光光谱表征技术对该体系的化学发光反应机理进行了初步探讨。     

流动注射化学发光法测定头孢克洛

研究发现在碱性条件下,头孢克洛对Luminol-H2O2体系的化学发光有较强的增敏作用,据此建立了流动注射化学发光测定头孢克洛药物的新方法。头孢克洛在1.0×10-8~2.0×10-5g/mL范围内与发光信号的增强值(ΔI)呈良好的线性关系;检出限(3δ)为6.0×10-9g/mL;对于1.0×10-6g/mL头孢克洛进行11次测定,相对标准偏差为2.2%。应用于希刻劳颗粒中头孢克洛的测定。     

流动注射-化学发光法测定亚胺培南的研究

在碱性条件下,亚胺培南对鲁米诺-K_3[Fe(CN)_6]化学发光体系具有增敏作用,据此,结合流动注射技术建立了一种测定亚胺培南的新方法。在最优的实验条件下,亚胺培南对化学发光的增敏强度与其浓度在4.0×10~(-8)~4.0×10~(-6) g/mL范围内呈现出良好的线性关系,检测限为1.1×10~(-8) g/mL,相对标准偏差为1.7%(n=11)。该方法可用于亚胺培南的测定,回收率为99.4%~101.8%。     

毛细管电泳-化学发光法测定人血清中的异烟肼

基于碱性介质中异烟肼对laminol-K3Fe(CN)6化学发光体系的增敏作用,设计了一个经毛细管电泳(CE)分离,在线化学发光检测异烟肼的新方法.研究并优化了毛细管电泳分离及化学发光检测的条件.在优化的实验条件下,该方法测定异烟肼的线性范围为4.0×10-7～1.0×10-5g/mL(R2=0.9984),检出限(3σ)为1×10-8g/mL,对6.0×10-6g/mL的异烟肼进行6次平行测定,其相对标准偏差为4.0%.方法已用于血清中异烟肼的测定.     

流动注射化学发光法测定盐酸普萘洛尔

在酸性条件下,KMnO4氧化盐酸普萘洛尔可产生化学发光,Fe2 的存在对于这一化学发光反应具有增敏作用,基于此建立了测定盐酸普萘洛尔的化学发光分析法。在选定的实验条件下,盐酸普萘洛尔的质量浓度在4.0×10-7～1.0×10-5g mL范围内与化学发光强度具有线性关系(相关系数为0.9992),检出限为1×10-7g mL盐酸普萘洛尔,相对标准偏差为2.9%(4.0×10-6g mL盐酸普萘洛尔,n=11)。该法已用于盐酸普萘洛尔片剂中盐酸普萘洛尔的测定,并与药典方法进行了对照。     

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%.     

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.     

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.     

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.     

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.     

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.