• Metallation at the 2-position occurs readily with n-BuLi in ether (not readily in benzene). The 2,5-dilithio-derivative can be prepared in the presence of TMEDA: J. Chem. Soc., Perkin 1, 887 (1977), or with the superbasic combination of n-BuLi with KO-t-Bu: Synthesis, 316 (1988).