Scheme 3. Synthesis of 8-Methylamino-2-Quinolinone Derivatives 13 and 13a–h.

Reagents and conditions: (a) tributyl(vinyl)tin, Pd(tert-Bu₃P)₂, CsF, toluene, 140 °C, microwave, 91%; (b) OsO₄, NaIO₄, 1,4-dioxane, H₂O, rt, 70%; (c) Fe, NH₄Cl, EtOH, H₂O, 75 °C, 46%; (d) diethyl malonate, piperidine, EtOH, 75 °C; (e) 1 N NaOH, THF, rt, 63% over two steps; (f) 7 or 7a–h, HATU, DIPEA, DMF, rt, or 60 °C; (g) 1 N NaOH, THF, rt, 6–58% over two steps.