流动注射后化学发光法测定异烟肼

本文发现了异烟肼在铁氰化钾-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异烟肼的流动注射化学发光分析法。方法的检出限为6×10-8g/mL, 相对标准偏差为1.8% (2.0×10-6 g/mL 异烟肼,n=11）,线性范围为2.0×10-7~1.0×10-5 g/mL。此法已用于异烟肼片剂中异烟肼含量的测定,结果与药典方法测定值一致。     

流动注射电化学发光测定利福平的研究

发现利福平对电生BrO-氧化Luminol的强化学发光有很强的抑制作用。将在线恒电流电解产生BrO-与流动注射技术结合,建立了流动注射电化学发光测定利福平的新方法。该方法线性范围为1×10-8～1×10-6g/mL,检出限为3×10-9g/mL,相对标准偏差为1.7%(n=11,c=2.0×10-7g/mL)。     

流动注射化学发光法测定褪黑素

在强碱性介质中,铁氰化钾可直接氧化褪黑素产生化学发光。基于此,建立了一种测定褪黑素的流动注射化学发光分析方法。线性范围为1.9×10-6~2.3×10-4g/mL,检出限为5×10-7g/mL,该法已用于药物中褪黑素的测定。     

流动注射阻抑化学发光法测定己烯雌酚

基于在碱性介质中,己烯雌酚对N-溴代丁二酰亚胺-鲁米诺化学发光体系的阻抑作用,建立了测定己烯雌酚的流动注射化学发光分析新方法,探讨并优化了流动注射化学发光的分析条件。该方法测定己烯雌酚的线性范围为1.5×10-8~2.6×10-7g/mL,检出限为5.0×10-9g/mL,对1.0×10-7g/mL的己烯雌酚标准溶液进行11次测定,相对标准偏差为2.6%。并应用于饲料、己烯雌酚片剂中的己烯雌酚的测定。     

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。     

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.     

鲁米诺-8-羟基喹啉-5-磺酸-镉(Ⅱ)-过氧化氢化学发光体系研究

报道了Cd(Ⅱ)对鲁米诺-8-羟基喹啉-5-磺酸-过氧化氢体系的化学发光具有增强作用的实验事实,建立了测定Cd(Ⅱ)的分析方法.该法线性范围为2.0×10~(-8)～1.0×10~(-6)g/mL;相对标准偏差为3.5%;检出限为1.0×10~(-8)g/mL.用于合金样品中Cd(Ⅱ)的分析,结果良好.     

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。     

罗丹明B-过氧乙酸-氢氧化钠化学发光法测定痕量硫

基于硫离子对罗丹明B 过氧乙酸 NaOH化学发光有较强的增敏作用,建立了流动注射化学发光增强法测定痕量硫的新方法。该法的线性范围为3.0×10-8～8.0×10-7g/mL,检出限为3.5ng/mL,相对标准偏差为2.2%(1.0×10-7g/mLS2-,n=11)。此法已用于环境水样中痕量硫的测定。     

流动注射结合化学发光法测定没食子酸

基于没食子酸与铬 (Ⅵ )的氧化还原反应 ,产生的铬 (Ⅲ )催化鲁米诺 H2 O2 化学发光体系的研究 ,结合流动注射技术 ,优化反应条件 ,建立了一种高灵敏度的快速测定没食子酸的新方法。方法的线性范围为 2 .0× 1 0 - 9～ 5 .0× 1 0 - 6g/mL ,检出限为 1 .2× 1 0 - 9g/mL ,对 1 .0× 1 0 - 7g/mL的没食子酸进行了 1 1次平行测定 ,相对标准偏差为 2 .1 %。方法成功地用于健民咽喉片中没食子酸的测定。     

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.