共查询到20条相似文献,搜索用时 15 毫秒
1.
L. G. Fedenok E. V. Plashchenyuk R. N. Myasnikova M. S. Shvartsberg 《Russian Chemical Bulletin》1996,45(3):667-670
Four pathways of synthesis of 1-(2-pyridyl)heptacosa-12,14-diyne, using 10-bromodecan-1-ol and acetylene or tetradec-1-yne and 2-methylbut-3-yn-2-ol along with -picoline as initial compounds, were studied and compared. It was shown that direct introduction of a completely formed unsaturated hydrocarbon chain into an -picoline molecule by alkylation of its lithium derivative is the most appropriate method for preparation of long-chain 2-alkadiynylpyridines.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 706–709, March, 1996. 相似文献
2.
Tatyana E. Glotova Igor A. Ushakov Olga N. Kazheva Oleg A. Dyachenko Boris A. Trofimov 《Tetrahedron》2009,65(47):9814-188
The one-pot reaction of natural amino acids (glycine, β-alanine, γ-aminobutyric and ?-aminocapronic acids, d,l-valine, d,l-leucine, anthranilic acid) with bielectrophilic acylacetylenes proceeds chemo-, regio- and stereospecifically in the presence of NaOH (45-50 °C, 4 h, EtOH-H2O) to give (after treatment of the reaction mixture with aqueous HCl) Z-isomers of N-acylvinyl derivatives of amino acids in 87-94% yield. 相似文献
3.
N. A. Orlova F. A. Zhuravlev V. V. Shelkovnikov T. N. Gerasimova 《Russian Chemical Bulletin》1995,44(6):1084-1086
A new method for synthesis of 1-[(2-acryloyloxyethyl)- and 1-[(2-propenyl)-2-(2-(1H)-quinolidene)-methyl]-1-ethylquinolinium iodides was proposed. The structures of the dyes obtained were studied by1H NMR spectroscopy.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1122–1124, June, 1995.This work was supported by the Russian Foundation for Basic Research (Project No. 93-02-3467) and the International Science Foundation (Grant RCO 000). 相似文献
4.
O. S. Filipenko S. M. Aldoshin G. V. Shilov N. I. Makarova V. A. Kharlanov M. I. Knyazhanskii 《Russian Chemical Bulletin》1995,44(2):287-292
The molecular structures of the initial compounds and the products of photocyclization involving amino and azomethine groups in perchlorates ofN-amino (1) andN-azomethine (2) derivatives of 2,4,6-triphenylpyridinium cations were studied. Cations1 and2 have an essentially non-coplanar arrangement of the -Ph rings, and the product of photocyclization of2, cation3, is characterized by a flattened structure. It was found that the orientation of the lone electron pair of the N atom with respect to one of the planes of the -Ph rings in molecule1 is more favorable for monocyclization involving the amino group. The structure of molecule2 allows two routes of the photoreaction,viz., O N proton transfer and monocyclization with an -Ph ring. However, the structural features of molecule2 are more favorable for photocyclization.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 296–301, February, 1995. 相似文献
5.
A simple, rapid and sensitive spectrophotometric method is described for the quantitative determination ofN-substituted phenothiazines. The method depends on the formation of a stable phenothiazine free radical cation by the use ofN-bromophthalimide as oxidising agent in a strong acid medium (methanol/ sulphuric acid 1 1 v/v). The produced red or violet color possesses absorption maximum range from 500 to 530 nm. A linear relationship exists between the absorbance at (max) and concentration in the range 5 to 40 g ml–1 with apparent molar absorptivities range from 6 × 103 to 12 × 1031 mol–1 cm–1. The color is developed instantaneously for all the studied phenothiazines except for thioproperazine mesylate, trifluoperazine dihydrochloride and prochlorperazine mesylate that require 25, 15 and 25 min, respectively, for complete reaction. The developed colors are stable over 24 h. The average % recovery is 99.85±0.61 to 100.28±0.95. The method was applied successfully to the microdetermination of chlorpromazine HCl, promethazine HCl, pericyazine, thioproperazine mesylate, perphenazine, prochlorperazine mesylate, trimeprazine tartrate and trifluoperazine 2HCl either in pure form or incorporated in their pharmaceutical preparations. The results of analysis are in good agreement with those of the official B.P. 1988 and USP XXII. 相似文献
6.
Reaction of benzyloxycarbonyl-5-oxazolidinones and of N-benzyloxycarbonylamino acids with BCl3 in dichloromethane at room temperature affords the corresponding free amino acids. 相似文献
7.
Shtamburg V. G. Klots E. A. Pleshkova A. P. Avramenko V. I. Ivonin S. P. Tsygankov A. V. Kostyanovsky R. G. 《Russian Chemical Bulletin》2003,52(10):2251-2260
Procedures were developed for the synthesis of N-acyloxy-N-alkoxy derivatives of ureas, carbamates, and benzamides by the reactions of the corresponding N-alkoxy-N-chloro derivatives with sodium carboxylates in MeCN. N-Chloro-N-ethoxy-p-toluenesulfonamide was inert in this reaction. Alcoholysis of N-acyloxy-N-alkoxy derivatives of ureas, carbamates, and tert-alkylamines afforded the corresponding N,N-dialkoxy derivatives, whereas alcoholysis of N-acetoxy-N-ethoxybenzamide gave rise to alkyl benzoates. 相似文献
8.
I. V. Ovchinnikov A. S. Kulikov M. A. Epishina N. N. Makhova V. A. Tartakovsky 《Russian Chemical Bulletin》2005,54(5):1346-1349
Earlier unknown N-trinitroethyl derivatives of acetylhydrazine, 4-amino-1,2,4-triazole, and 2,4,6-triamino-1,3,5-triazine, which are potential
components for gas-generating formulations, were synthesized.
Dedicated to Academician N. K. Kochetkov on the occasion of his 90th birthday.
__________
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1306–1309, May, 2005. 相似文献
9.
P. V. Arbuzov M. G. Voronkov R. G. Mirskov E. V. Bakhareva V. I. Rakhin 《Russian Chemical Bulletin》1996,45(3):720-721
The photoinduced reaction ofN-trialkylstannyl-N-triorganylsilyl-substituted allylamines with perfluorocarbonyl iodides results in the formation of 1-triorganylsilyl-2-(,a-dihydroperfluoroalkyl)aziridines.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya. No. 3, pp 759–760, March, 1996. 相似文献
10.
L. B. Kulikova G. I. Ezhova N. E. Kravchenko O. V. Dorofeeva A. S. Kulikov A. G. Zavozin 《Russian Chemical Bulletin》2007,56(8):1631-1636
Conditions for N-acylation of 2-amino-5-aryl-6H-1,3,4-thiadiazines with trifluoroacetic anhydride and halogen-substituted carboxylic acid halides with retention of the initial
heterocyclic system were found. 5-Aryl-2-haloacylamino-6H-1,3,4-thiadiazines were obtained in preparative yields. Their reactions with hetarenethiols afforded N-hetarylthioacyl derivatives.
Dedicated to Academician V. A. Tartakovsky on the occasion of his 75th birthday.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1570–1575, August, 2007. 相似文献
11.
Dodonov V. A. Zaburdaeva E. A. Stepovik L. P. Cherkasov V. K. 《Russian Chemical Bulletin》2003,52(4):910-915
The tri-tert-butoxyaluminum—tert-butyl hydroperoxide system generates molecular oxygen in the electron-excited singlet state (1O2), which oxidizes diphenylamine, N-ethylaniline, aniline, and 2,6-diisopropylaniline to form nitroxyl radicals. The latters were identified by ESR at 240—293 K. Oxidation proceeds via the intermediate formation of nitrogen-containing N-peroxide compounds. 相似文献
12.
Derek G. Leaist 《Journal of solution chemistry》1989,18(5):421-435
Ternary diffusion coefficients have been measured conductimetrically for polyacrylic acid (90,000 g-mol–1) + polyacrylic acid (5,000 g-mol–1) + water at 25°C. Binary diffusion coefficients for each fraction of polyacrylic acid have also been measured. The conductimetric results support previously reported Gouy optical data that indicated strong coupling between the diffusing polyacrylic acids. Although the carboxylic groups are only weakly ionized (pKa 4.3), each polyacrylate anion carries a substantial electric charge due to the large number of carboxylic groups per polyion. An approximate analysis suggests that the electric field generated by diffusion of the polyacrylate ions with hydrogen counterions is responsible for the strongly coupled diffusion. The theory provides an explanation for the previously reported experimental results that indicate heavier fractions of polyacrylic acid can diffuse more rapidly than lighter fractions. To help interpret the polyacrylic acid data, ternary diffusion coefficients have also been measured for n-butyric acid + acetic acid + water. The diffusion of the monocarboxylic acids is weakly coupled. 相似文献
13.
Electrochemical methoxylation of substituted 4H-imidazole 1,3-dioxides has been carried out for the first time. Nitroxyl radicals of the 2- and 3-imidazoline series with methoxy groups at the -carbon atom of the radical site were synthesized. The yields and ratios of the electrochemical methoxylation products are close to those observed in the chemical methoxylation carried out with PbO2 and MnO2 as oxidants.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp.469–471, March, 1994. 相似文献
14.
2,2-Dimethyl-3-(2-methyl-3-indolyl)cyclopropylacetic acid, its amide and esters, and the corresponding alcohol, viz., the product of ester reduction by LiAlH4, were synthesized. The chemoselectivity of N- and O-alkylation of these compounds was studied. Selective monoalkylation at the nitrogen atom of the heterocycle, O-alkylation to the side chain, or dialkylation at both nucleophilic sites can be carried out under conditions of phase-transfer catalysis. The N-acylation at the indole fragment of nitrile of this acid occurs only under the Vilsmeier—Haak formylation conditions. 相似文献
15.
Pankrushina N. A. Nikitina I. A. Anferova N. V. Osadchii S. A. Shakirov M. M. Shults E. E. Tolstikov G. A. 《Russian Chemical Bulletin》2003,52(11):2490-2499
Efficient procedures were developed for N-deethylation of lappaconitine to give N(20)-deethyllappaconitine. Alkyl derivatives of N(20)-deethyllappaconitine, including labeled lappaconitine, and N(20)-acetoxy-N(20)-deethyllappaconitine were prepared for the first time. The assignments of the signals for the carbon atoms in the 13C NMR spectra of lappaconitine and related lappaconine were refined using 13C—13C 2D INADEQUATE and 2D 13C—1H correlation experiments. 相似文献
16.
N. V. Kolotova V. O. Koz'minykh E. V. Dolbilkina E. N. Koz'minykh 《Russian Chemical Bulletin》1998,47(11):2246-2248
Aroylpyruvic acids and their methyl esters react witho-aminophenyldiphenylmethanol to form 4-aryl-2-[2-(1-hydroxydiphenylmethyl)phenylamino]-4-oxobut-2-enoic acids and their esters.
The α-enamino acids obtained undergo intramolecular heterocyclization in the presence of Ac2O to affort substituted 4,5-dihydrobenzo[e][1,4]oxazepin-3(1H)-ones. The reaction of 5-arylfuran-2,3-diones witho-aminophenyldiphenylmethanol leads to products of decyclization, 2-(1-hydroxydiphenylmethyl)phenylamides of 4-aryl-2-hydroxy-4-oxobut-2-enoic
acid, which upon heating in AcOH or Ac2O yield 3-aroylacetyl-1,1-diphenyl-1H-benzo[d][1,3]oxazines.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2317–2319, November, 1998. 相似文献
17.
Infrared absorption (IR) and vibrational and electronic circular dichroism (VCD and ECD, respectively) spectra of tert-butylcarbamoylquinine (t-BuCQN) and pseudoenantiomeric tert-butylcarbamoylquinidine (t-BuCQD), denoted as selectors (SO), complexed with chiral (S) and (R)-3,5-dinitrobenzoylleucine (DNB-Leu) and achiral 3,5-dinitrobenzoylglycine (DNB-Gly), denoted as selectands (SA), in methanol
and acetonitrile, with the spectra of pure SA and SO are reported. H–D exchange of exchangeable hydrogen atoms of SA and SO
in deuterated methanol which occurs in IR and VCD experiments is exploited to identify Amide II and Amide III vibrational
modes. The formation of preferentially bound complexes composed of sterically compatible combinations of DNB-Leu and SO are
manifested by increased intensity of VCD bands assigned to vibrations of amide, carbamate, quinoline, and dissociated carboxylate
group and also by increased ECD signals. The VCD technique revealed similarities between the strongly bound diastereomeric
complex of chiral DNB-Leu and SO and the complex of achiral DNB-Gly and SO, highlighting the leading role of SO in the formation
of SA–SO complex.
Figure Vibrational circular dichroism study: Interaction markers typical of the binding between the quinine selector and the derivatized
amino acid selectand 相似文献
18.
V. A. Lopyrev L. I. Larina A. I. Albanov M. S. Sorokin G. V. Dolgushin 《Russian Chemical Bulletin》1996,45(12):2861-2862
Silylotropy in 4-substitutedN-trimethylsilypyrazoles is studied by dynamic1H,13C, and29Si NMR spectroscopy. The catalytic 1,2-migration of a trimethylsilyl group in 4-halo-N-trimethylsilylpyrazoles was detected. Silylotropy inN-trimethylsilylpyrazoles in the presence of halogens of trimethylhalosilanes is believed to proceed through formation ofN,N-bis(trimethylsilyl)pyrazolium salts, the barrier of silylotropy in pyrazoles being markedly reduced.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 3011–3013, December, 1996. 相似文献
19.
N-[1-Hydroxyimino-2-methyl-1-(2-pyridyl)prop-2-yl]hydroxylamine, a new representative of the series of α-hydroxylamino oximes,
was synthesized. Based on this compounds, 3-imidazoline 3-oxide and 2-imidazoline 3-oxide derivatives, were obtained, and
some of their chemical properties were investigated.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 131–136, January, 1997. 相似文献
20.
Several 2,5-disubstituted oxazole-4-carboxylates were prepared in high yields from the methyl esters of N-acyl-β-halodehydroaminobutyric acid derivatives by treatment with a 2% solution of DBU in acetonitrile. The scope of this reaction was investigated and it was found that dehydrodipeptides having a β-bromodehydroaminobutyric acid residue gave the corresponding oxazoles in good yields. The photophysical properties of some of the oxazoles prepared were studied in four solvents of different polarity. All compounds have reasonable high fluorescence quantum yields and a moderate solvent sensitivity, which makes them good candidates to be used as fluorescent probes. One of the fluorescent oxazoles prepared was inserted after cleavage of the methyl ester into two model peptides using a conventional solution phase strategy. The photophysical properties of the labelled peptides were studied in ethanol and water and compared with those of the oxazole. The results obtained showed that the oxazole maintains a good fluorescence level and the same solvent sensitivity when linked to a peptide chain. 相似文献