Abstract: | The hydrazones derived from coumarin-6-ylhydrazine and ethyl 6-hydrazinochromone-2-carboxylate undergo facile indolization to give 3H,7H-pyrano3,2-e]indol-7-ones (IIIb-IIIg) and ethyl 9-oxo-3H,9H-pyrano3,2-e]indole-7-carboxylates (IVb-IVd), respectively, in good yields. Compounds IVb-IVd are derivatives of a new ring system. |