Synthesis of imidazo[4,5-<i>e</i>][1,3]thiazino[2,3-<i>c</i>][1,2,4]triazines via a base-induced rearrangement of functionalized imidazo[4,5-<i>e</i>]thiazolo[2,3-<i>c</i>][1,2,4]triazines
Dmitry B. Vinogradov, Alexei N. Izmest’ev, Ангелина Н. Кравченко, Yuri A. Strelenko, Галина А. Газиева
Abstract
A series of imidazo[4,5- e ][1,3]thiazino[2,3- c ][1,2,4]triazines was synthesized via a cascade sequence of hydrolysis and skeletal rearrangement of imidazo[4,5- e ]thiazolo[2,3- c ][1,2,4]triazin-7(8 H )-ylidene)acetic acid esters in methanol upon treatment with excess KOH. Imidazo[4,5- e ]thiazolo[3,2- b ][1,2,4]triazin-6(7 H )-ylidene)acetic acid esters are also suitable substrates for the reaction. In this case hydrolysis and thiazole ring expansion were accompanied with the change of the thiazolotriazine junction type from thiazolo[3,2- b ][1,2,4]triazine to thiazino[2,3- c ][1,2,4]triazine.
Topics & Concepts
ChemistryHydrolysisRing (chemistry)ThiazoleAcetic acidTriazineMethanolStereochemistryMedicinal chemistryOrganic chemistrySynthesis and Characterization of Heterocyclic CompoundsSynthesis and Reactivity of HeterocyclesSynthesis and Biological Evaluation