奎宁与氯冉酸的胶束增敏荷移反应及其测定

提出了一种基于胶束增敏荷移反应测定奎宁的光度分析法。研究了在阳离子表面活性剂氯化十六烷基吡啶 (CPC)胶束体系中电子给体奎宁与电子受体氯冉酸之间的荷移反应产物的光谱性质。发现CPC对奎宁与氯冉酸的荷移反应络合物的光吸收有显著的增强作用 ,使络合物的表观摩尔吸光系数提高了 2 .5倍(λmax=5 2 0nm ,ε=3.6 4× 1 0 3 L·mol-1 ·cm-1 )。奎宁浓度在 2 0～ 80 0mg/L范围内符合比耳定律 ,r =0 9991。本方法用于片剂中奎宁含量的测定 ,其回收率为 97.3%～ 99.2 % ;5次测定的相对标准偏差为 1 .6 %～ 2 5 %。     

克霉唑与氯冉酸的荷移反应及其测定

克霉唑与氯冉酸在丙酮介质中发生电荷转移反应 ,生成 1∶1型络合物 ,该络合物的λmax=5 2 5nm ,表观摩尔吸光系数是 1.2 2× 10 3 L·mol-1·cm-1,药物浓度在 0～ 30 0mg/L范围内符合比耳定律 ,6次测定的相对标准偏差为 1.4 % ,回收率在 97%以上。用拟定的方法测定药物片剂中有效成分的含量 ,结果与药典方法相符     

荷移分光光度法测定扑尔敏

1引言扑尔敏又称马来酸氯苯那敏,为抗组织胺药,对各种过敏性疾病有良好的疗效。本文首次利用扑尔敏与氯冉酸在丙酮介质中发生的荷移反应,建立简便的分光光度法,对扑尔敏制剂中的有效成分进行含量测定。测定波长是536nm,表观摩尔吸光系数是1．38×103L·mol－1·cm－1,线性范围是20－280mg／L,回收率在98％以上。用本方法和药典方法对制剂进行含量测定,结果相符。2实验部分2．1主要仪器与试剂721分光光度计（上海第三分析仪器厂）。1g／L扑尔敏（药物纯）丙酮溶液;3×10－3mol／L氯冉酸（分析纯）丙酮溶液;所用其它试剂均为分析…     

钍-氨基 G 酸偶氮氯膦-氯化十四烷基吡啶显色反应的研究及应用

在2N盐酸溶液中,钍(Ⅳ)与氨基G酸偶氮氯膦及氯化十四烷基吡啶形成蓝绿色三元络合物,最大吸收波长为698nm,摩尔吸光系数为1.88×10~6·1·mol~(-1)·cm~(-1)。三元络合物中钍与氨基G酸偶氮氯膦组成比为1:2,多数常见共存元素允许量较大,方法选择性好,可用于矿石中微量钍的测定。     

阿苯达唑与氯冉酸的荷移反应与应用

研究并确定了阿苯达唑与氯冉酸的荷移反应条件。在乙醇丙酮介质中形成１∶１络合物,其λｍａｘ＝５２５　ｎｍ,吸光度与阿苯达唑浓度在０～２８０　ｍｇ／Ｌ范围内呈线性关系;表观摩尔吸光系数为８．０３×１０３Ｌ·ｍｏｌ－１·ｃｍ－１;桑德尔灵敏度为０．０３３　μｇ·ｃｍ－２;相对标准偏差小于１％（ｎ＝８）,回收率符合要求。     

电荷转移络合物分光光度法测定磺胺脒的研究

研究了电子给体磺胺脒与电子受体对苯醌之间的荷移反应。结果表明 ,在乙醇介质中磺胺脒与对苯醌能形成橙红色电荷转移络合物 ,且反应体系的pH范围较宽。络合物的最大吸收波长λmax=497.6nm ,表观摩尔吸光系数为 2 .3 5× 1 0 3L·mol- 1 ·cm- 1 ,比耳定律的线性范围是 0～ 5 0mg/L ,络合比为 1∶2。应用拟定的方法测定磺胺脒制剂的含量 ,平均回收率为 1 0 0 .4% ,可用于磺胺脒制剂的分析。     

克拉霉素与紫色素的荷移反应及其测定

建立了一种测定克拉霉素的荷移分光光度法。克拉霉素与紫色素在乙醇溶液中发生电荷转移反应,荷移络合物在548nm处有最大吸收,表观摩尔吸光系数是4.49×103L·mol-1·cm-1,该络合物的组成是1∶1;稳定常数是3.48×104;药物浓度在10~150mg/L范围内服从比耳定律。当克拉霉素浓度为100mg/L时,6次测定结果的相对标准偏差为1.2%。利用本法测定了克拉霉素制剂中有效成分的含量,并与文献法进行比较,二者结果基本吻合,回收率在97.0%以上。     

罗红霉素与紫色素的荷移反应及其测定

建立了一种测定罗红霉素的方便而快捷的荷移分光光度法。罗红霉素与紫色素在乙醇介质中发生电荷转移反应 ,荷移络合物在 5 4 4nm处有最大吸收 ;表观摩尔吸光系数是 6 .5 6× 10 3L·mol- 1 ·cm- 1 ,该络合物的组成是 1∶1,稳定常数是 3× 10 4 。药物浓度在 0～ 12 0mg L范围内服从比耳定律。当罗红霉素浓度为 5 0mg L时 ,5次测定结果的相对标准偏差为 1.3%。利用本法测定了罗红霉素胶囊中有效成分的含量 ,并与文献法进行比较 ,二者结果基本吻合 ,回收率在 96 %以上。     

荷移反应及其在分析化学中的应用：（四）双氢氯噻嗪测定方法研究

本文研究了双氢氯噻嗪与四氯苯醌之间的荷移反应.结果表明:在碱性水醇介质中双氢氯噻嗪与四氯苯醌形成1:1络合物,其λ_(max)=335nm,摩尔吸光系数ε=3.65×10~4L·mol~(-1)·cm~(-1),相对标准偏差为1.2％(n=10)。应用拟定的方法测定药物制剂含量与药典方法一致。回收率在95％以上。     

氯冉酸荷移分光光度法测定尿样中盐酸非索非那定

建立了氯冉酸荷移分光光度法测定盐酸非索非那定含量的新方法。结果表明:盐酸非索非那定和氯冉酸在正丙醇介质中形成稳定的1∶1型荷移络合物,并在529nm波长处有最大吸收,表观摩尔吸光系数为3.3×103 L·mol-1·cm-1,盐酸非索非那定质量浓度在0.2～100mg·L-1范围内符合比耳定律,相关系数R=0.9974,检出限为0.12mg·L-1。该法用于尿样及药片中盐酸非索非那定含量的测定,其回收率为99.87%～101.2%。     

协同增敏荧光光度法在双嘧达莫分析中的应用

用荧光光度分析法研究了三羟甲基氨基甲烷和十二烷基硫酸钠对双嘧达莫的协同荧光增敏作用,提出了在此条件下测定双嘧达莫的协同荧光增敏光度法。方法灵敏度高,检出限低(9.20×10-9mol·L-1),在 7.927×10-8~2.378×10-6 mol·L-1范围内荧光强度与双嘧达莫的浓度呈良好线性关系。     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

Cu0-catalysed 1,3-dipolar cycloadditions of α-amino acid derived N,N-cyclic azomethine imines to ynones

A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu⁰ as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than Cu^I in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT).