Yavolovskii A. Purines, their heteroanalogs and N-oxides on the imidazole and pyrimidine derivatives. Synthesis, structure and conversions

The convenient methods of diimidazo[1,5-a;1',5'-d] pyrazine(4H,9H)-5,10-diones, derivatives of 5-(4'-R-benzoyl)-, 5-aminoimidazole-4-carboxylic acids and imidazole-4,5-dicarboxylic acid, imidazo[4,5-c]furan, xanthines with alkyl-, cycloalkyl- and aryl-sabstituents in the 1 position of the cycle, imidazo[4,5-d]pyridazines 16- and 18-membered tetraazamacroheterocycles, condensed with two imidazolic nuclei, and also of hydrazino-, hydroxylamino-, nitroso-, and isonitrosopyrimidines, isomeric N-oxides of 1,2,3-triazolo[4,5-d]pyrimidin-5,7-diones, amino-, ureido-1,2,3-triazole carboxylic acids , their amides and hydrazides, 2-oxides 1,2,5-chalcogendiazolo[3,4-d]pyrimidines, 4-oxides of 1,2,4-triazino[5,6-d]pyrimidines were developed. The found ability of crown-ethers to form crystalline complexes with mono- and bicycloderivatives of pyrimidine allows to study the peculiarities of structure of the later by X-ray diffraction analysis method.