Functionalization by metallation of fluoropyrazine. Diazines XXI

Article abstract of DOI:10.1016/S0040-4020(98)00173-2

Lithiation of fluoropyrazine followed by quenching with various electrophiles was successfully achieved and was used to synthesize new pyrazine derivatives. A further lithiation of 2-fluoro-3-substitute, pyrazines allowed access to 2,3,6-trisubstituted pyridazine derivatives. As an application, a one-pot synthesis of a quinuclidinylfluoropyrazine has been performed. When the 3-substituent bears a TMS protected alcohol, functionalization via metallation at C₆ position provides tetrasubstituted pyrazines in good yield.