AuCl_4~--鲁米诺体系测定氨苄西林钠

在NaOH介质中, AuCl4-氧化鲁米诺产生化学发光, 氨苄西林钠显著增强该体系的发光. 据此, 建立了一种测定氨苄西林钠的流动注射化学发光新方法. 在优化的实验条件下, 该法测定氨苄西林钠的线性范围为0.01～10 μg/mL, 检出限为4.0 ng/mL, 对1.0 μg/mL 氨苄西林钠进行了11次测定, 其相对标准偏差为1.4%. 用于粉针剂、合成样品及尿样中氨苄西林钠的测定.     

化学发光法同时测定色氨酸和半胱氨酸的研究

基于色氨酸和半胱氨酸对Ru(pheo)32 -Ce(Ⅳ)体系化学发光的增强作用及其发光动力学性质的显著差别,提出了一种化学发光法同时测定这两种氨基酸的新方法.在优化的实验条件下,该方法测定色氨酸和半胱氨酸的线性范围分别为0.05～2.0 μg/mL和0.05～3.0 μg/mL,检出限分别为0.03 μg/mL和0.02 μg/mL.将其应用于合成样品中两种氨基酸的同时测定.结合文献提出了可能的化学发光反应机理.     

AuCl_4~--鲁米诺体系测定阿莫西林钠的含量

在NaOH介质中,AuCl4-氧化鲁米诺产生化学发光,阿莫西林钠显著增强该体系的发光,据此建立了测定阿莫西林钠的流动注射化学发光新方法.在优化的实验条件下,测定阿莫西林钠的线性范围为0.01～15 μg/mL,检出限为2.6 ng/mL,对1.0 μg/mL阿莫西林钠进行了11次平行测定,其相对标准偏差为1.7%.本法已用于针剂及血清中阿莫西林钠的测定.     

荧光素-牛血清白蛋白的化学发光反应研究

研究了在碱性介质和阳离子表面活性剂CTMAB存在下,NaClO氧化荧光素-牛血清白蛋白的化学发光行为和化学发光反应的条件,提出了反相流动注射化学发光测定牛血清白蛋白的新方法.该法测定牛血清白蛋白的线性范围为0.02～6.4 μg/mL,检出限为0.005μg/mL.     

鲁米诺-AuCl4体系化学发光法测定美洛西林钠

在NaOH介质中, AuCl4-氧化鲁米诺产生化学发光, 美洛西林钠显著增强该体系的发光, 据此建立了一种测定美洛西林钠的流动注射化学发光新方法. 在优化的实验条件下, 该法测定美洛西林钠的线性范围为0.01～30 μg/mL, 检出限为3.0 ng/mL, 对1.0 μg/mL美林钠进行了11次平行测定, 其相对标准偏差为1.0%. 方法已用于生物体液和粉针剂中美洛西林钠的测定.     

鲁米诺-过氧化氢化学发光体系分析环吡酮胺及其制剂

在碱性介质中,环吡酮胺对H2O2氧化鲁米诺化学发光体系有较强的增敏作用,据此建立了流动注射-化学发光测定环吡酮胺的新方法,显著地提高了检测灵敏度.在优化的试验条件下,发光信号的增敏值(△I)与环吡酮胺溶液的浓度ρ在0.25～4.0μg/mL范围内线性关系良好,检出限为0.06 μg/mL.对浓度为1 μg/mL环吡酮胺...     

ClO--鲁米诺流动注射-抑制化学发光法测定银杏黄酮

基于在碱性条件下,银杏黄酮对ClO--鲁米诺体系有显著的抑制作用,结合反相流动注射技术,建立了流动注射-抑制化学发光测定银杏提取物中的银杏黄酮.银杏黄酮质量浓度在0.4～14.0 μg/mL范围与相对发光强度呈线性关系,检出限为0.06 μg/mL,采样频率为120次/h,对10.0 μg/mL的银杏黄酮平行测定11次,其RSD为1.2%,回收率为98.0%～104%.该方法可用于银杏黄酮制剂的测定.     

流动注射化学发光法测定盐酸曲马多

基于盐酸曲马多对酸性介质中高锰酸钾与亚硫酸钠间弱化学发光反应的显著增强作用,建立了一种流动注射化学发光法测定曲马多的新方法.并用荧光、紫外和化学发光光谱探讨了曲马多对这一体系增敏作用的机理.在优化的实验条件下,化学发光强度与曲马多的浓度在0.04～4.0 μg/mL内呈线性关系,相关系数为0.9995,检出限为0.01μg/mL.平行测定曲马多11次的相对标准偏差为2.1%.用本法对盐酸曲马多注射液中曲马多进行了测定,结果满意.     

测定甲氨蝶呤的在线电生次氯酸根流动注射化学发光法

将在线恒电流电解产生ClO-与流动注射化学发光分析法结合, 基于甲氨蝶呤对ClO--鲁米诺体系化学发光的抑制作用, 建立了测定甲氨蝶呤流动注射化学发光新方法. 该法测定甲氨蝶呤质量浓度的线性范围为2×10 ～ 4×102 μg/L, 检出限为1×10 μg/L, 相对标准偏差为2.1%(8×10 μg/L, n=9), 已应用于片剂和针剂中甲氨蝶呤的测定. 该法具有简单、快捷、灵敏等特点.     

流动注射后化学发光法测定Ca~(2+)

实验发现Ca2+在铁氰化钾-钙黄绿素化学发光反应体系中的后化学发光反应.优化了反应条件,建立了一种利用后化学发光反应测定Ca2+的流动注射化学发光分析法.方法的线性范围为1.0×10-6～1.0×10-4 g/mL,检出限为3.0×10-7 g/mL, 相对标准偏差为1.8%(2.0×10-5 g/mL Ca2+,n=11).此法已用于自来水中Ca2+含量的测定,结果与标准方法测定值一致.     

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.