Ethyl 5-(4-Bromophenyl)-4-methyl-1H-pyrrole-2-carboxylate.

This note describes a sequence converting an oxime-substituted pyrrolidine into a trisubstituted pyrrole structure. The synthetic route is based on a double chlorination of the pyrrolidine substrate followed by the base induced formation of both an imine and a nitrile oxide functionality. The latter reacts with an immobilized thiourea to yield an isothiocyanate which upon elimination generates the final pyrrole in an unprecedented cascade of events