993 resultados para ~1H


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A facile and efficient one-pot synthesis of halogenated pyridin-2(1H)-ones from a series of readily available enaminones under Vilsmeier conditions is described, and a mechanism involving sequential halogenation, formylation, and intramolecular nucleophilic cyclization is proposed.

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基于核磁共振技术的代谢组学是近年发展起来的一种新的组学技术,主要利用生物体液的核磁共振谱提供生物体内全部小分子代谢物的丰富信息。然而,噪声的存在影响了模式识别方法分析的准确度。近年来小波变换以其多分辨率分析的特性、方法简单、快速等优点成为一种有效的去除分析信号噪声的方法。本实验通过运用小波变换去除噪声、校正基线后,再进行Fisher判别分析,得到了较传统分析更为清晰的代谢标识物,建立了良好的代谢模型

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An efficient and divergent one-pot synthesis of substituted 2H-pyrans, 4H-pyrans and pyridin-2(1H)-ones from beta-oxo amides based on the selection of the reaction conditions is reported. Mediated by N,N,N',N'-tetramethylchloroformamidinium chloride, beta-oxo amides underwent intermolecular cyclizations in the presence of triethylamine at room temperature to give substituted 2H-pyrans in high yields, which could be converted into substituted 4H-pyrans in the presence of sodium hydroxide in ethanol at room temperature, or into substituted pyridin-2(1H)-ones under reflux.

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A facile and efficient synthesis Of Substituted pyridin-2(1H)-ones has been developed by the reaction of readily available 1-carbamoyl-]-[3-(dimethylamino)propenoyl]cyclopropanes with phosphoryl chloride or phosphorus tribromide in dichloromethane at room temperature.

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In the title complex, [Cd(C2H3O2)(2)(C17H10N4O)(2)], the central Cd-II ion (site symmetry 2) shows an uncommon eight-coordinate CdN4O4 coordination geometry arising from two N,N-chelating 2-(2-furyl)-1H-imidazo[4,5-f]-1,10-phenanthro-line molecules and two O, O-bidentate acetate anions.

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A facile and efficient one-pot synthesis of highly substituted pyridin-2(1H)-ones is developed via the Vilsmeier-Haack reaction of readily available 1-acetyl,1-carbamoyl cyclopropanes, and a mechanism involving sequential ring-opening, haloformylation, and intramolecular nucleophilic cyclization reactions is proposed.

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A facile and efficient one-pot synthesis of highly substituted pyridin-2(IH)-ones was developed via Vilsmeier-Haack reactions of readily available enaminones, 2-arylamino-3-acetyl-5,6-dihydro-4H-pyrans, and a mechanism involving sequential ring-opening, haloformylation, and intramolecular nucleophilic cyclization reactions is proposed.

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In the asymmetric unit of the title compound, C9H8N2O2, there are two crystallographically independent molecules, each of which forms a dimer, via N-H center dot center dot center dot O hydrogen bonds, with an inversion-related molecule.

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In the title compound, [Zn(C8H4O4)(C17H10N4O)](n), the Zn-II atom is five-coordinated by two N atoms from the phenanthro-line-derived ligand and three O atoms from one bidentate and one monodentate benzene-1,2-dicarboxylate (1,2-BDC) dianions in a distorted trigonal-bipyramidal geometry. The Zn-II atoms are bridged by the 1,2-BDC ligands to form a single-chain structure. Neighboring chains interact through pi-pi interactions, leading to a two-dimensional network.

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对环化丁苯橡胶的1 H 核磁共振谱进行了归属分析 ,并推导出计算环化度和溶剂参与量的公式。设环化丁苯橡胶的1 H 核磁共振谱图中化学位移为 7 0 ,5 4,4 9和 3 0~ 0处的峰强度分别为A ,B ,C和D ,则环化丁苯橡胶中丁二烯总物质的量 (X) =(B +C +D - 2A) /7 1 ,未环化的丁二烯物质的量 (Y) =B/2 +C/4,参与反应的二甲苯物质的量 (Z) =( 1 7 5A -B -C -D) /46 5,环化度 (P) =1 -Y/X ,溶剂参与量 (W ) =91 6Z/X。

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采用激光解吸电离飞行时间质谱 (LDI TOF MS)快速测定了 1H 2 ,3 二氢 1 吡咯里嗪酮衍生物相对分子质量 ,初步总结了该类化合物的质谱规律 .实验中不需加入基质 ,实测值与理论计算值相吻合.

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对环化氯丁橡胶的1H -NMR谱进行了归属 ,并推导出计算环化氯丁橡胶 (CR)的环化度和溶剂参与量的公式。

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2DNMR谱的自动归属是核磁共振发展的一个方向,CAPRI即是蛋白质1H谱的计算机辅助谱峰归属的一种程序。作者将其应用于眼镜王蛇神经毒素CM-111H谱的归属,讨论了CAPRI的功能和特点以及运用在CM-11后得到的分析结果。

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随着稀土应用的日益扩大,稀土将有可能越来越多地进入生态环境和生物体内,但其作用机理及对生物体正常生理功能的影响还不清楚,因此研究稀土的生物效应是一个迫切需要解决的重要基础课题。本文采用现代核磁共振技术,通过分析灌胃给药0.2,2.0,10,20mg/kg 剂量的 La(NO_3)_3六个月后大鼠血清中某些内源性化合物的变化研究了稀土化合物在动物体内的作用情况及长期毒性,同时对20mg/kg 剂量组三个月后大鼠尿液的 H NMR 谱图进行了分析,并通过血液中一些重要生化指标的测定对结果进行了验证。图1(a)为正常大鼠血清的 H NMR 谱,图1(b)为给药(10mg La(NO_3)_3/kg)六个月后大鼠血清的 H NMR 谱图。从图中一些内源性化合物的物种和浓度的变化可以看出,稀土在体内长期作用后,可能导致动物肝脏和肾脏物特定部位受到了一定程度的损害,并使体内酶代谢发生紊乱,且随着稀土量的增多,损害程度也越严重。另外通过20mg La(NO_3)_3/kg 组三个月后大鼠尿液的 H NMR 分析及血液中生化指标的检测结果也可得出动物机体受损的信息。本方法也可应用于非先天疾病的异常代谢的临床检测及其它药...

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合成了两种新的DTPA双酰胺衍生物,DTPA-BDMA和DTPA-BDEA.通过~1HNMR滴定研究发现这两种化合物的质子解离过程为:中部胺基(PH<0.5),端部羧基(0.5<PH<3.1),中部羧基(3.1<pH<5.4),端部胺基(5.4<pH<8.5)和中部胺基(8.5<pH<12.5).在质子解离过程中端部胺基上的一个质子能转位到中部胺基上,同时分子结构将发生较大变化。Gd(DTPA-BDMA)和Gd(DTPA-BDEA)的弛豫效率分别为4.01和4.97L·mmol-1.s-1(400MHz,pH=7.3,25℃),说明这两种化合物是非常有应用前景的MRI造影剂.