Scheme 2. Synthesis of 8-Nonsubstituted 2-Quinolinone Derivatives 8 and 8a–i^,

Reagents and conditions: (a) 7 or 7a, DMT-MM, DIPEA, EtOH, rt, 21% (compound 8); (b) 7c, HATU, DIPEA, DMF, rt; (c) (i) SOCl₂, reflux, (ii) 7e or 7i, THF, 0 °C; (d) 1 N NaOH, THF, rt, 20–38% over two steps.

N-cyclohexyl-N-methylaminomethyl