高锰酸钾-甲醛-阿莫西林体系化学发光的研究及应用

在酸性介质中,高锰酸钾能氧化阿莫西林发生化学发光反应,而甲醛的存在可使发光强度增强。据此,采用流动注射技术,建立了一种测定阿莫西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1.52%(n=11,c=1.0×10-5g/mL),线性范围为5.0×10-8~2.0×10-5g/mL。该法已用于阿莫西林胶囊中阿莫西林含量的测定,结果满意。     

KMnO4-甲醛-茚三酮化学发光体系的研究

在甲醛存在下,KMnO4与茚三酮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KMnO4-甲醛-茚三酮化学发光体系测定茚三酮的方法.方法的检出限为3×10-8 g/mL;相对标准偏差为1.1%(4.0×10-6g/mL茚三酮,n=11);线性范围为1.0×10-7～2.0×10-4 g/mL.本法已用于样品中茚三酮的测定.     

K3Fe(CN)6-钙黄绿素体系后化学发光反应测定盐酸氯丙嗪

发现了盐酸氯丙嗪在K3Fe(CN)6-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盐酸氯丙嗪的流动注射化学发光分析法.方法的检出限为3×10-8/mL,相对标准偏差为2.0%(2.0×10-6 g/mL盐酸氯丙嗪,n=11),线性范围为1.0×10-7～1.0×10-5 g/mL.此法已用于盐酸氯丙嗪片剂中盐酸氯丙嗪含量的测定,结果与药典方法测定值一致.     

毛细管电泳-化学发光法测定人血清中的异烟肼

基于碱性介质中异烟肼对laminol-K3Fe(CN)6化学发光体系的增敏作用,设计了一个经毛细管电泳(CE)分离,在线化学发光检测异烟肼的新方法.研究并优化了毛细管电泳分离及化学发光检测的条件.在优化的实验条件下,该方法测定异烟肼的线性范围为4.0×10-7～1.0×10-5g/mL(R2=0.9984),检出限(3σ)为1×10-8g/mL,对6.0×10-6g/mL的异烟肼进行6次平行测定,其相对标准偏差为4.0%.方法已用于血清中异烟肼的测定.     

纳米金催化鲁米诺化学发光体系测定甲巯咪唑

在碱性介质中,甲巯咪唑能强烈增敏纳米金-鲁米诺-硝酸银化学发光体系产生较强的化学发光信号,据此建立了一种流动注射化学发光测定甲巯咪唑的新方法。在优化实验条件下,该方法对甲巯咪唑的检测线性范围为1.0×10-9~1.0×10-8、1.0×10-8~1.0×10-7、1.0×10-7~1.0×10-6g/mL,检出限(S/N=3)为3.0×10-10g/mL,相对标准偏差为1.2%(n=11,ρ=1.0×10-8g/mL)。将该法用于药物中甲巯咪唑含量的测定,结果满意。同时,采用化学发光光谱表征技术对该体系的化学发光反应机理进行了初步探讨。     

铁氰化钾-钙黄绿素体系后化学发光反应测定盐酸硫利达嗪

报道了盐酸硫利达嗪在铁氰化钾-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,并建立了一种利用后化学发光反应测定盐酸硫利达嗪的流动注射化学发光分析法。方法的检出限为2.0×10-7g/mL,对2.0×10-6g/mL盐酸硫利达嗪测定的相对标准偏差为2.0%(n=11),线性范围为5.0×10-7～5.0×10-5g/mL。该法已用于盐酸硫利达嗪片剂中盐酸硫利达嗪含量的测定,结果与药典方法测定值一致。     

鲁米诺-铁氰化钾化学发光体系测定左旋多巴

铁氰化钾在碱性条件能氧化鲁米诺而发光,左旋多巴能大大增强该发光强度。基于此现象并结合流动注射技术,建立起一种直接测定左旋多巴的流动注射化学发光分析法。方法检出限为1.2×10-10g mL,左旋多巴质量浓度在5 0×10-10～5.0×10-8g mL范围内与发光强度呈良好的线性关系。相对标准偏差为2.9%(左旋多巴5.0×10-9g mL,n=11)。该方法可用于片剂中左旋多巴量的测定。     

KMnO_4-甲醛流动注射化学发光法测定木犀草素

在酸性介质中,木犀草素在KMnO4-HCHO体系中产生化学发光,据此建立了一种简便、快速测定木犀草素的化学发光新方法。化学发光强度与木犀草素的浓度在5.0×10-8~1.5×10-5g/mL范围内呈现出良好的线性关系。其检测限(3σ)为3.0×10-8g/mL,对8.0×10-7g/mL的木犀草素溶液进行11次平行测定,相对标准偏差为2.8%。方法可应用于实际样品和合成样品中木犀草素的测定。并探讨了反应的机理。     

铁氰化钾-鲁米诺体系后化学发光行为的研究-流动注射后化学发光法测定可待因

发现了可待因在铁氰化钾鲁米诺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可待因的流动注射化学发光新方法。方法的检出限为3×10-8g mL,相对标准偏差为1.9%(1.0×10-6g mL可待因,n=11),线性范围为8.0×10-8～1.0×10-5g mL。此法已用于可待因片剂中可待因的测定,结果与药典方法测定值一致。     

硫酸卡那霉素化学发光新方法的研究

在碱性溶液中,N-溴代丁二酰亚胺可以氧化曙红产生化学发光,硫酸卡那霉素的存在可以显著地增强这一反应的化学发光信号。基于此发现,优化了实验条件,建立了测定硫酸卡那霉素的流动注射化学发光新方法。方法测定硫酸卡那霉素的线性范围为1.0×10-7～2.0×10-5g/mL,检出限为6×10-8g/mL,相对标准偏差为1.3%(5.0×10-6g/mL硫酸卡那霉素溶液,n=11)。该方法已用于滴眼液中硫酸卡那霉素含量的测定。对化学发光反应的机理也进行了初步的探讨。     

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.