2-Bromomethyl derivatives of benzofuran and indole and their reactions with some nucleophilic reagents

The corresponding 2-bromomethyl derivatives of benzofuran and indole were obtained by bromination of 2-methyl-3-carbethoxy-5-methoxybenzofuran and 1,2-dimethyl-3-earbethoxy-5-methoxyindole with N-bromosuccinimide. A number of alkyl(aryl)thiomethyl and dialkylaminomethyl derivatives were obtained by reaction of the 2-bromomethyl derivatives with nucleophilic reagents.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 308–311, March, 1973.     

Investigation of the structure of 2h,6h-2,6-dimethyl-4-amino-1,3,5-dithiazine by IR spectroscopy

It was established by IR spectroscopy that 2H,6H-2,6-dimethyl-4-amino-1,3,5-di-thiazine exists in the amino form in carbon tetrachloride at low concentrations.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1050–1053, August, 1981.     

1H and 13C NMR spectra of new 2-thiabicyclo[3.2.0]hept-3-enes

Three new compounds, one with the molecular formula C₆H₈S and two corresponding to C₇H₁₀S have been isolated together with the main product, divinyl sulphide, from the reaction products of acetylene with sodium sulphide. Structure determination through ¹H and ¹³C NMR with selective ¹³C? {¹H} decoupling, showed C₆H₈S to be a new heterocyclic compound, 2-thiabicyclo[3.2.0]hept-3-ene, and the two C₇H₁₀S compounds its exo- and endo-6-methyl derivatives. Since the spectral parameters of these heterocycles were not known, all possible structures corresponding to the molecular formulae were considered.     

Bistable dependence of the efficiency of second harmonic generation on the total energy of femtosecond soliton pulses propagating in an optical fiber

Taking into account the effect of cubic nonlinearity on the process of second harmonic generation by soliton-like femtosecond pulses results in a hysteresis dependence of the generation efficiency, the pulse durations, and the mismatch of the wave numbers of the interacting waves on their total energy. Color solitons with earlier unknown shapes are formed at a high efficiency of the frequency conversion. Varying the phase mismatch makes it possible to “switch” the soliton duration and the conversion efficiency without a change in the total energy of the waves or the soliton shape. It is emphasized that the soliton corresponding to the middle branch of the hysteresis dependence is stable against small perturbations. It is significant that the soliton shape remains unchanged in the considered range of energies.     

Noncatalytic hydrophosphorylation and hydrothiophosphorylation of hydroxyaldehydes

Nucleophilic addition of secondary phosphone oxides and phosphine sulfides to 2-hydroxyacet-, 2-hydroxybenz-, and 3,4-dihydroxybenzaldehydes proceeds under mild conditions (48–50°C, THF) and allows tertiary phosphine oxides and phosphine sulfides with several hydroxyl groups to be prepared.     

Selective hydrogenation of the vinyl group of 1-vinylpyrroles

The hydrogenation of 1-vinylpyrroles over Raney nickel in ethanol at 50–90°C proceeds exclusively at the 1-vinyl group and leads to the formation of 1-ethylpyrroles in 80–90% yields. The IR and PMR spectra are presented.Translated from Khimiya Geterotsilicheskikh Soedinenii, No. 2, pp. 215–216, February, 1077.     

The radiation yields of radicals in solid organic substances containing heteroatoms

EPR has been used to measure the radiation yields of radicals (G_R) in various classes of organic compounds containing heteroatoms: dialkyl disulfides, diphenyl- and dibenzyl disulfide, alkyl derivatives of thiophene, thiophenecarboxylic acids, halogen derivatives of thiophene, and saturated heterocyclic compounds containing nitrogen, oxygen, and sulfur atoms. It has been shown that 1) G_R=0.2–1 per 100 eV in saturated disulfides and cyclic sulfides, while G_R=3–8 per 100 eV in the corresponding hydrocarbons, alcohols, oxides, and alkyleneimines; 2) the introduction of a sulfur atom into aromatic compounds does not alter the radiation stability; 3) disturbance of the conjugation of halogen atoms and of the carboxyl group with the thiophene ring leads to a decrease in the radiation stability. It is suggested that the increased stability of sulfur-containing compounds may be due to the excitation of the electrons in the S atom at the d-orbitals, which lie appreciably lower in the sulfur atom than in the atoms of oxygen, nitrogen, and carbon, and the subsequent dissipation of the excitation energy.