Reactions of N-Substituted Pyrrole Derivatives and Related Compounds with 3, 4, 5, 6-Tetrachloro-1, 2-benzoquinone

Abstract

While furans and oxazoles give [4+2]-type cycloaddition products in the reactions with 3, 4, 5, 6-tetrachloro-1, 2-benzoquinone, 1-methyl-, 1-phenyl-, and 1-dimethylaminopyrrole and 1-methylindole afforded keto-enol-type substitution products under the same reaction conditions. The reaction of pyrroles proceeds via nucleophilic attack of the pyrroles on the n-quinoid ring.The difference in the reaction of pyrroles from that of the other heterocycles is considered to be attributable to the degree of aromaticity of these compounds.