4-(4-methylbenzoyl)-5-(4-methylphenyl)furan-2,3-dione: Synthesis, thermolysis and reactions with aromatic amines and diamines

The 1,3-dicarbonyl compounds, e.g., p,p'-dimethyldibenzoylmethane (1) combines with oxalyl chloride to yield 4-(4-methylbenzoyl)-5-(4-methylphenyl)furan-2,3-dione (2) which is a novel starting material for synthesizing many heterocyclic compounds. Thermal decomposition of 2 is supposed to occur by the ring opening of the compound 2 followed by the intermediate diacylketene dimerization resulting in the pyran-4-one (3). The reactions of 2 with (alpha-naphthylamine, aniline, p-toluidine,. o-toluidine or o-phenylenediamine derivatives in benzene at the room temperature led to the formation of the 2-oxo-3-butenoic acid derivative (4), the pyrrol-2,3-dione (5), the pyrrole-2-ones (6), and the quinoxaline-2-ones (7) derivatives, respectively. All new synthesized compounds were characterized by elemental analysis, IR, H-1 and C-13 NMR spectral data. Most of them were compared with their previous analogues