Studies on the Reactions of Cyclic Oxalyl Compounds: Synthesis and Thermolysis of 2,3-Dihydro-4-(4-methylbenzoyl)-5-(4-methylphenyl)-furan-2,3-dione and its N-Reaction with Nucleophiles

Oxalyl chloride combines with 1,3-bis(4-methylphenyl) propane-1,3-dione to afford novel titled compound furan-2,3-dione 1, whose synthesis, X-ray structure analysis and some reaction are reported. Thermolysis is supposed to occur by the ring opening of the compound 1 followed by the intermediate diacylketene dimerization resulting in the pyran-4-one 2. The reaction of 1 with some aromatic amines and diamines led to the formation of the pyrole-2’3-dione 3,4 and the quinxalin-2-one derivative 5, respectively. Most of them were compared with their previous analogs. The structure of all products were confirmed by IR, 1H- and 13C-NMR spectroscopic measurements, in the case of 1 also by an X-rays study. 1 crystallizes in the monoclinic space group C2/c with eight molecules 1 per cell. The reaction pathways leading to the compounds 1,2 and 4 were briefly discussed.