A thermally initiated intramolecular criss-cross cycloaddition of 3-substituted symmetrical homoallenyl azines (5) was searched. Their cyclization led to interesting new fused heterocyclic systems consisting of four five-membered rings with two nitrogen heteroatoms (6). The preparation of azines was based on application of homoallenylaldehydes (4) in reaction with hydrazine. The homoallenylaldehydes