改良型比光谱-导数分光光度法在四元混合体系同时测定中的应用

提出了可应用于四元混合体系同时测定的比光谱-导数分光光度法,阐述了该方法的基本原理,并将其应用于氨基比林、苯巴比妥、咖啡因和非那西丁四元混合体系中各组分的同时测定.结果表明,氨基比林、苯巴比妥、咖啡因和非那西丁的回收率分别是109.3%(RSD=4.3%)、102.4%(RSD=6.6%)、108.7%(RSD=5.1%)、98.62%(RSD=3.2%).方法的准确度和精密度都可以满足四组分同时测定的要求,方法简单、快速.     

三重-比导数分光光度法同时测定氨基比林、非那西丁和咖啡因含量的研究

阐述了三重-比导数分光光度法同时测定氨基比林、非那西丁和咖啡因的基本原理,并研究了实验条件。试验结果表明,氨基比林的平均回收率为103.3%,相对标准偏差(RSD)为2.3%(n=13);非那西丁的平均回收率为99.44%,RSD为1.2%(n=13);咖啡因的平均回收率为98.41%,RSD为1.1%(n=13)。     

回归正交设计分光光度法测定克敏感片各组分含量

本文提出了克敏感片中氨基比林、非那西丁、咖啡因和扑尔敏四组分回归正交设计分光光度法同时测定的新方法，比ＡＫＣ法和ＣＡＰ法更简便，快速、准确。     

回归正交设计分光光度法测定克感敏片各组分含量

本文提出了克感敏片中氨基比林、非那西丁、咖啡因和扑尔敏四组分回归正交设计分光光度法同时测定的新方法，比ＡＫＣ法和ＣＰＡ法更简便、快速、准确。     

BP网络光度法测定去痛片中的四组分

应用Levenberg-Marquardt优化算法的BP网络,采用紫外分光光度法测定去痛片中四组分的含量。测定低含量组分咖啡因和苯巴比妥时,结合吸光度减法技术。氨基比林、非那西丁、咖啡因和苯巴比妥的平均回收率和RSD分别为99.3%,1.2%：;100.0%,1.1%;100.3%,1.5%;100.1%,1.3%。     

统计模拟分光光度法同时测定复方茶碱片中的五组分含量

研究了测定复方茶碱片中五组分含量的统计模拟分光光度法。利用逐步回归分析法建立经验数学模型。再运用改良单纯形法进行优化，同时测定复方茶碱片中的五种组分-氨基比林、非那西丁、茶碱、可可碱和咖啡因的含量，其回收率分别为99.5%、100.2%、101.2%、100.2%和99.2%，RSD分别为1.51%、1.03%、4.44%、2.47%和3.12%。t检验结果证明，该方法与HPLC法之间无显著性差异。     

混合线性分析法同时测定安痛定注射液中三组分含量

将一种新近发展的多元校正方法——混合线性分析法，用于安痛定注射液中氨基比林、安替比林、巴比妥含量的同时测定。在220～250nm内取16个波长测量7组标准混合溶液的吸光度矢量作为校正集，以最小二乘法求得系数矢量作为各组分的纯光谱，用混合线性分析法进行数据处理。氨基比林、安替比林、巴比妥的标准回收率分别为99．0％～100．3％、99．0％～100．8％和98．5％～101．1％。用于安痛定注射液中氨基比林、安替比林、巴比妥三组分含量的测定，经t检验，其测定结果与标准法相比，两者间无显著性差异。     

多波长线性回归紫外分光光度法同时测定复方阿斯匹林片中的三组分

用改进的多波长线性回归分光光度法同时测定了复方阿期匹林片中三组分的含量,模拟样品中阿斯匹林、非那西丁、咖啡因的平均回收率分别为１００．３１％、９９．８７％、１００．７７％,相对标准偏差分别为０．３５％、０．２５％、１．３７％（ｎ＝１０）。对四个批号实际样品的测定结果与标准方法一致,适物复方阿斯匹林片的常规分析。     

GC法同时测定酚氨咖敏片中4种组分

建立了同时测定酚氨咖敏片中对乙酰氨基酚、氨基比林、咖啡因和马来酸氯苯那敏4组分含量的毛细管气相色谱法。采用SE-30大口径毛细管色谱柱(30 m×0.53 mm,1.0μm),柱温190℃,汽化室温度220℃,检测器为FID,检测温度250℃,载气为高纯N2,分流比为1∶6,内标为盐酸麻黄碱,以无水乙醇为溶剂,样品无需衍生化处理,直接进样测定。样品中各组分完全分离,辅料无干扰,对乙酰氨基酚、氨基比林、咖啡因和马来酸氯苯那敏分别在20~2000μg/mL、15~1500μg/mL、10~500μg/mL和20~100μg/mL范围内线性关系良好(r0.999),各组分的平均回收率在99.6%~101.2%范围内,RSD2%。     

基于VB的岭回归法测定扑热息痛等五组分含量的研究

将岭回归吸光光度法（LHG）应用于感冒液中扑热息痛,扑尔敏,咖啡因,愈创木酚甘油醚和对氮基酚等五组分含量的同时测定,运用VB语言进行程序设计。试验结果表明,该法样品各组分的平均回收率在97．9％－103．3％之间,样品不经分离即可测定,取得了满意的分析结果。     

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.