Investigations in the imidazole series

Imidazo[1,2-a]imidazole derivatives were synthesized by the reaction of 1-acylmethyl-2-bromo-4,5-diphenylimidazoles with ammonia and primary amines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1243–1247, September, 1971.     

Synthesis and properties of oxazolo[3,2-f]xanthines

Oxazolo[3,2-f]xanthines were synthesized by the reaction of 7-acylalkyl-8-bromo-3-methyl- and -1,3-dimethylxanthines with sodium benzoate in dimethylformamide. Their alkylation with methyl iodine was studied. The reaction of oxazolo[3,2-f]xanthines with primary amines leads to the previously described imidazo[1,2-f]xanthines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 534–537, April, 1988.     

Synthesis,properties, and mass-spectrometric behavior of 6-substituted imidazo[1,2-f]xanthines

Alkylation at the N₍₆₎ atom of 6H-1-ethyl ethyl(methyl-2-phenylimidazo[1,2-f]xanthenes was realized with -halogenoacetic esters. The alkylation of these compounds with glycidyl alcohol in the presence of organic bases also leads to 6-(dihydroxypropyl) derivatives.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1105–1109, August, 1987.     

Direct problem for a nonlinear evolutionary system

In this article, we consider the first initial boundary-value problem for an evolutionary system describing nonlinear interactions of electromagnetic and elastic waves. The system under study consists of three coupled differential equations, one of them is a hyperbolic equation (an analogue of the Lamé equations) and the other two equations form a parabolic system (an analogue of the diffusion Maxwell system). Existence and uniqueness results are established. We also prove the stability estimate of a weak solution.     

Vibrations of flexible cylindrically anisotropic annular plates

We study the problem of bending vibrations of a prestressed flexible annular plate made of a cylindrically anisotropic material. The problem is solved using the method of initial functions and the theory of multiplicative integration. Using the resulting computational formulas we analyze the critical values of the loading parameters of the plate by the dynamic criterion. One table. Bibliography: 2 titles. Translated fromTeoreticheskaya i Prikladnaya Mekhanika, No. 28, 1998, pp. 92–97.     

Investigations in the xanthine series and among its condensed derivatives

A method has been developed for obtaining derivatives of 8-methyl-2,3-dihydro-6H-imidazo[1,2-f]xanthine. It has been established that 2,3-dihydroimidazo[1,2-f]-xanthines alkylate in position 6 of the uracil fragment. A method has been developed for obtaining derivatives of 2,3-dihydroimidazo[1,2-f]purin-7-one. The structure of the compounds synthesized have been confirmed by IR and PMR spectroscopy. Zaporozh'e Medical Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 623–626, September–October, 1980.     

The first initial–boundary-value problem for a nonlinear model of the electrodynamics of vibrating elastic media

The first initial–boundary-value problem for nonlinear differential equations describing the interactions of a vibrating electroconductive body and the electromagnetic field is studied. We assume that the motion of the body occurs at velocities that are much smaller than the velocity of propagation of the electromagnetic waves through the elastic medium. The model under study consists of two coupled differential equations; one of them is the hyperbolic equation (an analogue of the Lamé system) and the other is the parabolic equation (an analogue of the diffusion Maxwell system). We prove an existence and uniqueness result. The proof is based on the classical Faedo–Galerkin method.     

Synthesis,physicochemical properties,and mass spectrometric study of some 8-methyl-6H-thiazolo[3,2-f]xanthines

Alkylation of 8-mercapto-3-methylxanthine with -haloketones has given the corresponding aroylmethylthio-3-methylxanthines, from which have been obtained some novel 3-aryl-8-methyl-6H-thiazolo[3,2-f]xanthines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1534–1539, November, 1987.