流动注射化学发光抑制法测定吡罗昔康

基于吖啶橙在氢氧化钠介质中能被高锰酸钾氧化产生较强的化学发光,吡罗昔康能强烈抑制其化学发光,建立了高锰酸钾-吖啶橙-吡罗昔康化学发光抑制测定吡罗昔康的新方法。吡罗昔康在1.0×10-5~7.0×10-4g/mL范围内与化学发光强度呈良好线性关系,方法的检出限为4.5×10-6g/mL,对1.0×10-5g/mL吡罗昔康连续进行6次测定的相对标准偏差为3.6%。     

无机偶合流动注射化学发光测定钛的研究

基于钛(Ⅲ)对铬(Ⅵ)氧化I-产生I2的诱导作用,和I2氧化鲁米诺产生化学发光的反应,建立了无机偶合反应流动注射化学发光测定痕量钛的新方法。方法线性范围为1×10-9～1×10-5g/mL,RSD=3.0%(n=11,ρ=1×10-7g/mL),检出限为4.0×10-10g/mL。方法用于人发样品中钛的测定。     

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。     

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。     

顺序注射化学发光测定非那西汀

根据四价铈在酸性介质中氧化非那西汀产生化学发光，建立了顺序注射化学发光测定非那西汀的方法。该法线性范围为4．0×10－9～1．0×10－6g/mL，检出限为1．0×10－9g／mL，，对5．0×10-8g/mL非那西汀7次平行测定的相对标准偏差为1．2％。不需分离和其它预处理可直接用于药物生产的过程分析。     

反向流动注射化学发光法测定五氟利多

基于五氟利多对 KIO4- Luminol体系化学发光有强烈的增敏作用, 结合反向流动注射技术, 首次建立了测定五氟利多的流动注射化学发光的方法; 在优化的实验条件下, 测定五氟利多的线性范围为 4.0× 10- 8～ 1.0× 10- 5 g/mL, 检出限为 9.2× 10- 9 g/mL, 对 4.0× 10- 7 g/mL的五氟利多进行 11次平行测定, 方法的相对标准偏差为 2.1%; 该法用于片剂五氟利多的含量测定, 结果满意.     

时间分辨后化学发光同时测定林可霉素和卡那霉素

根据林可霉素、卡那霉素在过氧化单硫酸盐(PMS)-鲁米诺(Luminol)体系中的化学发光反应动力学性质的明显差异,建立了时间分辨后化学发光同时测定林可霉素和卡那霉素的新方法.在PMS-鲁米诺体系中林可霉素化学发光反应较快,0.8s达到最大值,峰尖锐;卡那霉素化学发光反应较慢,54.8s后达到最大值,峰平缓,且其动力学曲线呈现出随时间分开的两个独立的发光峰,互不干扰.该方法测定林可霉素、卡那霉素的线性范围分别为4.0×10-9～8.0×10-7 g/mL、4.0×10-7～8.0×10-5 g/mL,对8.0×10-8 g/mL的林可霉素溶液和8.0×10-6 g/mL的卡那霉素溶液进行测定,其相对标准偏差(RSD,n=11)分别为4.6％和3.3％,测定林可霉素和卡那霉素的检出限分别为1.0×10-9 g/mL和1.0×10-7 g/mL.     

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双嘧达莫

采用流动注射技术研究了酸性条件下,双嘧达莫与高锰酸钾和过氧化氢的化学发光行为,对影响化学发光强度的诸因素进行了实验和探讨,建立了流动注射化学发光法测定双嘧达莫的新方法。方法的检出限为5．8×10-8g／mL,线性范围为2×10-7～8×10-5g／mL,对4×10-6g/mL双嘧达莫进行了11次平行测定,相对标准偏差为1．4％。方法用于药剂中双嘧达莫含量的测定,结果与药典标准法测得值一致。     

流动注射化学发光法测定DL-酪氨酸

在甲醛存在下 ,高锰酸钾与DL 酪氨酸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DL 酪氨酸的化学发光分析法。方法的检出限为 2 .9× 1 0 - 8g/mL ,相对标准偏差为 1 .5 % ( 1 .0× 1 0 - 6g/mLDL 酪氨酸 ,n =1 1 ) ,线性范围为 1 .0× 1 0 - 7g/mL～ 5 .0× 1 0 - 6g/mL。     

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.