DIMROTH REARRANGEMENT IN THE SYNTHESIS OF SUBSTITUTED CYCLOPENTA- AND CYCLOHEXA[4,5]THIENO[2',3':4,5]PYRIMIDO[1,6-<i>b</i>][1,2,4]TRIAZINES
DOI:
https://doi.org/10.1007/3232Keywords:
2, 4-diketoesters, thieno[2, 3-d]pyrimidines, thieno[2', 3', 4, 5]pyrimido[1, 6-b][1, 4]triazines, Dimroth reaction mechanism, heterocyclizationAbstract
A simple and effective method has been developed for the synthesis of previously unknown cyclopenta- and cyclohexa[4',5']thieno-[2',3':4,5]pyrimido[1,6-b][1,2,4]triazines in a single step by reaction of 4-hydrazinocyclopenta- and 4-hydrazinocyclohexa[4,5]thieno[2,3-d]pyrimidines with sodium salts of methyl 4-aryl(heteryl)-2,4-dioxobutanoates. It was shown that the determining factor in the formation of tetracyclic products was isomerization by intramolecular recyclization with mechanism analogous to the Dimroth rearrangement.
Authors: Dmitriy O. Kolomeitsev, Viktor I. Markov, Svetlana A. Varenichenko*, Valeriya O. Astakhina,
Sergiy I. Kovalenko, Olexander V. Kharchenko, Aleksandr V. Mazepa