2-trifluoromethylquinolines 5 are synthesized in high yields using a perfluoroalkylated gem-iodoacetoxy derivative 3 and arylamines 4. The intermediate of this reaction, 2-trifluoromethyl-1,5-diazapentadiene compound 6, was isolated. The procedures are easy, and yields are in general high. This sequence represents a valuable new synthesis of substituted 2-trifluoromethylquinolines and of 2-trifluoromethyl-diazapentadienes (vinamidine compounds).