Reaction of 2,5-dimethylpyrroles with quinones. Synthesis of new pyrrolylquinones

The reaction of 1,4-naphthoquinone (1) with 2,5-dimethylpyrroles (7a-7d) gives only 3-(1,4-naphtho-quinonyl)-2,5-dimethylpyrroles. Extending the reaction to other quinones: 5-hydroxy-1,4-naphthoquinone (2), 1,2-naphthoquinone (3), quinoline-5,8-dione (4) and quinoxaline-5,8-dione (5), of which nothing was known, allows the synthesis of new pyrrolylquinones.