扑尔敏与铬天青S荷移反应分光光度法测定扑尔敏的含量

研究了扑尔敏与铬天青S的电荷转移反应,确定了反应条件,建立了测定扑尔敏的分光光度法。扑尔敏与铬天青S在水溶液中发生电荷转移反应,常温下反应20min后可比色。电荷转移络合物的最大吸收波长是532nm,表观摩尔吸光系数为2.27×103L·mol-1·cm-1。扑尔敏质量浓度在20～160mg·L-1范围内服从比耳定律,相关系数为0.9990。当扑尔敏浓度为80mg·L-1时,六次测定结果的相对标准偏差为1.39%。测得荷移络合物的组成为1∶1、稳定常熟为1.48×105,探讨了反应机理。本方法用于测定片剂中扑尔敏的含量,结果与文献方法一致,回收率在99.0%以上。     

富马酸比索洛尔与茜素的荷移反应研究

研究了富马酸比索洛尔与茜素的电荷转移反应条件,建立了快速测定富马酸比索洛尔的可见分光光度法。富马酸比索洛尔与茜素反应生成的电荷转移络合物的最大吸收波长是542nm,表观摩尔吸光系数为4.67×103L·mol-1·cm-1。富马酸比索洛尔质量浓度在12～160mg·L-1范围内服从比耳定律,相关系数为0.9993。当富马酸比索洛尔浓度为80mg·L-1时,六次测定结果的相对标准偏差为1.42%。测得荷移络合物的组成比和稳定常数分别为1∶1和1.53×104。本方法用于测定胶囊中富马酸比索洛尔的含量结果与文献方法相符,平均回收率在99.0%以上。     

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%。     

铁(Ⅲ)-铬天青S-盐酸氯丙嗪三元配合物分光光度法测定微量铁

根据铬天青S(CAS)、盐酸氯丙嗪(CPH)与铁(Ⅲ)的显色反应,采用铁(Ⅲ)-铬天青S-氯丙嗪三元配合物分光光度法测定微量铁的含量。在pH 5.50的乙酸-乙酸钠缓冲溶液中,铁(Ⅲ)-CAS-CPH生成1比2比2的蓝色三元配合物,其最大吸收波长为660nm,表观摩尔吸光系数为4.77×104L·mol-1·cm-1。铁(Ⅲ)的质量浓度在0.02~1.2mg·L-1范围内与其吸光度呈线性关系,方法的检出限(3s/k)为7.6×10-3 mg·L-1。加标回收率在98.4%~99.5%之间,测定值的相对标准偏差(n=5)在1.8%~2.3%之间。     

特非那定的荷移分光光度法测定

研究了特非那定与甲基红的电荷转移反应,建立了快速测定特非那定的可见分光光度法.结果表明,电荷转移络合物的络合比为1∶1,最大吸收波长是430nm,表观摩尔吸光系数为1.15×104 L·mol-1·cm-1.特非那定质量浓度在0.4~48mg/L范围内服从比耳定律,相关系数为0.998 9.当特非那定浓度为20mg/L时,6次测定结果的相对标准偏差为1.40%.本方法用于测定药物中特非那定的含量,加标回收率为97.8%和101.2%.     

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.     

硝普钠分光光度法测定对乙酰氨基酚

建立了硝普钠分光光度法测定对乙酰氨基酚的方法。研究表明:在碱性条件下,对乙酰氨基酚与硝普钠以1∶2的化学计量比反应形成一种绿色产物,其最大吸收波长为698nm。对乙酰氨基酚在1.7～102μg·mL-1浓度范围内与吸光度成良好线性关系,线性回归方程为A=0.02804+0.02285c(μg·mL-1),线性相关系数r=0.9986,表观摩尔吸收系数ε698=3.5×103L·mol-1·cm-1,检测限(3s·k-1)为1.42μg·mL-1。本方法成功应用于药物样品中对乙酰氨基酚含量的测定,回收率在97.6%～102.0%,结果满意。     

铬天青S–盐酸氯丙嗪–溴化十六烷基三甲铵光度法测定水样中的铁

采用铁(Ⅲ)–铬天青S–盐酸氯丙嗪–溴化十六烷基三甲铵(CTMAB)四元配合物光度法测定水样中铁的含量。在pH 5.50的HAc–NaAc缓冲介质中,在铁(Ⅲ)–铬天青S–盐酸氯丙嗪显色反应中,加入CTMAB,四元配合物的表观摩尔吸光系数为9.85×10~4 L/(mol·cm),是三元配合物灵敏度的两倍。结果表明,配合物在657nm波长处有最大吸收,Fe(Ⅲ)的质量浓度在0~20μg/(25 mL)范围内与吸光度呈良好的线性关系,线性相关系数为0.999 6,方法的检出限为1.84×10~(–3) mg/L。样品加标回收率为97.3%~98.8%,测定结果的相对标准偏差为1.9%~3.2%(n=5)。该方法灵敏度高,精密度与准确度好,便于在实验室推广应用。     

衍生化-离子液体萃取分光光度法测定盐酸美西律

盐酸美西律与1,2-萘醌-4-磺酸钠在pH=9.0的介质中反应生成一种橙红色衍生物,该衍生物能被离子液体所萃取,其最大吸收波长发生较大幅度红移,吸光度显著增强。据此建立了高选择性的测定盐酸美西律的衍生化-离子液体萃取分光光度法。萃取后的衍生物在448 nm处的表观摩尔吸光系数ε为2.69×104L·mol-1·cm-1。盐酸美西律浓度在0.2～5.4μg·mL-1范围内符合比耳定律,相关系数为0.9994,检出限为0.067μg·mL-1。该方法已用于药物制剂及尿样中盐酸美西律的测定,其回收率分别为99.5%～100.7%和96.6%～101.5%。     

分光光度法测定红霉素——基于与甲基紫的荷移反应

考察了红霉素与甲基紫电荷转移反应的条件.试验结果表明:以水为溶剂,红霉素与甲基紫在50℃水浴中进行电荷转移反应生成1:1稳定的配合物,其最大吸收波长为583 nm.摩尔吸光率为1.61×104L·mol-1·cm-1,对红霉素标准进行9次测定,相对标准偏差为0.91%.红霉素的质量浓度在2.1 mg/25 mL以内服从比耳定律,方法的检出限(S/N=3)为1.51 mg·L-1,回收率大于97.5%,方法可用于红霉素肠溶片和兽用红霉素测定.     

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.     

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).     

Synthesis and antioxidative/anti-inflammatory activity of novel fullerene–polyamine conjugates

(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C₆₀, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine.