Benzimidazole is a potentially difunctional monomer; this paper describes our approaches to its polymerization using Reissert compound chemistry. Poly(benzimidazole Reissert compound)s (25) in which both nitrogen atoms are part of amide linkages and a cyano group is present at the 2-position of the benzimidazole ring were prepared from benzimidazole itself or bis(1-benzimidazyl)adipoyl (24) by reaction with diacid chlorides in the presence of trimethylsilyl cyanide; however, low molecular weights resulted under a variety of conditions. Attempts to synthesize polyethers by condensation of the new Reissert compound 1,3-bis(p-fluorobenzoyl)-2-cyano-2,3-dihydrobenzimidazole (14b) and Bisphenol A failed due to hydrolysis of 14b under the reaction conditions. Surprisingly, 2-benzoylbenzimidazole (16b) was formed from the base-induced rearrangement of 1,3-dibenzoyl-2-cyano-2,3-dihydrobenzimidazole (14a); the presence of radical ion intermediates during the rearrangement reaction of 14a with NaH/DMF was proven by CIDNP and ESR experiments.