The Cycloaddition of Nitrilimines with 1,2-Dibenzoylethylenes

Article abstract of DOI:10.1246/bcsj.54.1429

The cycloaddition of nitrimines with 1,2-dibenzoylethylenes gave an unexpected 1,3-diaryl-4-benzoylpyrazole and benzoic acid, along with an expected cycloadduct, 1,3-diaryl-4,5-dibenzoyl-2-pyrazoline, and its dehydrogenated product, 1,3-diaryl-4,5-dibenzoylpyrazole.The elimination of the benzoyl group from the pyrazoline followed by dehydrogenation was shown to be the course of the unusual reaction.