Abstract

Industrial demand for thiophene and its derivatives has escalated since 1980. Applications in the electronic field will take it into the twenty-first century, whereas pharmaceutical, agrochemical, and dyestuff requirements continue to account for existing demands. Synthesis of the parent ring system, along with simple alkyl derivatives, has changed little over the years. An outline of the vapor-phase route, the best practical environmental option to produce these materials, is given. Ring synthesis of specific derivatives has been developed into commercial-scale operations from chemistry identified in the late 1950s and early 1960s, following market interest in such products as dyestuff, agrochemical, and pharmaceutical intermediates. Reactions of the thiophene have been noted, along with useful spectroscopic and physical chemistry data as well as additional toxicity and ecotoxicity data for thiophene derivatives. Biotic degradation of thiophene is minimal, and halothiophenes, in particular, are environmentally hazardous in aqueous systems.