2-Carbomethoxyaminobenzimidazole in the synthesis of 2-oxo-1,2,3,4-tetrahydropyrimido-[1,2-a]benzimidazole and its derivatives

A one-step method was developed for the preparation of 2-oxo-1,2,3,4-tetrahydropyrimido[1,2-a]benzimidazole and its 3-methyl, 4-methyl, 4,4-dimethyl, and 4-phenyl derivatives by heating 2-carbomethoxyaminobenzimidazole with acrylic, methacrylic, crotonic, and cinnamic acids at 140–200°C. A possible scheme for the formation of the indicated compounds is presented.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1389–1393, October, 1977.     

Inelastic deformation of flexible cylindrical shells with an elliptic hole

The elastoplastic state of isotropic homogeneous cylindrical shells with elliptic holes and finite deflections under internal pressure is studied. Problems are formulated and numerically solved taking into account physical and geometrical nonlinearities. The distribution of stresses (displacements, strains) along the boundary of the hole and in the zone of their concentration is analyzed. The data obtained are compared with the numerical solutions of the physically nonlinear, geometrically nonlinear, and linear problems. The stress-strain state of cylindrical shells in the neighborhood of the elliptic hole is analyzed with allowance for nonlinear factors __________ Translated from Prikladnaya Mekhanika, Vol. 43, No. 5, pp. 46–54, May 2007.     

Bisquaternary salts of alkaloids of the heliotridane series and some products of their transformation

Summary The reaction of ,-dibromoalkanes with trachelanthimidine and its derivatives and of bis (4-chlorobutyl) ether with the alkaloids lindelofine and viridiflorine have yielded bisquaternary salts of the pyrrolizidine series.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 368–371, May–June, 1977.