流动注射-化学发光法测定盐酸林可霉素

盐酸林可霉素在 Na IO4 - H2 O2 - H+体系中能发生强的化学发光反应 ,据此建立了一种测定盐酸林可霉素的流动注射 _化学发光分析法 ,方法的检出限为 3.6× 1 0 -8g/m L,相对标准偏差为 1 .0 % (c S=1 .0× 1 0 -6g/m L,n=1 1 ) ,线性范围为 1 .0× 1 0 -7～ 9.0× 1 0 -5g/m L。该方法已用于盐酸林可霉素注射液的分析     

流动注射化学发光法测定DL-酪氨酸

在甲醛存在下 ,高锰酸钾与DL 酪氨酸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 ,建立了一种测定DL 酪氨酸的化学发光分析法。方法的检出限为 2 .9× 1 0 - 8g/mL ,相对标准偏差为 1 .5 % ( 1 .0× 1 0 - 6g/mLDL 酪氨酸 ,n =1 1 ) ,线性范围为 1 .0× 1 0 - 7g/mL～ 5 .0× 1 0 - 6g/mL。     

高锰酸钾-甲醛-碘化学发光新体系的研究

在甲醛存在下 ,高锰酸钾在酸性溶液中可以氧化碘离子 ,产生很强的化学发光。根据这一发现 ,采用流动注射技术 ,建立了利用高锰酸钾 -甲醛 -碘化学发光体系测定碘的化学发光分析法。方法的检出限为 1 .8× 1 0 -8g/m L,相对标准偏差为 1 .3% (1 .0× 1 0 -6g/m L ,n=1 1 ) ,线性范围为 1 .0× 1 0 -7～ 8.0× 1 0 -6g/m L。方法已用于食品中碘含量的测定。     

反向流动注射化学发光法测定盐酸乙胺丁醇

基于盐酸乙胺丁醇与高碘酸钾～鲁米诺反应产生很强的化学发光,结合反向流动注射技术,建立了流动注射化学发光法测定盐酸乙胺丁醇的新方法。在优化的实验条件下,该法的线性范围为4.0×10-8～2×10-5g/mL,检出限为8×10-9g/mL,对6.0×10-7g/mL盐酸乙胺丁醇进行11次平行测定,方法的相对标准偏差为1.9%。该法可用于片剂中盐酸乙胺丁醇的测定。     

流动注射化学发光法测定盐酸吗啉胍

二氯荧光素作为能量转移剂,N 溴代丁二酰亚胺氧化盐酸吗啉胍产生化学发光,十六烷基三甲基氯化铵对该体系具有强烈的增敏作用,据此建立了测定盐酸吗啉胍的流动注射化学发光分析法。研究了影响化学发光的各种因素,对机理进行了探讨。方法对盐酸吗啉胍响应的线性范围为 1. 0×10-5 ~0. 1g/L,检出限(3σ)为 3. 0×10-6 g/L,RSD为 2. 5% (5. 0×10-4 g/L,n=11)。本法用于盐酸吗啉胍片及杀菌剂中盐酸吗啉胍的定量分析,结果满意。     

高锰酸钾-甲醛-尿酸化学发光体系的研究

在甲醛存在下,高锰酸钾与尿酸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,建立了一种利用高锰酸钾甲醛尿酸化学发光体系测定尿酸的化学发光分析法。方法的检出限为6×10-6 g/L;相对标准偏差为1. 8% (4. 0×10-4 g/L尿酸,n=11 );线性范围为2. 0×10-5 ~5. 0×10-3g/L。本法用于人体尿液中尿酸的测定,结果令人满意。并探讨了反应机理。     

电生次氯酸根流动注射化学发光法测定L-多巴

将恒电流电解产生ClO~-与流动注射化学发光分析法结合,基于L多巴对ClO~-Luminol体系化学发光的抑制作用,建立了测定L多巴流动注射化学发光新分析法.该法测定L多巴的检出限为8×10~(-10)g/mL,线性范围为2×10~(-9)～1×10~(-7)g/mL,相对标准偏差为3.0%.该法具有简单、快速、灵敏的特点,应用于药片中L多巴的测定,结果满意.     

测定甲氨喋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1×10μg/L,相对标准偏差为2.1 %(8×10μg/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     

流动注射化学发光法测定安痛定注射液中的氨基比林

在甲醛存在下 ,高锰酸钾与氨基比林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测定氨基比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 1.3 % (4 .0× 10 -6g/mL氨基比林 ,n =11) ,线性范围为 1.0× 10 -7～ 8.0× 10 -5g/mL氨基比林。该法已用于安痛定注射液中氨基比林含量的测定。     

锰C-抗坏血酸甲醛-化学发光体系的研究

实验观察到锰 氧化抗坏血酸可以产生弱的化学发光 ,甲醛对这一化学发光反应有较强的增敏作用 ,据此建立了测定抗坏血酸的流动注射化学发光分析法。方法的检出限为 2× 1 0 -8mol/L抗坏血酸 ;线性响应范围为 6 .0× 1 0 -8～ 2 .0× 1 0 -5mol/L。对 1 .0× 1 0 -6mol/L的抗坏血酸进行 1 1次测定 ,相对标准偏差为 2 3%。该方法已成功应用于维生素C针剂和片剂中抗坏血酸含量的测定 ,结果与药典方法测得值一致     

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%.     

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.     

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.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

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 novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.