Undergoes vicarious nucleophilic substitution at the 4-position; e.g. with chloromethyl phenyl sulfone and base, 5-nitro-4-(phenylsulfonylmethyl)thiophene-2-carbonitrile is formed in 91% yield: Tetrahedron, 51, 8339 (1995).
For a review of vicarious nucleophilic substitution in heterocyclic compounds, see: Synthesis, 103 (1991).