Influence of high-order dispersion on self-focusing. II. Numerical investigation

The self-focusing described by the nonlinear Schrödinger equation with a higher-order derivative term is investigated numerically. We demonstrate that, depending on the sign before this term, it may lead in the final stage either to defocusing or to a steady homogeneous wave beam. In both cases the transition to the final state is shown to be oscillatory.     

Benzindoles. 23. 2-formyl- and 3-formyl-4,5-benzindoles

It is shown that, in addition to the usually formed 3-formyl-4,5-benzindole, 2-formyl-4,5-benzindole can be obtained via the Vilsmeier reaction. The IR, PMR, and UV spectra of the 2- and 3-formyl isomers are compared, and their possible conformations are discussed.See [1] for Communication 22.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 343–345, March, 1984.     

Benzindoles

A large amount of structural similarity between 4,5-benzindole and naphthalene and between 6,7-benzindole and indole was detected on a basis of a comparison of the absorption, fluorescence, and phosphorescence spectra of isomeric benzindoles with the spectra of indole and naphthalene. A great analogy between indole and 6,7-benzindole as compared with 4,5-benzindole is also observed during the formation of hydrogen bonds, as indicated by the shift in the absorption band of the NH group in the IR spectra of the investigated compounds in the presence of various proton acceptors.     

Benzindoles. 21. Nitration of 3-formyl[4, 5]-and 3-formyl [6,7] benzindoles

It was established that products of monosubstitution of 4-nitro- and 7-nitro-3-formyl[4,5] benzindoles and products of disubstitution of 4,8-dinitro- and 7,8-dinitro-3-formyl [4,5] benzindoles are formed in low yields in the nitration of 3-formyl [4,5]benzindole with sodium nitrate in concentrated sulfuric acid. Similar nitration of 3-formyl [6,7] benzindole leads to 9-nitro- and 5, 6-dinitro-3-formyl [6,7]benzindoles. The 3-formylnitrobenzindoles obtained were converted to nitrovinyl derivatives by condensation with nitromethane.See [1] for Communication [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 949–955, July, 1980.     

Benzindoles

The previously undescribed tetrahydro[4, 5]- and tetrahydro[6, 7]benzindoles and some of their derivatives were synthesized by Fischer cyclization of pyruvic acid 5- and 6-tetralinylhydrazones. A linear isomer — tetrahydro[5, 6]benzindole^–and its derivatives were obtained only in a mixture with tetrahydro[4, 5]-benzindole. The geometrical isomers of the pyruvic acid hydrazones were isolated and characterized. A method for the separation of the mixtures of 5- and 6-aminotetralins was developed. The structures of the isolated compounds were confirmed by the PMR and IR spectral data.See [1] for communication XIII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 634–640, May, 1978.     

Resonant control of solitons

It is shown that the effect of “scattering on resonance” can be used to control envelope solitons in the driven nonlinear Schrödinger equation. The control occurs by the frequency modulated driving with multiple crossing of the resonant frequency of the soliton.     

Benzindoles

The behavior of tetrahydro[4,5]- and tetrahydro[6,7]benzinodoles in the Vilsmeier reaction was investigated. It was established that the steric hindrance created by the cyclohexane ring condensed in the 4 and 5 positions has a substantial effect on the character of the reaction of tetrahydrobenzindoles with various N,N-disubstituted amines. A case of N-acylation in the investigated reactions is described. 3-Formyl-4,5,6,7-tetrahydro[4,5]- and 6,7,8,9-tetrahydro[6,7]-benzindoles were converted to the corresponding tryptamines.See [1] for communication 16.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 360–365, March, 1979.