Synthesis, characterization and some reactions of novel 4-aroy1-5-ary1-2,3-dihydro-2,3-furandiones

Symmetrical diaryl β-diketones Ic,d as dibenzoylmethane derivatives were obtained from 2,3-dihalo-1 ,3-bis( 4-aryl)-I-propanone and sodium methoxide as yellow or white crystals in 22% or 51 % yield. The β-diketones Ic,d combine with oxalyl chloride to yield 4-(3,4-dimethoxy benzoyl)-5-(3 ,4-dimethoxyphenyl)furan -2,3-dione (2c) and 4-(4-methylbenzoyl)-5-(4-methylphenyl)furan-2,3-dione (2d), respectively, which are novel starting materials for synthesizing many heterocycles. Thermal decomposition of 2c,d is supposed to occur by the ring opening of compound 2 followed by dimerization of the intermediate x-oxoketene resulting in the pyran-4-ones 3c,d. Alternatively, pyran-4-ones 3c,d were obtained by thermolysis of 2c,d in xylene in presence of Ic and Id, most likely by trapping the diacylketene intermediates. All newly synthesized compounds were characterized by elemental analysis, IR, IH and I3C NMR spectral data. All were compared with their previous analogues