Synthesis of New 5-Aryl Pyrido [3', 2': 4, 5] Thieno [2, 3-e] [1, 2, 3, 4] Tetrazolo [1, 5-c] Pyrimidine Derivatives

摘要

The synthesis of new 5-arylpyrido [3', 2': 4, 5] thieno [2, 3-e][1, 2, 3, 4] tetrazolo[1, 5-c] pyrimidine derivatives is described. Few pyrido [3', 2': 4, 5] thieno [2, 3-e][1, 2, 3, 4] tetrazolo [1, 5-c] pyrimidines are known but, to the best of our knowledge, none of their 5-aryl derivatives has been reported in the literature. The routes to these compounds are limited and start from suitably substituted pyridothienopyrimidines either through diazotization of their hydrazino derivative with sodium nitrite in acetic acid or by the reaction of their chloro compound with sodium azide in ethanol or acetonitrile. In connection with our interest in the chemistry of fused thienopyridines, we reported a convenient synthesis of pyrido [3', 2': 4, 5] thieno [3, 2-d] pyrimidine-4(3H)-ones from ethyl-3-amino [2, 3-6] pyridine-2 carboxylate through heterocyclization with aryl nitriles. In continuation of this work and due to our interest in the synthesis of fused heterocycles we report herein a facile one-step synthesis of new 5-arylpyridothieno tetrazolopyrimidine derivatives (2a-f).