Synthesis and reactions of indeno[1,2-c]chromene-6,11-dione derivatives

Abstract

Indeno[1,2-c]chromene-6,11-dione was prepared using the readily obtainable starting materials via the condensation of dimethyl homophthalate with 2,6-dichlorobenzaldehyde in the presence of sodium hydride in dry benzene followed by saponification and cyclisation with concentrated sulfuric acid at 0°C. The tendency of indeno[1,2-c]chromene-6,11-dione for undergoing nucleophilic addition has been tested by reaction with nitrogen nucleophiles such as hydrazine hydrate, hydroxylamine hydrochloride, ethyl carbazate, cyanoacetic acid hydrazide, thiosemicarbazide and 4-methylbenzenesulfonohydrazide. The IR, 1H NMR, 13C NMR and mass spectra of the synthesised compounds are discussed.