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 共查询到20条相似文献,搜索用时 62 毫秒
1.
多功能基和氮杂冠醚键合固定相的制备与鉴定   总被引:1,自引:1,他引:0  
达世禄  张元伟  董亚琼  王忠华  范畴 《色谱》1995,13(3):161-165
在全多孔微粒硅胶表面进行连续固-液相反应,制备氯丙基(CPS)、乙二醇氨丙基(DEAP)、3-[氮杂18-冠-6]-丙基(BCP)键合固定相。采用有机元素分析、功能基分析、热分析、红外光谱和金属离子络合容量测定等对键合相进行鉴定和表征。化学和仪器分析结果表明,键合反应按预定路线进行。键合固定相具有各种色谱性能,其极性效应对分离选择性起重要作用。  相似文献   

2.
C_(60)键合硅胶液相色谱固定相的合成及其性能评价   总被引:2,自引:0,他引:2  
以γ-(乙二胺基)丙基三乙氧基硅烷为偶联剂合成了C60键合硅胶固定相;用元素分析法测定得到该固定相的C60键合量为57.57μmol/g。考察了多环芳烃和杯芳烃在C60键合硅胶固定相上的分离,多环芳烃在该固定相上的洗脱顺序与ODS固定相相似;杯芳烃的洗脱顺序为杯[8]、杯[4]和杯[6]芳烃。  相似文献   

3.
C_(60)键合硅胶液相色谱固定相的合成及其性能评价   总被引:3,自引:1,他引:3  
刘英  达世禄  陈远荫 《色谱》1998,16(2):115-117
 以γ-(乙二胺基)丙基三乙氧基硅烷为偶联剂合成了C60键合硅胶固定相;用元素分析法测定得到该固定相的C60键合量为57.57μmol/g。考察了多环芳烃和杯芳烃在C60键合硅胶固定相上的分离,多环芳烃在该固定相上的洗脱顺序与ODS固定相相似;杯芳烃的洗脱顺序为杯[8]、杯[4]和杯[6]芳烃。  相似文献   

4.
β—环糊精键合固定相合成方法和色谱性能研究   总被引:6,自引:0,他引:6  
以两种不同的路线合成β-环瑚精-环氧丙氧丙基键合硅胶固定相(β_CD-GPS)。比较了两种方法得到的键合相的键合量。采用非水滴定法考察了影响键合反应的因素。选择了合成β_CD-GPS最佳反应条件,并对其色谱性能进行了考察。  相似文献   

5.
用新合成的3-(二乙醇)氨丙基硅氧烷(DEAP)、3-(氮杂18-冠-6)丙基硅氧烷(BCP)作固定相,对二取代苯异构物进行液相色谱分离,研究流动相组成,pH值及其K ̄+离子浓度对色谱行为的影响.探讨溶质保留机理,并比较DEAP、BCP与ODS的色谱性能.  相似文献   

6.
β-环糊精键合硅胶经对甲苯磺酰化后, 与8-羟基喹啉反应得到8-羟基喹啉衍生化β-环糊精键合硅胶固定相(QCDS). 采用元素分析、热分析及固体核磁波谱对键合固定相进行表征. 考察了QCDS对位置异构体、丹磺酰化氨基酸异构体、苯丙酸类药物和核苷等的分离性能.  相似文献   

7.
报道在硅胶表面进行固-液相反庆合成的3-(氮杂-18-冠-6)丙基键合固定相对金属离子的络合能力和色谱性能,研究了流动相组成、PH值、金属离子对极性二取代苯保留值的影响。探讨色谱分离机理。这种键合相通过对金属离子的络合,显示多种多谱分离机理,对极性二取代苯异构体分离选择性、分析速度均优于对比的C18健合固定相反相色谱。  相似文献   

8.
r-氯丙基、二乙醇氨丙基键合硅胶固定相分析甾体激素药物的高效液相色谱研究齐广才(延安大学化学系延安716000)达世禄,张元伟,王忠华(武汉大学化学系武汉430072)关键词极性键合固定相,甾体激素,高效液相色谱甾体激素及其衍生物是一类重要临床药物,...  相似文献   

9.
将三(苯基氨基甲酸)支链淀粉酯涂敷在硅胶上制成了手性固定相.将支链淀粉与过量的苯异氰酸酯在吡啶中反应得到的苯基氨基甲酸酯溶解并涂敷在用3-氨基丙基三乙氧基硅烷处理过的硅胶上,涂敷量为0.45/2.55(重量比).用此手性固定相拆分了外消旋的簇合物μ-FcCCHCoW(CO)5(CpCOOC2H5).拆分在室温下进行,洗脱液为甲醇,流速为0.5mL/min.  相似文献   

10.
将三(苯基氨基甲酸)支链淀粉酯涂敷在硅胶上制成了手性固定相,将支链淀粉与过量的苯异氰酸酯在吡啶中反应得到的苯基氨基甲酸酯溶液并涂敷在用3-氨基丙基三乙氧基硅烷处理过的硅胶上,涂敷量为0.45/2.55重量比,用此手性固定相拆分子外消旋的簇合物μ-FcC=CHCoW(CO)5(CpCOOC2H5),拆分在室温下进行,洗脱液为甲醇,流速为0.5mL/min。  相似文献   

11.
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%.  相似文献   

12.
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.  相似文献   

13.
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.  相似文献   

14.
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.  相似文献   

15.
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.  相似文献   

16.
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.  相似文献   

17.
Zhanhui Yang  Shiyi Yang  Jiaxi Xu 《Tetrahedron》2017,73(23):3240-3248
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.  相似文献   

18.
19.
《Tetrahedron》2014,70(21):3377-3384
The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.  相似文献   

20.
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.  相似文献   

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