C 98 Cyclization of N-alkylazinium cations with bifunctional nucleophiles. 15. Isomerization of thiazolo[4,5-b]quinoxalines in the presence of acids [Electronic resource] / V. N. Charushin, V. G. Baklykov, O. N. Chupakhin, V. N. Drozd // Chemistry of Heterocyclic Compounds. - 1985. - Vol. 21, № 3. - С. 331-338. - Bibliogr. : p. 337-338 (21 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): ISOMERIZATION -- CHLOROFORM -- QUINOXALINIUM CATION Аннотация: 4-Alkyl-2-phenyl-3a,4,9,9a-tetrahydrothiazolo[4,5-b]quinoxalines undergo isomerization in chloroform in the presence of acids to the regioisomeric (with respect to them) 9-alkyl-substituted derivatives. Under the same conditions 2,4-dimethyl-3a,4-9,9a-tetrahydrothiazolo [4,5-b]quinoxaline undergoes isomerization to 4-methyl-1H-2,3,3a,4,9,9a-hexahydropyrrolo[2,3-b]quinoxaline-2-thione. It was demonstrated by means of deuterium labels that in both cases the isomerization proceeds through a step involving dissociation to a quinoxalinium cation and the corresponding thioamide \\\\expert2\\nbo\\Chemistry of Heterocyclic Compounds\\1985, v.21, N 3, p. 331.pdf |