A simple strategy for the preparation of 4-aminoquinolines from β-functionalized enamines

Article abstract of DOI:10.1016/S0040-4020(97)10372-6

An easy and efficient synthesis of 4-aminoquinolines substituted with a phosphine oxide group in the 3-position 1, is described. The key step is a heterocyclization of cyano-aryl β-enamino phosphine oxides 4. The treatment of β-enamines derived from phosphonium salts 7, with a base afforded phosphazenes 8 and the hydrolysis of these phosphazenes led to the formation of substituted 4-aminoquinolines 9.