One-Pot Synthesis of 3-Fluoro-4-(trifluoromethyl)quinolines from Pentafluoropropen-2-ol and Their Molecular Modification

Pentafluoropropen-2-ol (PFP) was prepared by the reaction of hexafluoroacetone (HFA) with Mg/TMSCl. The one-pot tandem sequential reactions of PFP via Mannich addition with aldimines followed by Friedel−Crafts cyclization and aromatization afforded the title quinolines. A variety of corresponding 3-substituted quinolines were derived from the title quinoline by nucleophilic substitution of 3-fluorine with nucleophiles. A defluorinative transformation of the 4-trifluoromethyl group of the title quinoline with hydrazine afforded pyrazoloquinoline.