共查询到20条相似文献,搜索用时 46 毫秒
1.
2.
3.
采用多糖类手性色谱柱,建立了(2-戊基-3-苯基-2,3环氧丙烷基)二苯基磷酸酯对映体的高效液相色谱手性拆分方法。考察了手性柱类型、流动相组成、流速、柱温等对手性拆分的影响,并对分离机制进行了探讨。结果表明,采用Chiralpak AS-H柱(250×4.6mm,i.d.,5μm),以正己烷-异丙醇(85∶15,V/V)为流动相,在柱温25℃,流速1.0mL/min,检测波长210nm的条件下,(2-戊基-3-苯基-2,3环氧丙烷基)二苯基磷酸酯对映体能达到完全分离,且稳定性和重复性好。该方法也适用于(2-戊基-3-苯基-2,3环氧丙烷基)二苯基磷酸酯类似物的手性拆分。 相似文献
4.
5.
采用多糖类手性固定相,建立2-戊基-3-苯基-2,3-环氧丙醇对映体的高效液相色谱(HPLC)手性分析方法。考察了手性柱类型、流动相组成、流速及柱温对2-戊基-3-苯基-2,3-环氧丙醇对映体拆分的影响。结果表明,以Chiralcel OD-H色谱柱(25×0.46cm,5μm)分离,采用正己烷-异丙醇(V/V,90∶10)作流动相,在流速为0.8 mL·min-1,柱温25℃,检测波长210nm的条件下,2-戊基-3-苯基-2,3-环氧丙醇对映体能达到基线分离,且具有较好的重复性和稳定性,可用于对映体的拆分及质量控制。该方法也适用于2-戊基-3-苯基-2,3-环氧丙醇类似物质的手性拆分。 相似文献
6.
手性流动相添加剂法对两种手性化合物的直接拆分 总被引:3,自引:0,他引:3
以β-环糊精为手性流动相添加剂,于C8反相柱上建立了2种手性农药(包括杀菌剂己唑醇和杀虫剂SR-生物丙烯菊酯)对映体的高效液相色谱拆分方法。探讨了β-环糊精浓度、流动相pH、有机改性剂种类等因素对手性拆分的影响。结果表明:在流动相为β-环糊精水溶液、磷酸钠缓冲液(0.05mol/L)、乙腈、三乙胺(体积比50:30:20:0.5)条件下,己唑醇对映体在pH为7.4,β-环糊精溶液浓度为7mmol/L时,SR-生物丙烯菊酯对映体在pH为6.4,β-环糊精浓度为10.5mmol/L时得到最佳分离。 相似文献
7.
表层二氧化锆/硅基-CDMPC手性固定相的制备及联苯双酯类保肝药的直接拆分 总被引:1,自引:0,他引:1
用分子自组装的方法制备了表层纳米氧化锆包覆多孔微米硅球,得到的氧化锆 /硅胶微球用作高效液相色谱担体,本方法制备的担体具有氧化锆的表面特性并保 持了硅胶的颗粒均匀、表面积大、渗透性好的优点,可以制备大涂敷量的手性固定 相,以增加固定相的手性识别能力,以涂敷量为20%的纤维素-三(3,5-二甲基苯 基氨基甲酸酯)-氧化锆/硅胶手性固定相(CDMPC-coated ZrO_2/SiO_2)上,对 联苯双酯类保肝药物进行直接拆分,考察了流动相极性、第二种极性改性剂对样品 保留和拆分的影响;并对手性拆分机理进行了阐述,结果表明:CDMPC- ZrO_2/SiO_2手性固定相比CDMPC-ZrO_2具有更好的手性拆分能力。 相似文献
8.
以微晶纤维素和3,5-二甲基苯基氨基甲酸酯为原料,合成了纤维素-三(3,5-二甲基苯基氨基甲酸酯)(CDMPC),将其分别涂敷于小孔硅胶(SG)、氨丙基化小孔硅胶(APS-SG)和介孔SBA-15微球上,制得3种手性固定相:SG@CDMPC(CSP1)、APS-SG@CDMPC(CSP2)及SBA-15@CDMPC(CSP3),正相条件下考察了12种中性或酸性手性化合物在自制手性固定相上的拆分效果,并与商品柱Chiralcel OD-H的拆分性能进行了对比。 6个手性化合物在CSP1上获得比在商品柱上更高的柱效,其中2个手性化合物获得比在商品柱上更高的分离因子和分离度,而CSP2和CSP3的拆分效果总体较CSP1和商品柱的差。 探讨了自制手性固定相对华法令的拆分和定量测定,华法令在CSP1上的检测限为10 μg/L,在0.05~5 g/L范围内线性关系良好。 相似文献
9.
建立了手性柱HPLC法测定盐酸贝那普利的中间体(R)-α-羟基苯丁酸乙酯中的(S)-α-羟基苯丁酸乙酯。采用Chiralcel OD-H色谱柱,流动相正己烷-异丙醇(体积比90:10),流速1.0mL/min,检测波长254nm,进样体积20μL,按外标法以峰面积计算(R)-α-羟基苯丁酸乙酯中的(S)-α-羟基苯丁酸乙酯的含量。(S)体的线性范围5.5~23.8μg/mL,检出限0.47μg/mL(S/N=3),回收率为96%~103%,精密度RSD为2.1%(n=6)。 相似文献
10.
在水-环己烷微乳体系中制备高比表面积氧化锆 总被引:5,自引:0,他引:5
在水/TritonX-100/环己烷/正己醇微乳体系中合成了氧化锆粉末,经过450℃氧气中焙烧和400℃抽真空处理后,获得了比表面积高达464m2/g的氧化锆粉末.X射线衍射测试表明,该化合物最初为无定形氧化锆,经450℃焙烧3h后开始出现四方晶相和少量的单斜晶相氧化锆,随着焙烧温度升高至900℃,单斜晶相增加,但四方晶相仍是主要的.在600℃以下,添加氧化锰会阻止单斜晶相氧化锆的出现,使所制备的15%MnO2-ZrO2具有较高的可逆吸附氮氧化物的能力. 相似文献
11.
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
12.
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
13.
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
14.
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
15.
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
16.
An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions. 相似文献
17.
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
18.
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
19.
20.
An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction. 相似文献