Reaction of 5-Amino-1-phenylpyrazole-4-carbonitriles with Dimethyl Acetylenedicarboxylate. Synthesis and Structural Determination of Trimethyl 4,8-Dioxo-1-phenyl-4,5,5a,8-tetrahydro-1H-pyrazolo[3,4-e]indolizine-5,5a,6- tricarboxylate Derivatives

Article abstract of DOI:10.1002/jhet.5570340244

The reaction of 5-amino-1-phenylpyrazole-4-carbonitriles 1a-c with dimethyl acetylenedicarboxylate in the presence of potassium carbonate in dimethyl sulfoxide gave trimethyl 4,5,5a,8-tetrahydro-1-phenyl-4,8-dioxo-1H-pyrazolo[3,4-e]indolizine-5,5a,6- tric