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On the basis of total acid hydrolysis, methylation analysis, periodate oxidation and NMR studies (1H and 13C) the structure of the repeating unit of the polysaccharide was assigned and indicated only α-(1→4) linked Glucan.
      
The stereo-structures of Roridin P and Isororidin P were established on the basis of one- and two-dimensional nuclear magnetic resonance (NMR) spectral analyses.
      
The aim of this study was to synthesize and identify 2,4-dihalogenofluorobenzene (or trihalogenobenzene) derivatives by spectroscopic means, 1H-NMR and 19F-NMR.
      
The synthesized compounds have been characterized on the basis of elemental analyses, infrared spectroscopy (IR), and nuclear magnetic resonance (NMR).
      
Two compounds were designed, synthesized, and characterized by 1H-nuclear magnetic resonance (1H-NMR), ultraviolet (UV)-visible, and matrix-assisted laser desorption/ionization (MALDI) mass spectra.
      
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This paper reports the structural elucidation of securinine, a lactonic alkaloid of composition C_(13)H_(15)O_2N (VII; for formulas, see the Chinese text). Hydrogenation of securinine showed the presence of two double bonds, the attendant shifts of infrared carbonyl absorption being indicative of a conjugated five-membered lactone. Alkali fusion of securinine furnished a 63% yield of o-hydroxyphenylacetic acid (I), which was later found to be obtainable under much milder conditions. Combined with ultraviolet...

This paper reports the structural elucidation of securinine, a lactonic alkaloid of composition C_(13)H_(15)O_2N (VII; for formulas, see the Chinese text). Hydrogenation of securinine showed the presence of two double bonds, the attendant shifts of infrared carbonyl absorption being indicative of a conjugated five-membered lactone. Alkali fusion of securinine furnished a 63% yield of o-hydroxyphenylacetic acid (I), which was later found to be obtainable under much milder conditions. Combined with ultraviolet (255mμ, log e 4.2) and NMR (Fig. 1) evidence, partial structure II can be advanced, since pKa values precluded the possibility of III. As seen from the molecular formula, securinine should be tetracyclic. The failure to detect simple aldehydes or ketones (except for a low yield of glyoxal) from ozonolysis as well as the absence of N- and C-methyl groups strongly indicated the tertiary amino nitrogen (no N-H band) to be shared by two rings. Securinine and tetrahydrosecurinine (IX) can be dehydrogenated with mercuric acetate, the amounts of mercurous acetate precipitate corresponded to the introduction of one double bond. Partial formulas IV to VI were considered for the bicyclic hetero-rings, since bridged structures would violate Bredt's rule. Smaller hetero-rings failed to account for the stability of securinine upon prolonged refluxing in conc. hydrochloric acid, while larger rings were out of the question with a total of only 13 carbon atoms. Since tetrahydrosecurinine can be oxidized to give a six (or higher)-membered lactam (IR 6.01μ), partial structure VI had to be discarded. Partial structure IV had to share five carbon atoms of II while the latter can donate a maximum of four. This leaves V as the only alternative, leading to VII as the proposed complete structure. Formation of I from VII can be rationalized as the result of decomposition of XI through a reversed Mannich-type process. Lithium aluminum hydride reduction of securinine gave securininediol (XIII), which furnished salicylic acid (XV) upon alkali fusion. This can be regarded as a mechanistically similar process. The nitrogen-containing fragment from alkali fusion of securinine has been identified as △'-tetrahydropyridine (XII) via hydrogenation to piperidine. Hofmann degradation of securinine methiodide (XVI) gave o-hydroxyphenylacetic acid (I) and N-methyltetrahydropyridine XVII. These two pieces of evidence constitute conclusive proof of our proposed structure VII. The NMR spectrum was discussed. Diamagnetic shielding of C10 proton (7.1τ) by the double bond allowed the assignment of relative configurations as shown by Ⅶa. The proposal of Ⅶa as representing the absolute configuration, however, is to be regarded as highly speculative. During the draft of this paper, a short communication1181 came to our notice which proposed the same structure for securinine after degradative studies along different lines of attack.

通过光谱及化学降解数据,提出一叶荻碱(securinine)的结构式为VII.其相对构型可能如VIIa所示.并提出假说:VIIa可能亦表示其绝对构型.

Gentianidine(C_9H_9O_2N) is a new alkaloid isolated from the Chinese drug "Chin-Chiu" —Gentiania macrophylla. It is a lactonic tertiary base and is optically inactive. The infrared spectrum of gentianidine showed the presence of an a,β-unsaturated δ-lactone and C-methyl group(s). Oxidation of gentianidine with potasium permaganate in 1N sodium hydroxide produced berberonic acid (Ⅱ), identical with an authenic sample obtained from the oxidation of berberine. According to these results, two possible structures...

Gentianidine(C_9H_9O_2N) is a new alkaloid isolated from the Chinese drug "Chin-Chiu" —Gentiania macrophylla. It is a lactonic tertiary base and is optically inactive. The infrared spectrum of gentianidine showed the presence of an a,β-unsaturated δ-lactone and C-methyl group(s). Oxidation of gentianidine with potasium permaganate in 1N sodium hydroxide produced berberonic acid (Ⅱ), identical with an authenic sample obtained from the oxidation of berberine. According to these results, two possible structures for gentianidine, Ⅲ and Ⅳ, can be advanced. Comparison of NMR spectra of gentianidine and gentianine precluded structure Ⅳ, leaving Ⅲ as the favoured alternative. Proof of structure for gentianidine by synthesis was accomplished by treatment of the condensation product from 4,6-dimethylnicotinic acid and formaldehyde with 2N HCl at 100°for 17 hours.

通过光谱、化学降解及合成,证明秦艽乙素(Gentianidine)的结构式为(Ⅲ)。

ABSTRACT The synthesis of 5-substituted 3-methylmercapto-6-methyl-1,2,4-triazines by substitution reactions of N-[5′-(3′-methylmercapto-6′-methyl)-1′,2′,4′-triazinyl]pyridinium chloride (Ⅱ) was reported.On passing hydrogen sulfide into a suspension of compound (Ⅱ) in pyridine at room temperature,or on adding an aqueous solution of sodium hydrogen sulfide previously saturated with hydrogen sulfide to an aqueous solution of compound (Ⅱ),3-methylmercapto-5-mercapto-6-methyl-1,2,4-triazine (Ⅲ) resulted.When hydrogen...

ABSTRACT The synthesis of 5-substituted 3-methylmercapto-6-methyl-1,2,4-triazines by substitution reactions of N-[5′-(3′-methylmercapto-6′-methyl)-1′,2′,4′-triazinyl]pyridinium chloride (Ⅱ) was reported.On passing hydrogen sulfide into a suspension of compound (Ⅱ) in pyridine at room temperature,or on adding an aqueous solution of sodium hydrogen sulfide previously saturated with hydrogen sulfide to an aqueous solution of compound (Ⅱ),3-methylmercapto-5-mercapto-6-methyl-1,2,4-triazine (Ⅲ) resulted.When hydrogen sulfide was passed into a suspension of compound (Ⅱ) in pyridine at 90--95°,substitution reactions took place both at C_3 and C_5 positions with the formation of 3,5-dimercapto-6-methyl-1,2,4-triazine (Ⅳ).Both compounds Ⅲ and Ⅳ could be methylated with methyl iodide in aqueous sodium hydroxide solution to the same 3,5-dimethylmercapto-6-methyl-1,2,4-triazine (Ⅴ). Compound Ⅱ reacted with ο-cresol,m-cresol,phenol,m-nitrophenol,ο-nitrophenol or p-nitrophenol in aqueous pyridine at room temperature to give the corresponding 3-methyl- mercapto-5-substituted phenoxy-6-methyl-1,2,4-triazines (Ⅶ_(a-f)) (Table 1).Compound (Ⅱ) reacted with thiophenol in aqueous pyridine to give 3-methylmercapto-5-phenylmercapto-6-methyl-1,2,4-triazine (Ⅷ),and with absolute ethanol in pyridine to 3-methylmercapto-5-ethoxy-6-methyl-1,2,4-triazine (Ⅸ).Compound (Ⅱ) reacted in aqueous pyridine at room temperature with 3-ethylmercapto-5-mercapto-6-methyl-1,2,4-triazine (Ⅲ) to form S-[5′-( 3′-methylmercapto-6′-methyl)-1′,2′, 4′-triazinyl]-3-methylmercapto-5-mercapto-6-methyl-1,2,4-triazine (Ⅻ);with 3-methylmercapto-5-oxo-6-methyl-4,5-dihydro-1,2,4-triazine (Ⅰ) to N~4-[5′-(3′-methylmercapto-6′-methyl)-1′,2′,4′-triazinyl]-3-methylmercapto-5-oxo-6-methyl-4,5-dihydro-1,2,4-triazine (ⅩⅧ);with 3-methylmercapto-5-oxo-4,5-dihydro-1,2,4-triazine (ⅪⅩ) to N~4-[5′-(3′-methylmercapto-6′-methyl)-1′,2′,4′-triazinyl]-3-methylmercapto-5-oxo-4,5-dihydro-1,2,4-triazine (ⅩⅩ);with ethyl 3-methylmercapto-5-oxo-4,5-dihydro-1,2,4-triazine-6-carboxylate (ⅩⅩⅢ) to ethyl N~4-[5′-(3′-methylmercapto-6′-methyl)-1′,2′,4′-triazinyl] -3-methylmercapto-5-oxo-4,5-dihydro-1,2,4-triazine-6-carboxylate (ⅩⅪⅤ);and with quinazolone-4 (ⅩⅩⅦ) to give N3~- [ 5′-(3′-methylmercapto-6′-methyl)-1′,2′,4′-triazinyl] -4-oxo-3,4-dihydroquinazoline (ⅩⅩⅤⅢ).The structures of these compounds were elucidated by hydrolysis,aminolysis,infrared spectra,ultraviolet spectra and NMR spectra. When 3-methylmercapto-5-p-nitrophenoxy-6-methyl-1,2,4-triazine (Ⅶ_f) was refluxed with aniline or p-toluidine in ethanol,the addition compounds of p-nitrophenol and the corresponding 3-methylmercapto-5-substituted anilino-6-methyl-1,2,4-triazines (X_(a,b)) were obtained.The addition compounds could be decomposed with sodium hydroxide to p-nitrop-henol and the corresponding 3-methylmercapto-5-substituted anilino-6-methyl-1,2,4-triazines (Ⅺ_(a,b)).

氯化N-[5′-(3′-甲硫基-6′-甲基)-1′,2′,4′-三嗪基]吡啶?盐(Ⅱ)在吡啶中于室温通入硫化氢或与硫化氢饱和的硫氢化钠反应,均得到3-甲硫基-5-巯基-6-甲基-1,2,4-三嗪(Ⅲ);于较高温度与硫化氢反应,得3,5-二巯基-6-甲基-1,2,4-三嗪(Ⅳ).二者均可于氢氧化钠溶液中与碘甲烷反应,得到3,5-二甲硫基-6-甲基-1,2,4-三嗪(Ⅴ).Ⅱ在呲啶水溶液中与邻甲苯酚、闻甲苯酚、苯酚、间硝基苯酚、邻硝基苯酚或对硝基苯酚作用,得到相应的5-取代苯氧基化合物(Ⅶ_(a-f));与硫酚作用,得5-苯硫基化合物(Ⅷ);在吡啶中与无水乙醇作用,得5-乙氧基化合物(Ⅸ).化合物Ⅱ在吡啶水溶液中与Ⅲ作用,得S-[5′-(3′-甲硫基-6′-甲基)-1′,2′,4′-三嗪基]-3-甲硫基-5-巯基-6-甲基-1,2,4-三嗪(Ⅻ);与3-甲硫基-5-氧代-6-甲基-4,5-二氢-1,2,4-三嗪(Ⅰ)作用,得N~4_[5′-(3′-甲硫基-6′-甲基)-1′,2′,4′-三嗪基]-3-甲硫基-5-氧代-6-甲基-4,5-二氢-1,2,4-三嗪(ⅩⅧ);与3-甲硫基-5-氧代-4,5-二氢-1,2,...

氯化N-[5′-(3′-甲硫基-6′-甲基)-1′,2′,4′-三嗪基]吡啶?盐(Ⅱ)在吡啶中于室温通入硫化氢或与硫化氢饱和的硫氢化钠反应,均得到3-甲硫基-5-巯基-6-甲基-1,2,4-三嗪(Ⅲ);于较高温度与硫化氢反应,得3,5-二巯基-6-甲基-1,2,4-三嗪(Ⅳ).二者均可于氢氧化钠溶液中与碘甲烷反应,得到3,5-二甲硫基-6-甲基-1,2,4-三嗪(Ⅴ).Ⅱ在呲啶水溶液中与邻甲苯酚、闻甲苯酚、苯酚、间硝基苯酚、邻硝基苯酚或对硝基苯酚作用,得到相应的5-取代苯氧基化合物(Ⅶ_(a-f));与硫酚作用,得5-苯硫基化合物(Ⅷ);在吡啶中与无水乙醇作用,得5-乙氧基化合物(Ⅸ).化合物Ⅱ在吡啶水溶液中与Ⅲ作用,得S-[5′-(3′-甲硫基-6′-甲基)-1′,2′,4′-三嗪基]-3-甲硫基-5-巯基-6-甲基-1,2,4-三嗪(Ⅻ);与3-甲硫基-5-氧代-6-甲基-4,5-二氢-1,2,4-三嗪(Ⅰ)作用,得N~4_[5′-(3′-甲硫基-6′-甲基)-1′,2′,4′-三嗪基]-3-甲硫基-5-氧代-6-甲基-4,5-二氢-1,2,4-三嗪(ⅩⅧ);与3-甲硫基-5-氧代-4,5-二氢-1,2,4-三嗪(ⅪⅩ)作用,得N~4-[5′-(3′-甲硫基-6′-甲基)-1′2′4′-三嗪基]-3-甲硫基-5-氧代-4,5-二氢-1,2,4-三嗪(ⅩⅩ);与3-甲硫基-5-氧代-4,5-二氢-1,2,4-三嗪-6-羧酸乙酯(ⅩⅩⅢ)作用,得N~4_[5′-(3′-甲硫基-6′-甲基)-1′,2′,4′-三嗪基]-3-甲硫基-5-羰基-4,5-二氢-1,2,4-三嗪-6-羧酸乙酯(ⅩⅪⅤ);与喹唑酮-4(ⅩⅩⅦ)作用,得N~3_[5′-(3′-甲硫基-6′-甲基)-1′,2′,4′-三嗪基]-4-氧代-3,4-二氢喹唑啉(ⅩⅩⅧ).这些化合物的结构系通过其水解反应、胺解反应、红外吸收光谱、紫外吸收光谱或核磁共振谱等研究予以证明.3-甲硫基-5-对硝基苯氧基-6-甲基-1,2,4-三嗪(Ⅶ_f)与苯胺或对甲苯胺反应,得到3-甲硫基-5-取代苯胺基-6-甲基-1,2,4-三嗪对硝基苯酚复合物(X_(a,b).后者用碱处理,得3-甲硫基-5-取代苯胺基-6-甲基-1,2,4-三嗪(Ⅺ_(a,b)及对硝基苯酚.

 
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