Synthesis of dialkyl 4-ethoxy-2,5-dihydro-1-(9,10-dihydro-9,10-dioxoanthracen-6-yl)-5-oxo-1H-pyrrole-2, 3-dicarboxylates

The reaction of dialkyl acetylenedicarboxylate with ethyl (9, 10-dihydro-9, 10-dioxoanthracen-6-ylcarbamoyl) formate in the presence of Ph3P produces dialkyl 4-ethoxy-2, 5-dihydro-1-(9, 10-dihydro-9, 10-dioxoanthracen-6-yl)-5-oxo-1H-pyrrole-2, 3-dicarboxylate in fairly good yields. The structures of these products were deduced from their mass, ¹H NMR, ¹³C NMR and FT-IR spectral data. Various features of this reaction will be presented and discussed.