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1.
Issa Yavari Loghman Moradi Farough Nasiri Hoorieh Djahaniani 《Monatshefte für Chemie / Chemical Monthly》2005,36(9):1757-1761
The regioselective reaction of N1-benzyl-N2-(4-nitrophenyl)ethanediamide with dialkyl acetylenedicarboxylates or alkyl propiolates in the presence of triphenylphosphine
leads to dialkyl 4-benzylamino-1-(4-nitrophenyl)-5-oxo-2,5-dihydro-1H-pyrrole-2,3-dicarboxylates or alkyl 4-benzylamino-1-(4-nitrophenyl)-2-oxo-5-pyrrolidinecarboxylates in good yields. 相似文献
2.
Paramasivam Parthiban Mannangatty Rani Senthamaraikannan Kabilan 《Monatshefte für Chemie / Chemical Monthly》2009,49(3):287-301
Abstract A series of variously substituted N-methylpiperidin-4-one-O-benzyloximes were synthesized by three different methods. Among them, the direct conversion of 2,6-diarylpiperidin-4-ones
into the corresponding oxime ethers (method A) was proved to be better than the other two methods in the sense of good yield,
convenience, easy work-up and quick reaction time. All the synthesized compounds are characterized by IR, Mass and NMR (1H NMR, 13C NMR, 1H-1H COSY, 1H-13C COSY and HMBC) spectral studies. The conformational preference of the synthesized oxime ethers with/without alkyl and aryl
substituents at C-3/C-5 and C-2/C-6 is discussed using the spectral data. The observed chemical shifts and coupling constants
suggest that the synthesized oxime ethers adopt chair conformation with equatorial orientation of all the substituents, whereas
1-methyl-3-isopropyl-2,6-diphenylpiperidin-4-one-O-benzyloxime also exists in boat conformation. Based on the NMR data, the effects of oximination on ring carbons and their
associated protons and alkyl substituents are discussed. In addition, the effect of NMe group on the 2,6-diarylpiperidin-4-one-O-benzyloximes was also studied.
Graphical abstract
相似文献
3.
M. S. Klenov A. M. Churakov O. V. Anikin Yu. A. Strelenko V. A. Tartakovsky 《Russian Chemical Bulletin》2009,58(10):2047-2057
Salts of N-nitro-O-(4-nitrophenyl)hydroxylamine were synthesized by a new method of oxidative nitration, involving the reaction of O-(4-nitrophenyl)hydroxylamine with KNO2 or NaNO2 in the presence of PhI(OAc)2 or PhIO as oxidants. When using Na15NO2, the samples containing the nitro group labeled with the 15N isotope were obtained. Acidification of the appropriate salt gave N-nitro-O-(4-nitrophenyl)hydroxylamine. It is the first N-nitrohydroxylamine isolated in the H-form. Its thermal stability was investigated and the probable mechanism of decomposition
was suggested. From a comparison of the 14N and 15N NMR spectra of N-nitro-O-(4-nitrophenyl)hydroxylamine with those of its O- and N-methylated derivatives, its equilibrium with the aci-form (N=NOOH) was inferred. 相似文献
4.
E. V. Kondrashov E. V. Rudyakova G. N. Rozentsveig I. B. Rozentsveig K. A. Chernyshev L. B. Krivdin G. G. Levkovskaya 《Russian Journal of Organic Chemistry》2009,45(9):1365-1374
N-(Trifluoromethylsulfonyl) and N-arylsulfonyl polychloroacetaldehyde imines reacted with pyrrole, 1-alkyl-, 1-benzyl-, and 1-(4-nitrophenyl)-substituted pyrroles,
and bis-pyrroles to give the corresponding 2-[1-(sulfonylamino)polychloroethyl]-1H-pyrroles or mixtures of 2- and 3-[1-(sulfonylamino)polychloroethyl]-1H-pyrroles, depending on the nature of the Schiff base and substituent on the pyrrole nitrogen atom and reaction conditions.
The first synthesis of 2,5-disubstituted NH-pyrrole by reaction of pyrrole with Schiff bases was described. 相似文献
5.
Phase transitions of poly(N-isopropylacrylamide-co-acrylic acid) (PiPA-AA) and poly(N,N- diethylacrylamide-co-acrylic acid) (PdEA-AA) in water have been investigated by means of turbidimetry, Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC). The phase transition temperatures (Tp) of these copolymers increase with the degree of ionization () of the acrylic acid (AA) units, which in turn is dependent on the pH of the solutions. Apparent values of pKa for the AA units, determined from the pH dependencies of Tp, are 4.7 and 5.4 for PiPA-AA and PdEA-AA, respectively. Differences between Tp for PiPA-AA and Tp for PiPA homopolymer (Tp) are +1.5 and –0.2 °C/mol% of AA at =1 and 0, respectively. The values of Tp for PdEA-AA are +2.6 (ionic) and –0.5 (nonionic)°C/mol%, indicating that the incorporated AA units have a larger effect on PdEA than on PiPA. DSC measurements performed with each of these copolymers at different pH values show a linear relationship between Tp and the enthalpy of transition (H). IR measurements of PiPA-AA show that the profiles of IR bands from both iPA and AA units exhibit critical changes at Tp of the copolymer. Heating the solution above Tp leads to shifts of the amide II, C–H stretch, and C–H bend bands from the iPA units toward lower wavenumbers, as well as a shift of the amide I band from the iPA units toward higher wavenumbers. A decrease in the intensity of the symmetric C=O stretch IR band from carboxylate anions (1560 cm–1), and an increase in the intensity of the C=O stretch band from COOH groups (1705 cm–1) suggest that a partial protonation of the carboxylate groups (COO–+H+COOH) takes place upon the phase transition. 相似文献
6.
V. A. Pal’chikov I. N. Tarabara I. V. Omel’chenko O. V. Shishkin L. I. Kas’yan 《Russian Journal of Organic Chemistry》2010,46(6):823-829
Acylation of N-substituted exo-2-hydroxy-5-oxo-4-oxatricyclo[4.2.1.03,7]nonane-endo-9-carboxamides on heating in boiling glacial acetic acid gave the corresponding trans-diacetoxy imides of the norbornane series. The effect of the reaction time on the product composition was studied in the
reaction with exo-2-hydroxy-N-(4-methylphenyl)-5-oxo-4-oxatricyclo[4.2.1.03,7]nonane-endo-9-carboxamide. The structure of the resulting norbornane-2,3-dicarboximides was confirmed by IR, 1H NMR, and mass spectra, and the structure of N-(2,5-dimethylphenyl)-exo-2,endo-3-diacetoxybicyclo[2.2.1]heptan-endo-5,endo-6-dicarboximide was additionally proved by X-ray analysis. 相似文献
7.
Electrochemical measurements including cyclic voltammetry, differential capacity, and chronocoulometry have been used to characterize the adsorption behaviors of the zwitterionic surfactant
N-dodecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate (DDAPS) on the Au(111) electrode surface. The thermodynamics of the ideally polarized electrode have been employed to determine the Gibbs excess and the Gibbs energy of adsorption. The results show that the adsorption of DDAPS has a multistate character. The first two states are observed at potentials close to zero charge. At low bulk DDAPS concentrations, it corresponds to the formation of a film of nearly flat adsorbed molecules. At higher concentrations it is converted into a hemimicellar state. The second state is formed at negative potentials and charge densities close to 0 C cm–2. It corresponds to a film of tilted molecules oriented with the hydrocarbon tail towards the metal and the polar head toward the solution.Dedicated to Professor Zbigniew Galus on the occasion of his 70th birthday and in recognition of his many contributions to electrochemistry. 相似文献
8.
Dupard-Julien CL Kandlakunta B Uppu RM 《Analytical and bioanalytical chemistry》2007,387(3):1027-1032
A reversed-phase, high-performance liquid chromatography (RP-HPLC) method that allows quantitation of low levels of epoxides
has been described. The method involved derivatization of epoxides using 100- to 1,000-fold excess N,N-diethyldithiocarbamate (DTC) at 60 °C for 20 min at neutral pH. The unreacted DTC was then decomposed to CS2 and diethyl amine by acidification of the reaction mixture to pH 2 using orthophosphoric acid. The first two steps could
be performed in the same reaction vessel by sequential addition of reagents. In the final step, an aliquot (20 μL) of the
derivatized sample was analyzed for the presence of stable esters of DTC by RP-HPLC using a Supelcosil LC-18-S (150 × 4.6-mm)
column and a mobile phase consisting of 40% (v/v) acetonitrile in water at a flow of 1 mL min−1. Using UV detection at 278 nm, the epoxides gave linear responses in the concentration range of 0.25 to 50 μM. The method
is robust, and as low as 5 pmol of the analyte could be successfully detected and quantified with recoveries of ≥94%. Following
a minimal pretreatment such as ultrafiltration (molecular weight cutoff 5,000 Da), the method is suitable for analysis of
epoxides in complex physiological fluids (e.g., fetal bovine serum). The method has been rigorously evaluated and adapted
in our laboratory for routine analysis and determination of stability of epoxides of 1,3-butadiene and other alkenes added
to cell cultures. 相似文献
9.
M. Madesclaire V. P. Zaitsev J. V. Zaitseva S. Kh. Sharipova 《Chemistry of Heterocyclic Compounds》2007,43(10):1325-1332
A synthesis is reported for (4R,5R)-and (4S,5S)-4-hydroxymethyl-5-(4-nitrophenyl)oxazolidin-2-ones and (1′R,4R)-and (1′S,4S)-4-[hydroxy(4-nitrophenyl)methyl]oxazolidin-2-ones from (1R,2R)-and (1S,2S)-2-amino-1-(4-nitrophenyl)-1,3-propanediols. The effect of the experimental conditions on the formation of these compounds
was studied.
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1562–1570, October, 2007. 相似文献
10.
R. I. Kublashvili M. O. Labartkava K. P. Giorgadze D. Sh. Ugrekhelidze 《Chemistry of Natural Compounds》2008,44(4):413-415
N-Tolylglycosylamines were synthesized from o-, m-, and p-toluidines and aldoses (D-glucose, D-galactose, D-mannose, L-rhamnose, D-xylose, and L-arabinose). The anomeric and isomeric
compositions of the synthesized products were established using 13C NMR methods.
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Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 333–335, July–August, 2008. 相似文献
11.
Victor V. Dotsenko Sergey G. Krivokolysko Victor P. Litvinov 《Monatshefte für Chemie / Chemical Monthly》2008,139(3):271-275
Summary. Ethyl 2-(N-morpholinyl)cyclopent-1-ene-1-carboxylate reacted smoothly with cyanothioacetamide to give morpholinium 4-cyano-1-oxo-2,5,6,7-tetrahydro-1H-cyclopenta[c]pyridine-3-thiolate; the former when treated with N-benzyl-α-chloroacetamide gave either a S-alkyl derivative or cyclopenta[d]thieno[2,3-b]pyridine, depending on the reaction conditions. Under Mannich-type aminomethylation with primary amines and formaldehyde the above thiolate afforded derivatives of the previously unknown
heterocyclic system, cyclopenta[g]pyrido[2,1-b][1,3,5]thiadiazine in 81–90% yields.
Victor P. Litvinov, was Deceased
Victor P. Litvinov, This paper is dedicated to the blessed memory of our colleague, Prof. Victor Petrovich Litvinov (Dec 24,
1932–Feb 26, 2007) 相似文献
12.
Katsuhiro Inomata Reina Doi Erina Yamada Hideki Sugimoto Eiji Nakanishi 《Colloid and polymer science》2007,285(10):1129-1137
Amphiphilic polymers Cn-PHEG consisting of water-soluble poly[N
5-2-(hydroxyethyl) l-glutamine] (PHEG) and hydrophobic alkyl chain (carbon number n = 12, 14, 16, or 18) attached at the PHEG terminal was prepared, and association behavior and structure of associate for
Cn-PHEG in selective solvent (water/ethylene glycol mixed solvent) have been investigated. α-Helix content of PHEG block for
all the polymers increased with weight fraction of ethylene glycol in the mixed solvent (W
EG). By light scattering measurements, formation of a small micelle was suggested for C14-, C16-, and C18-PHEG when W
EG = 0. With the increase in W
EG, appearance of a larger associate was revealed for C16- and C18-PHEG. Evaluated molecular weight and radius of gyration suggested
that the micelle is star-like sphere when W
EG = 0 and worm-like cylinder when W
EG = 0.7. C12-PHEG did not demonstrate any distinct micellization behavior because of the weak hydrophobicity of C12 chain. 相似文献
13.
Group-theoretical and quantum-chemical investigations of the spectrum of low-lying excited states have been performed by the ROHF and FCI-RAS (Full CI in Restricted Active Space) methods for 3d metal endofullerenes (MEFs) M@C60 (M =Mn, Cr, and Fe) in different charged states. The major purpose of this study is quantum-chemical verification of the anomalous (“non-Bethe’s”) character of splitting of the d N atomic states in an electrostatic field with icosahedral symmetry, predicted previously within the theory of integral invariants theory. The interrelation between the integral invariants theory and the quantumchemical methods applied in this work is considered in detail. Our calculations suggest that the d N atomic states in the icosahedral field generated by fullerene C60 (I h ) on a metal atom (ion) remain non-split for different charged states of the metal and C60. Reasons for this phenomenon and other possible approaches to verification of the prediction are discussed. It is demonstrated that the d N states of the encapsulated metal are split in icosahedral 3d MEFs only under very strong compression of these structures. 相似文献
14.
A structure and kinetic stability study on some complexes with the general formula MN5, where M are the alkali-metal atoms, Li, Na, K, and Rb, has been carried by using hybrid density functional methods. Complex B (C2v) with two points of attachment to the N5 ring is the most energetically favored for all metals considered here. Pyramidal structures A (C5v) are kinetically unstable and they rapidly rearrange to the most stable planar structures B. At the QCISD(T)/6-311 + G*//B3LYP/6-311 + G* + ZPE (B3LYP/6-311 + G*) level, the decomposition barrier heights of LiN5-B, NaN5–B, KN5-B, and RbN5-B are predicted to be 19.9, 22.0, 22.5, and 23.0 kcal/mol, respectively. In addition, the rate constants of the decomposition reaction MN5-B MN3 + N2 (M + Li, Na, K, and Rb) are also predicted using conventional transition state theory and canonical variational transition state theory, respectively. 相似文献
15.
Amphiphilic diblock copolymers consisting of 2-(N, N-dimethylamino)ethyl methacrylate (DMAEMA, abbreviated as DMA) and stearyl methacrylate (SMA) with different degrees of polymerization
and compositions were prepared by reversible addition–fragmentation chain transfer (RAFT) copolymerization. The composition
and chemical structures of (co)polymers were confirmed by the measurements of 1H NMR spectroscopy and gel permeation chromatography (GPC). The self-aggregating structures of amphiphilic diblock copolymers
with the concentration of 0.1~0.3 wt.% in THF/water mixed solvent was investigated by transmission electron microscopy (TEM)
and dynamic light scattering (DLS). It was found that both the morphologies and aggregating particle size resulted from the
amphiphilic diblock copolymers depended on the variation of pH values, the lengths of the hydrophobic PSMA chains, and the
weight ratio of THF/water mixed solvent. 相似文献
16.
V. N. Britsun A. N. Borisevich V. B. Pirozhenko M. O. Lozinskii 《Russian Journal of Organic Chemistry》2007,43(2):276-279
Direction of a reaction between 3-oxo-3-R1-N-R2-propanethioamides and 2-amino-5-R-pyridines in acetic acid depends on the structure of initial thioamides: at R1 = Me, R2 = Ar, Et 2-methyl-7-R-4H-pyrido[1,2-a]-pyrimidine-4-thiones are obtained, and at R1 = Ar, R2 = Me form 1-methyl-5-(N-methylaminothiocarbonyl)-4,6-diaryl-1,2-dihydropyridine-2-thiones. 相似文献
17.
Summary. An efficient synthesis of trialkyl N-alkyl-6-methyl-2-pyridone-3,4,5-tricarboxylates from three-component reaction of the zwitterions generated from dialkyl acetylenedicarboxylates
and alkyl isocyanides with alkyl 2-chloroacetoacetates is described. 相似文献
18.
Victor V. Dotsenko Sergey G. Krivokolysko Victor P. Litvinov 《Monatshefte für Chemie / Chemical Monthly》2008,139(6):657-661
Morpholinium 3-cyano-4-methyl-6-oxo-1,6-dihydropyridine-2-thiolate upon treatment with primary amines and a formaldehyde excess
under mild conditions produces bis(pyrido[2,1-b][1,3,5]thiadiazin-7-yl)methane derivatives in good yields (67–87%).
Correspondence: Victor V. Dotsenko, State Enterprise “Luganskstandartmetrology”, 91021 Lugansk, Ukraine. 相似文献
19.
V. U. Khuzhaev I. Zh. Zhalolov M. G. Levkovich S. F. Aripova A. S. Shashkov 《Russian Chemical Bulletin》2004,53(8):1765-1767
The structure of a new dimeric indole alkaloid, arundarine, isolated from the roots of the plant Arundo donax L. (Poaceae) was determined. On the basis of spectroscopic data, arundarine was identified as 5-[3-(2-dimethylaminoethyl)indol-1-yl]-6-hydroxy-N
2-methyl-1,2,3,4-tetrahydro--carboline.Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1697–1699, August, 2004.For Part 14, see Ref. 1. 相似文献
20.
V. E. Romanov E. E. Shul’ts M. M. Shakirov G. A. Tolstikov 《Chemistry of Natural Compounds》2008,44(3):346-351
New N-acylates of the norditerpenoid alkaloid N-deacetyllappaconitine that were modified in the aromatic ring and are interesting as potential pharmacologically valuable
compounds were prepared.
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Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 275–279, May–June, 2008. 相似文献