The behaviour of [1] benzopyrano [4, 3-c][1, 5] benzodiazepin-7 (8H)-ones 1a-c towards some N-binucleophiles have been studied. With non-aromatic hydrazines the reaction carried out in acidic medium led exclusively to the unexpected [1] benzopyrano [4, 3-c] pyrazol-4-ones 4 and 5. Compounds 1 reacted under less drastic conditions with variously substituted amidines and guanidines to give 5H-[1] benzopyrano [4, 3-d] pyrimidin-5-ones ...