First reactions of 1,4-dimethylcarbazole-3-carbaldehyde N,N-dimethyl-hydrazone with carbo- and azodienophiles

Instead of giving the primarily expected Diels-Alder adducts, attack of the electrophilic dienophiles at the hydrazone unit of title compound occurs to furnish a 3-cyanocarbazole and, in one case, a carbazolyl-urazolylhydrazone.