Studies on the Chemical Reactions of Some 3-Substituted-6,8-dimethylchromones with Nucleophilic Reagents

A variety of 3-substituted-6,8-dimethylchromones have been synthesized and characterized. The chemical reactivity of 3-substituted-6,8-dimethylchromones was studied towards some nucleophiles, namely, S-benzyldithiocarbazate, o-phenylenediamine, and cyanoacetamide, and a diversity of products were efficiently synthesized. Reactions of 3-substituted-6,8-dimethylchromones (except 3-formyl-6,8-dimethylchromone), with nucleophilic reagents, usually proceed through nucleophilic attack at C-2 position followed by different types of heterocyclization depending on the functional group present at C-3 position. Structures of the newly synthesized products have been established based on elemental analysis and spectral data.