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71.
Bozhenkov G. V. Levkovskaya G. G. Mirskova A. N. Dolgushin G. V. Larina L. I. Ushakov P. E. 《Russian Journal of Organic Chemistry》2003,39(8):1069-1075
Reactions of 2,2-dichlorovinyl and 2,2-dibromovinyl ketones with alkylhydrazines afford respectively 1-R-3-alkyl(aryl)-5-chloro- or 5-bromopyrazoles in preparative yields. The dichloroacrolein forms with alkylhydrazines and dimethylhydrazine only the corresponding hydrazones. Quantum-chemical calculations were performed characterizing the structure of the obtained ketones and dichloroacrolein alkylhydrazones, of dichloroacrolein dimethylhydrazone, of 1-alkyl-5-chloropyrazolinium halides, and 1-alkyl-5-chloropyrazoles. 相似文献
72.
G. V. Bozhenkov V. A. Savosik L. I. Larina A. N. Mirskova G. G. Levkovskaya 《Russian Journal of Organic Chemistry》2006,42(6):901-906
The nitration of 5-chloropyrazoles with a mixture of 100% nitric acid and 65% oleum or a mixture of 60% nitric acid and polyphosphoric acid gave substituted 5-chloro-4-nitropyrazoles in 45–91% yield. The nitration of 3-aryl-5-halopyrazoles was accompanied by introduction of a nitro group into the aromatic ring. 4-Chloropyrazoles failed to undergo nitration under these conditions. The reaction of 5-chloro-1,3-dimethyl-4-nitropyrazole with ethyl cyanoacetate in DMSO in the presence of K2CO3 led to the formation of ethyl 2-cyano-2-(1,3-dimethyl-4-nitro-1H-pyrazol-5-yl)acetate. 相似文献
73.
Voronkov M. G. Trofimova O. M. Turchaninov V. K. Zel'bst E. A. Bolgova Yu. I. Belyaeva V. V. Larina L. I. Aksamentova T. N. Mikhaleva A. I. Chernov N. F. 《Russian Journal of Organic Chemistry》2003,39(10):1458-1466
Organosilicon derivatives of pyrrole, indole, carbazole, and 2-methylindole containing (MeO)3SiCH2, Et3SiCH2, or N(CH2CH2O)3SiCH2 group on the nitrogen atom were synthesized. Their structure and stereoelectronic parameters were studied by X-ray diffraction, 1H, 1
3C, 1
5N, and 2
9Si NMR, IR and UV spectroscopy, and dielcometry, as well as by quantum-chemical calculations. 相似文献
74.
The specific isobaric heat capacities of poly (methylmethacrylates) (PMMA) having various tacticities were measured by the DSC method within a broad range of temperatures including the glass transition. Glasses with uniform thermal history were used in the measurements and the data were treated by employing a procedure which provided the thermodynamic Tg independent of the experimental conditions. The semiquantitative validity of Boyer's empirical relationT
g
×cp=const. was confirmed; also it was found that within the limits of experimental accuracy the cp,g values at 298 K andC
p,l
values at 400 K are independent of the tacticity of the sample.Using the data thus measured and linearized equations representing the dependence ofT
g
on the content of iso-, syndio- and heterotriads, the Tg values of pure isotactic PMMA and pure syndiotactic PMMA were found to be respectively 315 K and 397 K.Dedicated to Professor Dr. F. H. Müller. 相似文献
75.
V. A. Lopyrev L. I. Larina I. M. Sosonkin T. I. Vakul'skaya G. L. Kalb E. F. Shibanova 《Chemistry of Heterocyclic Compounds》1985,21(6):688-692
Using a rotating platinum ring-disk electrode, the electrochemical reduction of 2-substituted 5(6)-nitrobenzimidazoles at the platinum disk in acetonitrile and the oxidation of their radical anions at the ring were studied. During the reduction molecular hydrogen forms by a bimolecular reaction of two primary radical anions. The correlating of electrochemical quantities with the I, R, and substituent constants are evidence that E
1
2/d
depends on substituent resonance and induction effects to about the same extent, whereas i
lim
d
, n, and E
1
2/r
depend predominantly on the resonance effect.For Communication 4, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 827–832, June, 1985. 相似文献
76.
V. K. Turchaninov E. A. Motvienko L. I. Larina A. M. Shulunova L. V. Baikalova V. A. Lopyrev 《Russian Chemical Bulletin》1993,42(10):1683-1689
The nature of the first two long-wave bands in the UV spectra of 2-substituted benzimidazoles has been analyzed on the basis
of photoelectron spectra (PES). Three basic types of spectroscopic situations are typical of these compounds: 1) a change
in the sequence of the occupied MO of the ground state does not influence the order of the excited energy levels; 2) when
the π-levels are in the same order, inversion of the excited states occurs; 3) reversal of the occupied π-MO of the ground
state causes the inversion of the excited states.
For communication 7 see Ref. 1.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1761–1766, October, 1993. 相似文献
77.
Keiko N. A. Kuznetsova T. A. Chuvashev Yu. A. Sherstyannikova L. V. Larina L. I. Voronkov M. G. 《Russian Journal of Organic Chemistry》2003,39(10):1393-1397
Silylation of 1,1-dialkoxy-2-propanones with trimethyl- and tert-butyldimethylsilyl chlorides and trifluoromethanesulfonates in the presence of triethylamine and/or 1,8-diazabicyclo[5.4.0]undec-7-ene in various solvents leads to 2-trialkylsiloxypropenal acetals in up to 60% yield. 相似文献
78.
T. L. Lebedeva I. I. Vointseva L. M. Gil’man P. V. Petrovskii T. A. Larina 《Russian Chemical Bulletin》1997,46(4):732-738
It was established by Fourier-transform IR and1H NMR spectroscopy that a portion of the units of poly(1,1,2- and 1,2,3-trichlorobuta-1,3-diene) chains rearrange with migration
of the allylic chlorine (1–4%) and allylic hydrogen (3–10%) under the influence of chloroform. Rearrangement with the migration
of hydrogen under the influence of CDCl3, CCl4, and THF was also observed.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 763–768, April, 1997. 相似文献
79.
80.
Phosphorylation of tertiary amines containing at least two ethyl groups at the nitrogen atom with phosphorus pentachloride was studied. New C-chlorophosphorylated enamines were characterized by NMR spectroscopy. A scheme was suggested for the phosphorylation reaction. It was found that the presence of two aryl substituents in the molecule of tertiary ethylamine deactivated the ethyl group to block phosphorylation. Phosphorylation of N,N-diethylaniline, besides phenyl-substituted phosphorus-containing enamines, also gave phosphorylated enamines chloro-substituted in the ring. Using N-ethyl-N-methylaniline as an example, a possibility of substitution for two chlorine atoms in the PCl5 molecule with alkenyl groups was demonstrated. 相似文献