高锰酸钾-甲醛-阿莫西林体系化学发光的研究及应用

在酸性介质中,高锰酸钾能氧化阿莫西林发生化学发光反应,而甲醛的存在可使发光强度增强。据此,采用流动注射技术,建立了一种测定阿莫西林的化学发光分析法。方法的检出限为3.0×10-8g/mL,相对标准偏差为1.52%(n=11,c=1.0×10-5g/mL),线性范围为5.0×10-8~2.0×10-5g/mL。该法已用于阿莫西林胶囊中阿莫西林含量的测定,结果满意。     

K3Fe(CN)6-钙黄绿素体系后化学发光反应测定盐酸氯丙嗪

发现了盐酸氯丙嗪在K3Fe(CN)6-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盐酸氯丙嗪的流动注射化学发光分析法.方法的检出限为3×10-8/mL,相对标准偏差为2.0%(2.0×10-6 g/mL盐酸氯丙嗪,n=11),线性范围为1.0×10-7～1.0×10-5 g/mL.此法已用于盐酸氯丙嗪片剂中盐酸氯丙嗪含量的测定,结果与药典方法测定值一致.     

流动注射化学发光分析法测定利福平

在酸性条件下,KMnO4能氧化利福平产生弱化学发光,并且,利福平能极大的增敏Na2SO3-KMnO4体系的化学发光信号。基于此,结合流动注射技术,建立了测定利福平的新方法。在优化的条件下,利福平在5.0×10-8g/mL~1.0×10-5g/mL范围内与化学发光强度呈良好的线性关系,检出限为3×10-8g/mL。对2.0×10-6g/mL的利福平进行11次平行测定,相对标准偏差为2.6%。该法用于胶囊和滴眼液中利福平的测定,并初步探讨了该化学发光反应机理。     

KMnO4-甲醛-茚三酮化学发光体系的研究

在甲醛存在下,KMnO4与茚三酮能够发生化学发光反应,产生很强的化学发光.据此采用流动注射技术,建立了一种利用KMnO4-甲醛-茚三酮化学发光体系测定茚三酮的方法.方法的检出限为3×10-8 g/mL;相对标准偏差为1.1%(4.0×10-6g/mL茚三酮,n=11);线性范围为1.0×10-7～2.0×10-4 g/mL.本法已用于样品中茚三酮的测定.     

流动注射-化学发光法测定富马酸依美斯汀

在酸性条件下,KMnO4与甲醛能够产生微弱的化学发光,而富马酸依美斯汀的存在能够大大增强该化学发光强度;结合流动注射技术,建立了测定富马酸依美斯汀的流动注射-化学发光新方法。该方法的线性范围分别为3.0×10-8～2.0×10-7g/mL,2.0×10-7～1.0×10-6g/mL和1.0×10-6～8.0×10-6g/mL。检出限为1.0×10-8g/mL,对2.0×10-6g/mL富马酸依美斯汀滴眼液平行测定11次,其相对标准偏差为1.3%。该方法已成功应用于滴眼液中富马酸依美斯汀的含量测定。     

流动注射化学发光法测定阿莫西林

在碱性介质中 ,阿莫西林抗生素对鲁米诺 KMnO4化学发光反应有增敏作用 ,据此建立了微量快速测定阿莫西林的流动注射化学发光分析法。该法线性范围为 1 .0× 1 0 -7～ 5 .0× 1 0 -5g mL ,检出限为 3.0× 1 0 -8g mL ;对 1 .0× 1 0 -6g mL阿莫西林 1 1次平行测定 ,其相对标准偏差为 1 .7%。此法已用于阿莫西林胶囊中阿莫西林的测定。     

高效液相色谱化学发光法测定血清中左羟丙哌嗪

在H2SO4介质中, KMnO4氧化左羟丙哌嗪产生化学发光, 甲醛可增敏上述化学发光, 在此基础上建立了反相高效液相色谱(RP-HPLC)分离, 柱后化学发光检测左羟丙哌嗪的新方法, 并成功应用于血清中左羟丙哌嗪的测定. 在优化的实验条件下, 该法测定左羟丙哌嗪的线性范围为1.0×10-7～1.0×10-5 g/mL, 检出限(3σ)为3×10-8 g/mL. 对2.0×10-6 g/mL的左羟丙哌嗪进行11次平行测定, 其相对标准偏差为2.3%.     

二溴荧光素-N-氯代丁二酰亚胺化学发光体系测定片剂及人血浆中的氢溴酸右美沙芬

研究发现,碱性溶液中,二溴荧光素可吸收N-氯代丁二酰亚胺(NCS)氧化氢溴酸右美沙芬反应的化学能而产生化学发光,从而构建了二溴荧光素-NCS-氢溴酸右美沙芬化学发光体系.利用该体系建立了测定氢溴酸右美沙芬的流动注射化学发光新方法.方法线性范围是9.0×10-10～2.0×10-7 g/mL(r=0.9992),检出限为7.0×10-10 g/mL,对2.0×10-8 g/mL氢溴酸右美沙芬溶液进行11次平行测定的相对标准偏差(RSD)为1.6%.该法已用于片剂及人血浆中氢溴酸右美沙芬含量的测定,结果令人满意.在对有关反应的动力学性质、化学发光光谱及有关物质的紫外吸收光谱和荧光光谱研究的基础上,推断出可能的反应机理.     

流动注射化学发光分析法测定利血平

研究发现在碱性介质中,利血平对Cr3 催化的Luminol-H2O2体系的化学发光有较强的抑制作用,据此建立了流动注射化学发光抑制法测定痕量利血平的新方法。该法线性范围宽,发光信号的降低值(ΔI)与利血平的质量浓度在1.0×10-8~2.0×10-5g/mL范围内呈良好的线性关系;检出限(3σ)为7.0×10-9g/mL;对于2.0~10-6g/mL利血平进行11次测定,相对标准偏差为1.8%。已用于针剂中利血平的测定。通过对化学发光光谱、紫外吸收光谱的研究,对机理进行了初步探讨。     

铁氰化钾-钙黄绿素体系后化学发光反应测定盐酸硫利达嗪

报道了盐酸硫利达嗪在铁氰化钾-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,并建立了一种利用后化学发光反应测定盐酸硫利达嗪的流动注射化学发光分析法。方法的检出限为2.0×10-7g/mL,对2.0×10-6g/mL盐酸硫利达嗪测定的相对标准偏差为2.0%(n=11),线性范围为5.0×10-7～5.0×10-5g/mL。该法已用于盐酸硫利达嗪片剂中盐酸硫利达嗪含量的测定,结果与药典方法测定值一致。     

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.