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高效液相色谱手性流动相添加剂分离西孟坦对映体 总被引:9,自引:0,他引:9
以 β 环糊精作为手性流动相添加剂 ,研究了DL 西孟坦在反相HPLC系统中的拆分。考察了缓冲盐的浓度、pH、β 环糊精的浓度、流动相中甲醇的比例、流动相流速和温度对手性分离的影响 ,建立了 β 环糊精动态手性固定相法分离西孟坦对映体的方法。色谱条件为 :ZirchromKromasilODS 1(5 μm ,15 0mm× 4 .6mm)色谱柱 ,流动相为 2 0mmol/L磷酸盐缓冲液 (pH 6 .0 )含 12mmol/Lβ 环糊精∶甲醇 (70∶30 ,V/V) ,流速为 0 .8mL/min ,温度为 17℃。DL 西孟坦对映体的保留时间分别为 2 2 .5和 2 4 .5min ,分离度为 1.5 7。 相似文献
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毛细管电泳法手性拆分合成药物氨氯地平及其中间体 总被引:6,自引:0,他引:6
建立了毛细管电泳手性拆分氨氯地平药物中间体的方法 ,并同时拆分了氨氯地平。考察了不同手性拆分试剂对手性选择性的影响 ,其中羧甲基 β 环糊精 (CM β CD)能够给出满意的拆分结果。在以CM β CD为手性拆分试剂的基础上 ,还考察了各种因素诸如流动相的pH值、环糊精的浓度以及电压对分离的影响。最佳拆分条件为 :30mmol/L磷酸盐 +5 0mmol/LCM β CD(pH 6 12 )。在此条件下 ,药物中间体及氨氯地平的分离度分别为 1 5 5和 1 73,结果令人满意。 相似文献
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报道了以未涂层融硅石英毛细管(50 cm×75 μm)为分离柱,5 mmol/L NaOH+10 mmol/L Citric acid +3 mmol/L H3BO3+10 mmol/L β-CD (pH 3.5) 为电泳介质,分离电压12 kV,检测电压0.80 V,建立了朴尔敏对映体拆分的高效毛细管电泳-方波安培检测方法.对缓冲溶液的种类、浓度、pH、分离电压对拆分效果的影响进行了讨论,并对拆分机理进行了探讨. 相似文献
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以手性冠醚为胶束毛细管电泳手性分离选择剂,对吉米沙星对映体药物的在线富集分离进行了研究.考察了阳离子表面活性剂十二烷基三甲基溴化铵浓度、运行缓冲溶液中有机添加剂含量和进样方式对对映体的富集和分离度的影响.使用未涂层毛细管柱(37 cm×51 μm,有效柱长30 cm),45 mmol/L Bis-Tris缓冲液+10 mmol/L十二烷基三甲基溴化铵(DTAB)+1 mmol/L手性冠醚+11%乙腈为运行缓冲溶液(pH=4.0),在紫外检测波长280 nm、运行电压-10 kV、电动进样条件下,对吉米沙星对映体进行在线推扫(sweeping)富集分离,在基线分离的前提下,富集倍数可达600~700倍.吉米沙星浓度为0.3 μmol/L时,两对映体峰高的相对标准偏差<4.0%(n=7).本方法为毛细管电泳在痕量对映体药物分析等方面的应用提供了新方法. 相似文献
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Uroš Grošelj Mojca Žorž Amalija Golobič Branko Stanovnik Jurij Svete 《Tetrahedron》2013,69(52):11092-11108
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. 相似文献
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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. 相似文献
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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%). 相似文献
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Shashikant U. Dighe Surya K. Samanta Shivalinga Kolle Sanjay Batra 《Tetrahedron》2017,73(17):2455-2467
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. 相似文献
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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. 相似文献
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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. 相似文献
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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. 相似文献
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Jona Mirnik Eva Pušavec Kirar Sebastijan Ričko Uroš Grošelj Amalija Golobič Franc Požgan Bogdan Štefane Jurij Svete 《Tetrahedron》2017,73(24):3329-3337
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 CuI 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). 相似文献
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George E. Magoulas Thomas Garnelis Constantinos M. Athanassopoulos Dionissios Papaioannou George Mattheolabakis Konstantinos Avgoustakis Dimitra Hadjipavlou-Litina 《Tetrahedron》2012,68(35):7041-7049
(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. 相似文献