Synthesis of Trisubstituted Thiophenes via a Halogen Dance Reaction at 2-Bromo-5-methylthiophene

Article abstract of DOI:10.1007/BF00813799

A new example of a selective halogen dance reaction was observed upon lithiation of 2-bromo-5-methylthiophene with LDA under appropriate reaction conditions. A series of 2-substituted 3-bromo-5-methylthiophenes was prepared by reacting the thus selectively generated intermediate 3-bromo-2-lithio-5-methylthiophene with various electrophiles to study scope and limitations of the reaction.