Pyrimidine derivatives. 58. A new method for synthesizing 7-aminopyrrolo[2,3-d]-pyrimidine derivatives

A number of aldimines of 7-aminopyrrolo[2,3-d]pyrimidine have been synthesized by the action of bromine on hydrazones of 5-allyl-4-hydrazinopyridine. The structures of the compounds obtained were confirmed by IR spectroscopy and mass spectrometry.For Communication 57, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 678–681, May, 1985.     

Synthesis and thermal decomposition of haloalkoxy-sym-triazines. 7. Thermal decomposition of 2-dialkylamino-4-(2-chloroethoxy)-6-methoxyamino-sym-triazines

Two 2-dialkylamino-4-(2-chloroethoxy)-6-methoxyamino-sym-triazines were synthesized. It was established that when they are heated at 120° C, the 2-chloroethoxy group undergoes rearrangement with cyclization to give 2-dialkylamino-4-oxo-8-methoxy-6, 7-dihydroimidazo [1,2-a]-sym-triazines, the structure of which was confirmed by data from the IR, PMR, and mass spectra.See [6] for Communication 6.Translated from Khimiya Geterotsilicheskikh Soedinenii, No. 8, pp. 1122–1124, August, 1981.     

Synthesis and thermal decomposition of haloalkoxy-sym-triazines. 8. Synthesis and thermal decomposition of 2-methoxy(methylthio)-4-(2-chloroethylthio)-6-dialkylamino-sym-triazines

New 2-chloroethylthio derivatives of sym-triazine were obtained by the reaction of mercapto-sym-triazines and dichloroethane. It was established that these chlorides undergo cyclization to give 2-dialkylamino-4-oxo(thioxo)-4,5,6,7-tetrahydrothiazolo [1,2-a]-sym-triazines, the structure of which was confirmed by PMR and mass-spectral data, at moderate temperatures.See [7] for Communication 7.Translated f rom Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1275–1278, September, 1981.     

Mass-spectrometric behavior of some cyano-substituted 4-(β-chloroethylmercapto)-sym-triazines

Intense [M-Cl]⁺ and [M-CT₂=CCNCl]⁺ ion peaks are characteristic for the mass spectra of 4-(-chloro--cyanoethylmercapto)-sym-triazines. The introduction of monoalkylamino groups into the 2 and 6 positions of the heteroring does not lead to the development of [M-HCl]⁺ ion peaks in the mass spectra or to a change in the characteristic fragmentation pathways.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1268–1270, September, 1982.     

The mechanism of interaction between molybdogermanic acid and the basic dye Crystal Violet

On the basis of light-absorption studies on solutions of Crystal Violet (CV) molybdogermanate in acetone, the optimal pH conditions for quantitative formation of molybdogermanic acid (MGA) have been determined. Di, tri-, and tetra-salts of MGA have been formed and isolated. It has been shown that formation of the higher salts is favoured by lowering the acidity, but this increases also the amount of the solid co-product CV—isopolymolybdate. To overcome this inconvenience the surplus molybdate ions are masked by adding oxalate ions, thus allowing the separation of the corresponding solid tetra-salt up to pH = 6.5; the molar absorptivity of this compound in acetone solution is very high (4.2 × 10⁵ 1.mole⁻¹.cm⁻¹).     

Study of optical narrow-band N-resonance formed in the vapor of isotope 87Rb atoms in an external magnetic field

Narrow-band cascade N-resonance formed in a Λ-system of rubidium atoms was investigated. Radiation of two continuous narrow-band lasers was used, one of which had a fixed frequency, while the second one was a probe laser. N-resonance may have a sub-natural width and exhibits enhancement of absorption. The behavior of N-resonance in an external magnetic field was examined with use of ⁸⁷Rb atomic vapors.     

X-ray diffraction in AT-cut quartz single crystal at acoustic excitation at the fundamental frequency

X-ray diffraction on different atomic planes of an AT-cut quartz crystal is studied experimentally in the Laue geometry in case of excitation by acoustic waves at the first resonant (fundamental) frequency. Acoustic waves lead to an increase in the integral intensity of the reflection-diffracted beam. The amplification coefficients in reflection are measured in dependence on the amplitude of a.c. voltage applied to the crystal at the resonant frequency. The frontal distributions of the intensity of the beam diffracted in the reflection direction are obtained for different atomic planes.     

High contrast <Emphasis Type="Italic">D</Emphasis><Subscript>1</Subscript> line electromagnetically induced transparency in nanometric-thin rubidium vapor cell

The electromagnetically induced transparency (EIT) on the atomic D ₁ line of rubidium is studied using a nanometric-thin cell with atomic vapor column length in the range of L=400–800 nm. It is shown that the reduction of the cell thickness by four orders as compared with an ordinary cm-size cell still allows to form an EIT resonance for L=λ=794 nm with the contrast of up to 40%. Further reduction of thickness to L=λ/2 leads to significant reduction of EIT contrast, verifying that the key parameter for EIT in wavelength-scale-thickness cells is not the value of L itself but L/λ ratio. Remarkable distinctions of EIT formation in nanometric-thin and ordinary cells are demonstrated. Well-resolved splitting of the EIT resonance in a magnetic field for L=λ can be used for magnetometry with nanometric spatial resolution. The presented theoretical model well describes the observed results.     

Submanifolds with commuting normal vector field

This is a survey of studies on submanifolds of spaces of constant curvature with a parallel normal vector field, parallel second or third fundamental form, or with a parallel (or satisfying other geometric conditions) field of normal p-directions, and on conformally flat submanifolds.Translated from Itogi Nauki i Tekhniki, Seriya Problemy Geometrii, Vol. 14, pp. 73–100, 1983.     

Pyrimidine derivatives. 56. New method for the synthesis of thieno[2,3-d]pyrimidine

A new scheme was developed for the synthesis of 2,4-dimethy1-5,6-dihydro-6-bromomethylthieno[2,3-d]pyrimidine by bromination of the corresponding 5-allyl-6-mercaptopyrimidine. It is shown that when the bromomethyl derivative is treated with sodium methoxide a molecule of hydrogen bromide is split out to give 2,4,6-trimethylthieno[2,3-d]pyrimidine. The structures of the synthesized compounds were proved by PMR spectroscopy and mass spectrometry.See [1] for Communication 55.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 118–120, January, 1982.