A solution of 7-methoxyquinolin-2(1H)-one (Intermediate 108, 310 mg, 1.8 mmol) in dry N,N-dimethylformamide (5 mL) was treated at 0° C. under stirring with lithium bis(trimethylsilyl)amide (1M in tetrahydrofuran, 1.9 mL, 1.9 mmol). The mixture was then stirred for 30 minutes at room temperature and alkylated with 2-{4-[(tert-butoxycarbonyl)amino]piperidin-1-yl}ethyl methanesulfonate (Intermediate 6, 2.03 mmol) as described for Intermediate 2. Chromatography on silica gel with dichloromethane/methanol (95:5) gave 333 mg (47%) of the product as a colorless solid.
