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1.
《Magnetic resonance in chemistry : MRC》2002,40(11):738-742
An unsymmetrical heterocyclic diamine, 1,2‐dihydro‐2‐(4‐aminophenyl)‐4‐[4‐(4‐aminophenoxy)‐4‐phenyl]‐(2H)phthalazin‐1‐one, was synthesized. Its 1H and 13C NMR spectra were completely assigned by utilizing the two‐dimensional heteronuclear 13C–1H multiple‐bond coherence (HMBC) spectroscopy, and heteronuclear 13C–1H one‐bond correlation spectroscopy, homonuclear shift correlation spectroscopy (H,H‐COSY) and rotating frame Overhauser enhancement spectroscopy (ROESY). The structure of the compound was shown to be the phthalazinone rather than the phthalazine ether from cross peaks and chemical shifts of the protons. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
2.
Wei Zhang 《Magnetic resonance in chemistry : MRC》2013,51(7):431-434
A one‐step method was reported for the synthesis of 6‐acetamido‐3‐(N‐(2‐(dimethylamino) ethyl) sulfamoyl) naphthalene‐1‐yl 7‐acetamido‐4‐hydroxynaphthalene‐2‐sulfonate by treating 7‐acetamido‐4‐hydroxy‐2‐naphthalenesulfonyl chloride with equal moles of N, N‐dimethylethylenediamine in acetonitrile in the presence of K2CO3. The chemical structure of the obtained compounds was characterized by MS, FTIR, 1H NMR, 13C NMR, gCOSY, TOCSY, gHSQC, and gHMBC. The chemical shift differences of 1H and 13C being δ 0.04 and 0.2, respectively, were unambiguously differentiated. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
3.
Andrei V. Afonin Igor A. Ushakov Alexander V. Vashchenko Dmitry E. Simonenko Andrei V. Ivanov Alexander M. Vasil'tsov Al'bina I. Mikhaleva Boris A. Trofimov 《Magnetic resonance in chemistry : MRC》2009,47(2):105-112
According to the 1H, 13C and 15N NMR spectroscopic data and DFT calculations, the E‐isomer of 1‐vinylpyrrole‐2‐carbaldehyde adopts preferable conformation with the anti‐orientation of the vinyl group relative to the carbaldehyde oxime group and with the syn‐arrangement of the carbaldehyde oxime group with reference to the pyrrole ring. This conformation is stabilized by the C? H···N intramolecular hydrogen bond between the α‐hydrogen of the vinyl group and the oxime group nitrogen, which causes a pronounced high‐frequency shift of the α‐hydrogen signal in 1H NMR (~0.5 ppm) and an increase in the corresponding one‐bond 13C–1H coupling constant (ca 4 Hz). In the Z‐isomer, the carbaldehyde oxime group turns to the anti‐position with respect to the pyrrole ring. The C? H···O intramolecular hydrogen bond between the H‐3 hydrogen of the pyrrole ring and the oxime group oxygen is realized in this case. Due to such hydrogen bonding, the H‐3 hydrogen resonance is shifted to a higher frequency by about 1 ppm and the one‐bond 13C–1H coupling constant for this proton increases by ~5 Hz. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
4.
Valerie Huemer Gernot A. Eller Wolfgang Holzer 《Magnetic resonance in chemistry : MRC》2010,48(6):476-482
Various [5,6]pyrano[2,3‐c]pyrazol‐4(1H)‐thiones were synthesized in high yields by treatment of the corresponding [5,6]pyrano[2,3‐c]pyrazol‐4(1H)‐ones with Lawesson's reagent. Detailed NMR spectroscopic studies were undertaken of the title compounds. Complete and unambiguous assignment of chemical shifts (1H, 13C, 15N) and coupling constants (1H,1H; 13C,1H) was achieved by the combined application of various one‐ and two‐dimensional (1D and 2D) NMR spectroscopic techniques. Unequivocal mapping of most 13C,1H spin coupling constants is accomplished by 2D (δ, J) long‐range INEPT spectra with selective excitation. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
5.
N‐acetyl‐4‐nitrotryptophan methyl ester (2), N‐acetyl‐5‐nitrotryptophan methyl ester (3), N‐acetyl‐6‐nitrotryptophan methyl ester (4) and N‐acetyl‐7‐nitrotryptophan methyl ester (5) were synthesized through a modified malonic ester reaction of the appropriate nitrogramine analogs followed by methylation with BF3‐methanol. Assignments of the 1H and 13C NMR chemical shifts were made using a combination of 1H–1H COSY, 1H–13C HETCOR and 1H–13C selective INEPT experiments. Copyright © 2008 Crown in the right of Canada. Published by John Wiley & Sons, Ltd 相似文献
6.
《Magnetic resonance in chemistry : MRC》2003,41(11):908-920
Structure elucidation of compounds in the benzisoxazole series ( 1 – 6 ) and naphtho[1,2‐d][1,3]‐ ( 7 – 10 ) and phenanthro[9,10‐d][1,3]oxazole ( 11 – 14 ) series was accomplished using extensive 2D NMR spectroscopic studies including 1H–1H COSY, long‐ range 1H–1H COSY, 1H–13C COSY, gHMQC, gHMBC and gHMQC‐TOCSY experiments. The distinction between oxazole and isoxazole rings was made on the basis of the magnitude of heteronuclear one‐bond 1JC2, H2 (or 1JC3, H3) coupling constants. Complete analysis of the 1H NMR spectra of 11 – 14 was achieved by iterative calculations. Gradient selected gHMQC‐TOCSY spectra of phenanthro[9,10‐d][1,3]oxazoles 11 – 14 were obtained at different mixing times (12, 24, 36, 48 and 80 ms) to identify the spin system where the protons of phenanthrene ring at H‐5, H‐6 and at H‐9 and H‐7 and H‐8 were highly overlapping. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
7.
《Magnetic resonance in chemistry : MRC》2002,40(5):371-376
1H, 13C and two‐dimensional NMR analyses were applied to determine the NMR parameters of 6‐(2′,3′‐dihydro‐1′H‐inden‐1′‐yl)‐1H‐indene. The measurements were accomplished with 0.5 mg of the substance, this quantity being sufficient to determine the chemical shifts of all the H and C atoms, and also the appropriate coupling constants and to give the complete NMR resonance assignments of the molecule. The predicted patterns of the four different H atoms of the methylene groups of the indane structural element coincided completely with the complex patterns in the NMR spectra. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
8.
《Magnetic resonance in chemistry : MRC》2002,40(8):545-548
The 1H and 13C NMR resonances for 16 acridin‐9(10H)‐ones substituted with amino or (1,3‐benzothiazol‐2‐yl)amino groups were completely and unequivocally assigned by the concerted application of gs‐COSY, gs‐HMQC and gs‐HMBC experiments. Evidence for hydrogen bond and amino–imino tautomerism is presented for 1‐ and 4‐substituted acridin‐9(10H)‐ones. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
9.
《Magnetic resonance in chemistry : MRC》2003,41(9):747-749
We report the total assignments of the 13C and 1H NMR spectra of some 4‐methyl‐2‐oxo‐(2H)‐pyrido[1,2‐a]pyrimidine and 2‐methyl‐4‐oxo‐(4H)‐pyrido[1,2‐a]pyrimidine derivatives. The products were characterized by 1H and 13C NMR and reported data for similar compounds. No comparative data for the two sets of isomeric compounds with respect to 13C and 1H NMR have been reported to date. We made some detailed studies of the 2D NMR spectra of these compounds and observed that assignments made for non‐protonated carbon atoms by us and those reported in the literature for similar compounds need correction. The revised assignments were made on the basis of heteronuclear single quantum correlation (HSQC) and heteronuclear multiple bond correlation (HMBC) techniques. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
10.
《Magnetic resonance in chemistry : MRC》2003,41(9):703-708
Detailed solution‐NMR studies on the distorted ruthenium hydride complex [RuH(η6‐toluene)(Binap)](CF3SO3) (2) are reported. NOE‐spectroscopy, together with low‐temperature 1H and 31P NMR data, reveals restricted rotation around a P—C bond for a specific axial P—phenyl ring with the activation energy determined via simulation. From 19F, 1H HOESY data, the approach of the triflate anion relative to the hydride ligand is established. Comparison of the quadrupole coupling constant CQF from both solution‐ and solid‐state MAS‐NMR on the deuteride [RuD(η6‐benzene)(Binap)](CF3SO3) (1‐D) provide information on the nature of the Ru—H bond. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
11.
The cyclization of 1‐amino‐2‐mercapto‐5‐[5‐methyl‐1‐(4‐methylphenyl)‐1,2,3‐triazol‐4‐yl]‐1,3,4‐triazole with various α‐haloketone in absolute ethanol yields 7H‐3‐[5‐methyl‐1‐(4‐methylphenyl)‐1,2,3‐triazol‐4‐yl]‐6‐substituted‐s‐triazolo[3,4‐b]‐1,3,4‐thiadiazines and their structures are established by elemental analysis, MS, IR and 1H NMR spectral data. 相似文献
12.
《Magnetic resonance in chemistry : MRC》2003,41(12):1000-1008
The conformations of cis‐ ( 1 ) and trans‐cyclopentane‐1,3‐diol ( 2 ) have been studied by ab initio (Gaussian 98) and molecular mechanics (PCMODEL) calculations and by NMR spectroscopy. The calculations gave two low‐energy conformations for ( 1 ), 1A and 1B , both with axial hydroxyl groups. Two conformations with equatorial hydroxyl groups ( 1C and 1D ) were found but with much higher energy (ca 4.0 kcal mol?1). Five low‐energy conformers were found for 2 . Four were envelope conformations and one a half‐chair. The complete analysis of the 400 MHz 1H NMR spectra of 1 in a variety of solvents and 2 in chloroform was performed by extensive decoupling experiments, iterative computer analysis and spectral simulation. This gave all the H,H couplings in the molecule, including in 1 a long‐range 4J(H,H) coupling between H‐2cis and H‐4,5cis. The 3J(H,H) couplings were used to determine the conformer populations in these molecules. This was initially achieved using the Haasnoot, de Leeuw and Altona equation. to obtain the conformer couplings. It was found that this equation was not accurate for the C·CH2·CH2·C fragment in these molecules and the following equation was derived for this fragment from five‐ and six‐ membered cyclic compounds in fixed conformations: (1) The conformer populations were obtained by calculating the conformer couplings which were then compared with the observed couplings. Compound 1 in benzene solution is an approximately equal mixture of conformers 1A and 1B with small (<4%) amounts of 1C and 1D . In the polar solvents acetone and acetonitrile the populations of 1A and 1B are again equal, with 20% of 1C and <2% of 1D . In 2 the major conformers are 2B and 2D with small amounts of 2C , 2E and 2A . These novel findings are considered with previous data on cyclopentanol and cis‐ and trans‐cyclopentane‐1,2‐diol and it is shown that the axial hydroxyl substituent at the fold of the envelope appears to be a major factor in determining the conformational energies of these compounds. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
13.
Dionisia Sanz Almudena Perona RosaM. Claramunt Elena Pinilla M.Rosario Torres Jos Elguero 《Helvetica chimica acta》2006,89(7):1290-1303
The new N‐salicylideneheteroarenamines 1 – 4 were prepared by reacting the biologically relevant 3‐hydroxy‐4‐pyridinecarboxaldehyde ( 5 ) with 1H‐imidazol‐1‐amine ( 6 ), 1H‐pyrazol‐1‐amine ( 7 ), 1H‐1,2,4‐triazol‐1‐amine ( 8 ), and 1H‐1,3,4‐triazol‐1‐amine ( 9 ). Solution 1H‐, 13C‐, and 15N‐NMR were used to establish that the hydroxyimino form A is the predominant tautomer. A combination of 13C‐ and 15N‐CPMAS‐NMR with X‐ray crystallographic studies confirms that the same form is present in the solid state. The stabilities and H‐bond geometries of the different forms, tautomers and rotamers, are discussed by using B3LYP/6‐31G** calculations. 相似文献
14.
研究了室温下间苯二酚和甲基乙烯基酮分别与β-环糊精( β-CD)形成包结物后的几种不同固相反应,结果表明包结物A(间苯二酚/β-CD)与包结物B(甲基乙烯基酮/β-CD)反应能够很好地得到目的产物,产率及ee值分别为82.8%和78.4%;间苯二酚与包结物B反应仅得到低光学活性产物(ee值为19.5%);包结物A与甲基乙烯基酮反应却没有得到手性目的产物。以熔点、X-粉末衍射、固相核磁碳谱及ROESY多种方法对所形成的包结物进行了表征,包结物中主客体的比例(1:1)通过1H NMR (400 MHz)得以确定,文章对固相环加成反应的机制也进行了初步探讨。 相似文献
15.
A. S. Brar Rajeev Kumar 《Journal of polymer science. Part A, Polymer chemistry》2002,40(14):2225-2236
N‐vinyl‐2‐pyrrolidone/methyl acrylate (V/M) copolymers were prepared by free‐radical bulk polymerization using benzoyl peroxide as an initiator. The copolymer composition of these copolymers was calculated from 1H NMR spectra. The radical reactivity ratios for N‐vinyl‐2‐pyrrolidone (V) and methyl acrylate (M) were rV = 0.09, rM = 0.44. These reactivity ratios for the copolymerization of V and M were determined using the Kelen–Tudos and nonlinear least‐squares error‐in‐variable methods. The 13C{1H} and 1H NMR spectra of these copolymers overlapped and were complex. The complete spectral assignment of the 13C and 1H NMR spectra were done with distortionless enhancement by polarization transfer and two dimensional 13C‐1H heteronuclear single quantum correlation spectroscopic experiments. The two‐dimensional 1H‐1H homonuclear total correlation spectroscopic NMR spectrum showed the various bond interactions, thus inferring the possible structure of the copolymers. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2225–2236, 2002 相似文献
16.
A. S. Brar Rajeev Kumar 《Journal of polymer science. Part A, Polymer chemistry》2002,40(15):2717-2717
N‐vinyl‐2‐pyrrolidone/methyl acrylate (V/M) copolymers were prepared by free‐radical bulk polymerization using benzoyl peroxide as an initiator. The copolymer composition of these copolymers was calculated from 1H NMR spectra. The radical reactivity ratios for N‐vinyl‐2‐pyrrolidone (V) and methyl acrylate (M) were rV = 0.09, rM = 0.44. These reactivity ratios for the copolymerization of V and M were determined using the Kelen–Tudos and nonlinear least‐squares error‐in‐variable methods. The 13C{1H} and 1H NMR spectra of these copolymers overlapped and were complex. The complete spectral assignment of the 13C and 1H NMR spectra were done with distortionless enhancement by polarization transfer and two dimensional 13C‐1H heteronuclear single quantum correlation spectroscopic experiments. The two‐dimensional 1H‐1H homonuclear total correlation spectroscopic NMR spectrum showed the various bond interactions, thus inferring the possible structure of the copolymers. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2225–2236, 2002 相似文献
17.
《Magnetic resonance in chemistry : MRC》2002,40(7):467-470
In the course of saponification experiments with bis(2‐cyanoethyl) 2,6‐dimethyl‐4‐(2‐nitrophenyl)‐1,4‐dihydro‐3,5‐pyridinedicarboxylate ( 1 ), an analogue of the calcium channel blocker nifedipine, three unexpected degradation products were isolated. The compounds were identified as 3‐(2‐acetamido‐1‐carboxy‐1‐propenyl)‐1‐hydroxy‐2‐indolecarboxylic acid ( 3 ), 9‐hydroxy‐1,3‐dimethyl‐β‐carboline‐4‐carboxylic acid ( 4 ) and 6‐hydroxy‐2,4‐dimethyl‐5‐oxo‐5,6‐dihydrobenzo[c][2,7]naphthyridine‐1‐carboxylic acid ( 6 ). The structures of these compounds were deduced from one‐ and two‐dimensional 1H, 13C and natural abundance 15N NMR experiments (1H,1H‐COSY, gs‐HSQC, gs‐HMBC, 15N gs‐HMBC), and corroborated by comparison of their NMR data with the respective data for structurally similar compounds. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
18.
Eliška Procházková Lucie Čechová Petr Jansa Martin Dračínský 《Magnetic resonance in chemistry : MRC》2012,50(4):295-298
Four‐ and five‐bond heteronuclear J‐couplings between the hydrogen H‐8 and carbons C‐6 and C‐2 in a series of 7‐ and 9‐benzyl substituted purine derivaties with variuous substituents in positions 2 and 6 were studied by coupled 13 C NMR and H,C‐HMBC experiments and by DFT calculations. We have found that for some of the derivatives, the five‐bond coupling H8‐C2 is higher than the four‐bond H8‐C6 coupling, which is also evidenced by a stronger crosspeak in the HMBC. This finding contradicts the generally accepted opinion that only strong three‐bond crosspeaks and one weak four‐bond H8‐C6 crosspeak can be observed in the HMBC spectra of purine derivatives. The misinterpretation of HMBC spectra may lead to an incorrect determination of the purine derivatives' structure. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
19.
Nikolay S. Pivnenko Alexander V. Turov Vladimir V. Abakumov Lidiya A. Kutulya Svetlana V. Shishkina Oleg V. Shishkin 《Magnetic resonance in chemistry : MRC》2009,47(6):488-496
The structural characterization of two regioisomeric products of the interaction of 2,6‐bis‐(4‐methoxybenzylidene)‐3R‐methylcyclohexanone with methyl hydrazine was achieved using 1H NMR spectral data, including chemical shifts, coupling constants and results of COSY and nuclear overhauser effect (NOE) experiments. Configurations of the new chiral centers in the (3S,3aR,6R,7E)‐7‐(4‐methoxybenzylidene)‐3,4,5,7‐hexahydro‐3‐(4‐methoxyphenyl)‐2,6‐dimethyl‐ and 2,4‐dimethyl‐2H‐indazoles were assigned on the basis of experimental data combined with molecular modeling by the density functional theory (DFT) method. The distinction in the helical twisting power of studied compounds under addition to a nematic liquid crystal is discussed on the basis of peculiarities of the molecular structures. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
20.
《Magnetic resonance in chemistry : MRC》2002,40(7):477-479
We report the 1H NMR and 13C NMR chemical shifts and J(H,H), J(H,F) and J(C,F) coupling constants of 13 2,4‐diamino‐10‐methylpyrimido[4,5‐b]‐5‐quinolone derivatives, some of them with moderate activity against Plasmodium falciparum in vitro. They were characterized and assigned on the basis of 1H, 13C and 13C–1H (short‐ and long‐range) correlated spectra. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献