H2-受体拮抗剂的流动注射-化学发光分析方法的研究

碱性介质中K3Fe（CN）6与H2-受体拮抗剂发生氧化-还原反应产生化学发光,罗丹明6G可显著增强其发光信号,且强度与药物浓度呈良好的线性关系。据此,建立了采用K3Fe（CN）6-罗丹明6G体系测定制剂中H2-受体拮抗剂的流动注射-化学发光分析方法。在优化的实验条件下,西咪替丁在1.0×10^-9-7.0×10^-5g/mL范围内呈良好的线性关系,检出限为8.6×10^-10g/mL;盐酸雷尼替丁在1.0×10^-9-5.0×10^-5g/mL范围内呈线性关系,检出限为8.7×10^-10g/mL;法莫替丁在5.0×10^-9-7.0×10^-5g/mL范围内呈线性关系,检出限为2.4×10^-9g/mL。通过对浓度为1.0×10^-6g/mL的3种H2-受体拮抗剂分别进行的11次平行测定,其RSD分别为4.0%,3.8%和2.9%。     

地塞米松磷酸钠的流动注射-化学发光分析法的研究

实验了地塞米松磷酸钠在K3Fe（CN）6-鲁米诺、KMnO4-鲁米诺、KIO4-鲁米诺、H2O2-鲁米诺体系中的化学发光现象。结果表明,地塞米松磷酸钠能够显著增强K3Fe（CN）6-鲁米诺体系和KMnO4-鲁米诺体系的化学发光强度,而在另外两个体系中没有增强作用。结合流动注射技术,分别在K3Fe（CN）6-鲁米诺体系和KMnO4-鲁米诺体系中建立了测定地塞米松的新方法。方法的线性范围分别为1.0×10^-7-1.0×10^-5g/mL和6.0×10^-8-1.0×10^-5g/mL,检出限分别为3.0×10^-8g/mL和2.0×10^-8g/mL,相对标准偏差分别为1.6%和1.9%（1.0×10^-6g/mL地塞米松,n=11）。此法已用于针剂和片剂样品的测定,结果与药典方法没有显著性差异。     

盐酸倍他司汀对鲁米诺-高碘酸钾体系后发光作用机理的探讨及其快速测定

实验发现盐酸倍他司汀对鲁米诺-高碘酸钾发光体系具有后化学发光作用，并对其作用机理进行了探讨。结合流动注射技术，优化了反应条件，并建立了测定盐酸倍他司汀的新方法。该方法简便、快速、准确，线性范围为2.0×10^-7－4.0×10^-4mol／L（r=0.9975），检出限为1.0×10^-7mol／L；对4.0×10^-5mol／L的盐酸倍他司汀进行了11次平行测定，相对标准偏差为2.9％。方法成功地用于盐酸倍他司汀片中盐酸倍他司汀的测定。     

吐温-40-高碘酸钾-过氧化氢化学发光体系测定中药五倍子中的单宁酸

基于单宁酸对过氧化氢和高碘酸钾溶液在温温-40存在下化学发光反应的增敏作用,结合流动注射技术,建立测定痕量单宁酸化学发光的方法,测定单宁酸的线性范围为5．0×10^-8～1．0×10^-5mol·L^-1;检出限为2．3×10^-1mol·L^-1;对于5.0×10^-6mol·L^-1单宁酸进行11次平行测定,其相对标准偏差为2．6％。对化学发光反应的机理也作了初步探讨。     

在线分子印迹-化学发光法对食品中苏丹红Ⅰ的测定

以苏丹红Ⅰ作模板分子,用悬浮聚合法制备出微米级苏丹红Ⅰ分子印迹聚合物并将其做成微固相萃取柱,直接安装在流动注射系统的八通阀上,对样品溶液中的苏丹红Ⅰ进行在线分离和富集;经甲醇和甲酸混合洗脱液（体积比2：1）在线洗脱后与酸性高锰酸钾发生化学发光反应。据此建立了在线分子印迹微固相萃取,高锰酸钾氧化苏丹红化学发光测定食品中苏丹红Ⅰ的新方法。结果表明,测定的苏丹红Ⅰ线性范围为1．0×10^-6～7．0×10^-4g／L,方法检出限（3仃）为3×10^-7g／L,11次平行测定1×10^-5g／L苏丹红Ⅰ溶液的化学发光强度相对标准偏差为2．0％。     

毛细管电泳电化学发光法测定盐酸帕罗西汀的研究

实验发现盐酸帕罗西汀能增强钌联吡啶的电化学发光信号,据此建立了一种盐酸帕罗西汀的毛细管电泳-电化学发光测定新方法。在实验中,分别对毛细管电泳分离条件和电化学发光检测条件进行了优化。在优化的实验条件下,盐酸帕罗西汀检出限为3.45×10^-8g/mL（S/N=3）,线性范围为3.0×10^-7-1.0×10^-4g/mL。通过对1.0×10^-5g/mL的盐酸帕罗西汀进行11次平行测定,峰高的RSD为2.5%。已用于盐酸帕罗西汀片剂的测定。     

流动注射化学发光法测定黄藤素

碱性条件下,铁氰化钾氧化鲁米诺产生化学发光,黄藤素对该体系的化学发光信号具有显著的增强作用。基于此,建立了一种直接测定黄藤素的流动注射化学发光分析新方法。该方法的线性范围为6.0×10-10－3.0×10^-8mol／L（r=0.9956）和3.0×10^-8－3.0×10^-6mol／L（r=0.9981）,检出限为2.5×10^-10mol／L（3σ）。对1.0×10^-9mol／L和1.0×10^-7mol／L的黄藤素连续平行测定11次,其相对标准偏差分别为3.5％和0.73％。该方法用于药物和体液中黄藤素的分析,回收率在96％-102％之间。     

流动注射化学发光法测定青霉胺

在酸性条件下高碘酸钠氧化过氧化氢产生弱发光,青霉胺的加入能大大增强此弱发光,据此,建立了流动注射化学发光法测定青霉胺的方法。该方法的线性范围为1．0×10^-6～8．0×10^-4mol·L^-1,检出限为5．6×10^-7mol·L^-1,对8．0×10^-5mol·L^-1的青霉胺进行7次平行测定,其相对标准偏差为1．9％。已应用于青霉胺片中青霉胺含量的测定,结果与中国药典法测得值一致。在青霉胺片中加入6×10^-5～2×10^-4mol·L^-1青霉胺标准进行回收试验,测得回收率在97．8％～104．4％之间。对化学发光反应的化学机理也作了简要探讨。     

流动注射化学发光法测定甲磺酸帕珠沙星

在酸性条件下甲磺酸帕珠沙星（Pazufloxacin Mesylas）对Ce（Ⅳ）-Na2SO3弱化学发光体系具有很强的增敏作用,据此建立了流动注射化学发光法测定甲磺酸帕珠沙星的新方法。该方法的线性范围为1.0×10^-2-7.0 mg/L,检出限为2.0×10^-3mg/L,相对标准偏差RSD（n=11,ρ=1.0 mg/L）为1.7%,回收率为94%-101%。已用于NaCl注射液中甲磺酸帕珠沙星的测定。     

氯酚红分光光度法测定盐酸吡格列酮

在pH9.40的Britton-Robinson广泛缓冲溶液中,氯酚红与盐酸吡格列酮反应,形成离子缔合物,其最大褪色波长位于570 nm处,最大增色波长位于434 nm处。盐酸吡格列酮的浓度分别在1.3×10^-6-1.1×10^-5mol/L和1.5×10^-6-1.2×10^-5mol/L范围内遵守比耳定律,表观摩尔吸光系数分别为4.29×10^4L.mol^-1.cm^-1和1.47×104L.mol^-1.cm^-1,检出限分别为3.50×10^-7mol/L和6.54×10^-7mol/L,回收率为100.8%-101.4%（血样）、99.3%-99.8%（混合样）、98.1%-98.6%（尿样）。方法已用于血样、尿样和混合样中盐酸吡格列酮测定。     

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.     

A carbanion induced synthesis of highly congested pyrazole and imidazole containing heterocycles

An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.     

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.     

Selective synthesis of 4,5-dihydroimidazo- and imidazo[1,5-a]quinoxalines via modified Pictet–Spengler reaction

An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction.     

Understanding the Diels-Alder reactivity of 1,2-azaborine analogues

The Diels-Alder reactivity of 1,2-heteroborines (H₄C₄B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed.