Undergoes vicarious nucleophilic substitution of hydrogen at the 4-position; e.g., with chloromethyl phenyl sulfone and base, 2-bromo-5-nitro-4-(phenylsulfonylmethyl)thiophene is formed in 92% yield: Tetrahedron, 51, 8339 (1995). For a review of vicarious nucleophilic substitution in heterocyclic compounds, see: Synthesis, 103 (1991).