阿替洛尔与醌茜素的荷移反应研究

研究了阿替洛尔与醌茜素之间的荷移反应。阿替洛尔作为电子给体,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,表观摩尔吸光系数为7.91×103L.mol-1.cm-1,阿替洛尔药物质量浓度在0～30mg/L范围内服从比耳定律,相对标准偏差为0.92%(n=6)。应用本法测定了片剂中阿替洛尔的含量,回收率为98.9%～101.6%。     

奋乃静与甲酚红的荷移反应研究

采用光度法研究了电子给予体奋乃静与电子接受体甲酚红之间的荷移反应,据此建立了荷移光度法测定奋乃静含量的方法.实验表明,奋乃静与甲酚红在丙酮介质中,室温条件下即可形成稳定的1:2型荷移络合物,该络合物的最大吸收波长为434nm,表观摩尔吸光系数为1.19×10<'4>L·mol<'-1>·cm<'-1>.奋乃静的质量浓度...     

荷移分光光度法测定头孢拉定

采用紫外可见分光光度法研究了头孢拉定与茜素之间的荷移反应,从而建立了一种快速简便测定头孢拉定的荷移分光光度法。实验表明,在乙醇-水介质中,头孢拉定与茜素在30℃水浴中反应45 min后形成稳定的1∶1型荷移络合物,该络合物的λmax=524 nm,表观摩尔吸光系数为2.01&#215;10^4L.mol^-1.cm^-1。头孢拉定药物质量浓度在0.87-87μg/mL范围内服从比尔定律,r=0.9990。相对标准偏差为1.1%（n=7）,加标回收率为91.4%-103.6%。     

少量水存在下桂利嗪和茜素在甲醇中的荷移反应

研究了在少量水存在下桂利嗪和茜素在甲醇介质中的电荷转移反应,确定了最佳反应条件。研究表明,反应生成1∶1型荷移络合物,该络合物的λmax=527nm,表观摩尔吸光系数ε=2.94×103L·mol-1·cm-1,桂利嗪浓度在25～200mg/L范围内符合比尔定律,相对标准偏差为1.55%(n=6),平均回收率在98%以上。     

奥硝唑与氯醌酸的荷移反应研究

研究了奥硝唑与氯醌酸在正丙醇介质的荷移反应,建立了一种快速简便测定奥硝唑的荷移分光光度法.在室温下,荷移反应生成2∶1的荷移络合物,最大吸收波长为534nm,表观摩尔吸光系数为ε=1.08×104 L·mol-1·cm-1.奥硝唑的浓度在5.0~83mg/L范围内服从比尔定律,相关系数r=0.999 3,相对标准偏差为1.3%~2.1%,回收率为99.1%~101.7%.     

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.     

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 %。     

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     

阿米卡星荷移反应及荧光光谱性质研究

研究了阿米卡星与电子受体氯醌酸之间的荷移反应。实验表明:在无水乙醇中,阿米卡星与氯醌酸在室温(25±5℃)下可迅速形成紫色的荷移络合物,此络合物常温下可稳定50 min,其荧光强度较阿米卡星显著增强,最大激发和发射波长分别红移135 nm和53 nm。阿米卡星含量在80~800μg/L范围内与其荧光强度呈良好的线性关系,相关系数r为0.9994,检出限为28.9μg/L。本法用于实际样品分析,回收率为95.5%~101.4%,相对标准偏差(RSD)为0.47%。     

胶束增稳荷移反应紫外分光光度法测定洛美沙星

提出了一种基于胶束增稳荷移反应测定洛美沙星的紫外分光光光度法 ,研究了在阳离子表面活性剂溴化十六烷基吡啶 (CPB)胶束体系中电子给体洛美沙星与电子受体四氯对苯醌之间的荷移反应产物的紫外光谱性质。发现CPB对洛美沙星与四氯对苯醌的荷移反应络合物有显著的增稳效应。洛美沙星的浓度在0 .8～ 5 4mg L范围内符合比尔定律 ,r =0 .9994。在测定波长 32 3nm处 ,络合物的表观摩尔吸光系数为 3.5 6×10 - 4L·mol- 1 ·cm- 1 。本方法用于片剂中洛美沙星含量的测定 ,其回收率为 97.8%～ 10 0 .5 % ,相对标准偏差为0 .9%～ 2 .4 %。     

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%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

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.     

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.     

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.     

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.     

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.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.