醌茜素显色分光光度法测定奋乃静

研究了奋乃静(Perphenazine,PPH)与醌茜素(Quinalizarin,QLZ)之间的荷移光谱及其性能。奋乃静作为电子给体,醌茜素作为电子受体,两者在乙醇-水介质中反应生成荷移络合物。该络合物的λmax=568nm,表观摩尔吸光系数是3.39×103 L.mol-1.cm-1,奋乃静药物质量浓度在0～35mg/L范围内服从比耳定律,相对标准偏差为1.23%(n=6),回收率为98.9%～102.4%。     

基于氯冉酸的荷移反应分光光度法测定奋乃静

奋乃静(PPH)是吩噻嗪类抗精神病药,用于治疗精神分裂症及其他精神躁狂症,也可用于呕吐及严重焦虑的治疗。目前,测定奋乃静的方法有紫外分光光度法、高效液相色谱法、电化学法、毛细管电泳法、流动注射分析法、荧光光谱法、二阶导数光谱法和极谱法等。采用氯冉酸荷移分光光度法测定奋乃静尚未见文献报道,本工作利用奋乃静与氯冉酸的荷移反应,建立了荷移分光光     

基于与茜素红的荷移反应光度法测定苯妥英钠

采用光度法研究了电子给予体苯妥英钠与电子接受体茜素红之间的荷移反应,据此建立了荷移光度法测定苯妥英钠含量的方法.在水溶液中,苯妥英钠与茜素红荷移络合物的最大吸收波长为530 nm,该络合物的组成为1:1,表观摩尔吸光率为6.54×103L·mol-1·cm-1,稳定常数为2.26×105.苯妥英钠的质量浓度在4～40 mg·L-1叫范围内符合比耳定律.当苯妥英钠质量浓度为20 mg·L-1时,相对标准偏差(n=10)为1.23%.测定了片剂中苯妥英钠的含量,加标回收率在97.7%～101.0%之间.     

荷移光度法测定依诺沙星

依诺沙星与茜素红在水-乙醇介质中发生电荷转移反应,其中依诺沙星是电子给予体,茜素红是电子接受体,依据此荷移反应建立了一种快速测定依诺沙星的荷移分光光度法.荷移络合物在 546 nm 波长处有最大吸收,表观摩尔吸光率为 8.04×103L·mol-1·cm-1,相关系数为0.999 9.该络合物的组成为 1:1,表观稳定常数为 2.84×104.依诺沙星的质量浓度在 0～40 mg·L-1范围内服从比耳定律.当依诺沙星的质量浓度为 20 mg·L-1时,测定结果的相对标准偏差(n=6)为 1.2%,回收率在 99%以上.测定了依诺沙星制剂中有效成分的含量,与文献[1]方法结果基本吻合.     

阿替洛尔与紫色素的荷移反应研究

采用光度法研究了电子给予体阿替洛尔与电子接受体紫色素之间的荷移反应,据此建立了荷移光度法测定阿替洛尔含量的方法。实验表明,阿替洛尔与紫色素在乙醇介质中,室温条件下即可形成稳定的1∶1型荷移络合物,该络合物的最大吸收波长为542nm,表观摩尔吸光系数为6.17×103L.mo-l1.cm-1。阿替洛尔的质量浓度在0~35 mg.L-1范围内符合比尔定律,相关系数为0.9993。当阿替洛尔的质量浓度为20 mg.L-1时,测定结果的相对标准偏差(n=6)为0.78%。采用本法测定片剂中阿替洛尔的含量,平均回收率在98.9%~101.6%之间。     

荷移反应分光光度法测定苯巴比妥钠

采用分光光度法研究了电子给体苯巴比妥钠与π电子受体茜素红的荷移反应,建立了荷移分光光度法测定苯巴比妥钠的方法。在水溶液中,苯巴比妥钠与茜素红荷移络合物的最大吸收波长为530 nm,该络合物的组成为1∶1,表观摩尔吸光系数ε为4.43×103L.mol-1.cm-1,稳定常数为2.30×105。药物质量浓度在5~40 mg/L范围内符合比尔定律,相关系数为0.9996。当苯巴比妥钠浓度为20 mg/L时,10次测定结果的相对标准偏差为1.3%。测定了针剂中的苯巴比妥钠,加标回收率在98.9%~105%之间。     

司帕沙星与茜素红荷移反应的研究

采用紫外分光光度法研究了π电子受体茜素红与电子给予体司帕沙星的荷移反应。确定了反应条件,建立了一种快速简便灵敏准确测定司帕沙星的荷移分光光度法。结果表明,司帕沙星与茜素红在(4+6)乙醇-水介质中,室温条件下即可形成1∶1稳定的荷移络合物,该络合物的最大吸收波长为530 nm,表观摩尔吸光系数为4.8×103L.mol-1.cm-1,司帕沙星药物质量浓度在6~160mg/L范围内服从比尔定律,r=0.9991。当该法用于片剂中司帕沙星的测定时,回收率为99.75%~100.00%,相对标准偏差为1.4%(n=10)。     

艾司唑仑荷移反应及分析应用

采用紫外分光光度法研究了π电子受体四氯对苯醌 (TCBQ)与电子给予体艾司唑仑的荷移反应 ,结果表明 ,TCBQ与艾司唑仑在pH 8.2的BR缓冲溶液中能形成稳定的荷移反应络合物 ,吸光度显著增强。据此建立了测定艾司唑仑的简单、快速、准确和灵敏的方法。艾司唑仑浓度在 0 .2～ 3 .2mg/L范围内符合比尔定律。r=0 .9992。荷移络合物在 3 1 6nm处的表观摩尔吸光系数为 8.5× 1 0 4L·mol-1·cm-1。方法用于片剂中艾司唑仑含量的测定 ,其回收率为 99.2 %～ 99.7% ;相对标准偏差为 0 .7%～2 .1 %。     

琥乙红霉素与甲基红的荷移反应研究

研究了电子给体琥乙红霉素与电子受体甲基红之间的电荷转移反应,确定了反应的最佳条件,建立了一种快速、简便测定琥乙红霉素的荷移分光光度法。结果表明:琥乙红霉素与甲基红在乙醇-水介质中即可生成稳定的1∶1络合物,该络合物的最大吸收波长为421nm,表观摩尔吸光系数和稳定常数分别为1.48×104 L·mol-1·cm-1和1.445×105。琥乙红霉素浓度在2.0~84.0μg/mL范围内符合比耳定律,线性相关系数为0.9991,检出限为1.06μg/mL。该方法用于测定药物制剂中琥乙红霉素的含量,加标回收率为98.2%~101.6%。     

胶束增敏荷移分光光度法测定水中苯胺

用分光光度法研究了苯胺作为电子给体与电子受体茜素红的荷移反应。在pH 5.0乙酸介质中,苯胺与茜素红可形成1∶1的稳定荷移络合物,加入适量的十二烷基硫酸钠,可引起该络合物的吸光度显著增加,最大吸收波长为525 nm,表观摩尔吸光率为3.25×103L.mol-1.cm-1,苯胺的质量浓度在2.0～56.0 mg.L-1范围内呈线性关系。应用此法测定废水样中微量苯胺,并以此水样为基体作回收试验,测得平均回收率在100.3%。     

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%.     

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.     

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.     

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.     

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.     

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.     

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.     

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.