Novel ring transformations of condensed [1,2,4]triazolo-[4,3-b]pyridazine-6(5H)-one-3(2H)-thiones effected by dialkyl-acetylenedicarboxylates

Authors
Simo, M Csampai, A Harmat, V Barabas, O Magyarfalvy, G
Citation
M. Simo et al., Novel ring transformations of condensed [1,2,4]triazolo-[4,3-b]pyridazine-6(5H)-one-3(2H)-thiones effected by dialkyl-acetylenedicarboxylates, TETRAHEDRON, 57(33), 2001, pp. 7191-7198
Citations number
13
Categorie Soggetti
Chemistry & Analysis","Organic Chemistry/Polymer Science
Journal title
TETRAHEDRON
ISSN journal
00404020 → ACNP
Volume
57
Issue
33
Year of publication
2001
Pages
7191 - 7198
Database
ISI
SICI code
0040-4020(20010813)57:33<7191:NRTOC[>2.0.ZU;2-Y
Abstract
On heating with dialkyl-acetylenedicarboxylates in DMF condensed [1,2,4]-tr iazolo[4,3-b] pyridazine-6(5H)-one-3(2H)-thiones undergo unprecedented ring transformations yielding novel tetracyclic 1,3-diazepines and thiazolotria zole derivatives depending on the applied reaction temperature. The observe d substrate selectivity was interpreted on the basis of the results of comp arative theoretical calculations carried out at semiempirical level (AMI). (C) 2001 Elsevier Science Ltd. All rights reserved.