INFLUENCE DE LA NATURE DES SUBSTITUANTS DANS LES REACTIONS D'EXTRUSION DE SOUFRE LORS DE L'ELABORATION DE LA CHARPENTE PYRIDO[2,3-<i>b</i>[1,4]THIAZEPINE
A strategy involving the reaction between an azaallylic anion linked to a chloropyridine and different O-ethyl thiocarboxylates has shown to be effective for the synthesis of 2-aryl and 2-heteroarylpyrido[2,3-b][1,4]thiazepine However the presence of a saturated cycle fused with the thiazepine ring results in distorsion of the parent molecule, thus weakening the conjugation, and consequently induces the sulfur extrusion from the preliminary formed cycloadduct giving rise finally to 1,5-naphthyridines.