The mixture of lithium diisopropylamide and potassium tert-butoxide (“LIDA-KOR reagent”) is a powerful base which can be advantageously employed for the regioselective deprotonation of fluoropyridines and, in particular, 3-fluoroquinoline. A novel cyclization process was elaborated for the preparation of the latter product.
N-(Fluoro-3-methoxyacryloyl)anilines [2-fluoro-3-methoxyprop-2-enanilides] can be prepared by condensation between lithium anilides and methyl 2-fluoro-3-methoxyprop-2-enoate. Under strongly acidic conditions, these intermediate undergo a cyclization reaction accompanied by elimination of methanol to afford 3-fluoro-2-quinolones. Substituents occupying the para or ortho position of the aniline appear at the heterocyclic