C 98 Cyclization of N-alkylammonium cations with bifunctional nucleophiles. 17. Annelation of imidazole and 1,2,4-triazine rings with pyrazines via the reactions of thiosemicarbazides with pyrazinium salts [Electronic resource] / V. G. Baklykov, V. N. Charushin, O. N. Chupakhin, N. N. Sorokin // Chemistry of Heterocyclic Compounds. - 1985. - Vol. 21, № 7. - С. 798-804. - Bibliogr. : p. Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): 1,4-DISUBSTITUTED THIOSEMICARBAZIES -- CYCLIZATION REACTIONS -- THIOSEMICARBAZIDES Аннотация: 1- and 4-mono- as well as 1,4-disubstituted thiosemicarbazies undergo cyclization reactions upon treatment with N-alkylpyrazinium and quinoxalinium salts to give N-aminosubstituted imidazo[4,5-b]pyrazines and imidazo[4,5-b]quinoxalines, respectively. Thiosemicarbazides containing substituents in the 2-position react with N-alkylquinoxaline salts to give 1,2,4-triazino[5,6-b]quinoxalines after cyclization. \\\\expert2\\nbo\\Chemistry of Heterocyclic Compounds\\1985, v.21, N 7, p. 798.pdf |