194546-83-3Relevant academic research and scientific papers
An efficient synthesis for pyrimido[4′,5′:4,5]-thieno[2,3-c]pyridazine derivatives via intramolecular AZA-wittig reaction-heterocyclization strategy
Quintela, José M.,Alvarez-Sarandés, Rafael,Veiga, M. Carmen,Peinador, Carlos
, p. 1319 - 1336 (2007/10/03)
A ready one-pot preparation for substituted pyrimidothienopyridazines is reported. Aza-Wittig reaction of iminophosphorane (3), derived from ethyl 5-amino-3,4-diphenylthieno[2,3-c]pyridazine-6-carboxylate (2), with isocyanates, followed by heterocyclization on addition of amines provided a novel synthetic route to the functionalized pyrimido[4′,5′:4,5]thieno[2,3-c]pyridazines (6). The guanidine-type intermediate compounds (5) derived from addition of amines to the carbodiimides (4) could be isolated and characterized, thus confirming the suggest reaction pathway.
