One-pot preparation of derivatives of the unknown 1,9-diazaphenalene ring by a consecutive electrocyclic ring-closure/Claisen rearrangement/intramolecular amination process

Abstract
A short synthesis of 1,9-diazaphenalene derivatives (8) based on a new method of two consecutive pyridine annelations which involves cyclization of conjugated carbodiimides (5) is described.