To a cold solution of a compound of formula IV, preferably 2-benzoyl-[3,3-di(ethoxycarbonyl)propyl]pyrrole, in an aprotic polar solvent, such as tetrahydrofuran, is added a slight excess of a strong base, preferably sodium hydride. The reaction mixture is allowed to stir for about 30 minutes. To the reaction mixture is then added a halogenating agent, preferably N-bromosuccinimide. The reaction mixture is allowed to stir until complete The mixture is poured into water and extracted with an aprotic polar solvent, such as diethyl ether. The organic layers are combined, washed with water and brine, dried, and concentrated under reduced pressure. The residue may be purified by conventional means to produce a compound of formula VII, preferably 2-benzoyl-[3-bromo-3,3-di(ethoxycarbonyl)propyl]pyrrole.
