Cl[C:2]1[N:14]=[CH:13][CH:12]=[CH:11][C:3]=1[C:4]([O:6][C:7]([CH3:10])([CH3:9])[CH3:8])=[O:5].[CH3:15][NH2:16].CO>>[CH3:15][NH:16][C:2]1[N:14]=[CH:13][CH:12]=[CH:11][C:3]=1[C:4]([O:6][C:7]([CH3:10])([CH3:9])[CH3:8])=[O:5]t-Butyl 2-chloronicotinate (k) (50.0 g, 0.234 mol) was dissolved in a 40% methylamine-methanol solution (300 mL) and the mixture was stirred at room temperature for 30 h. The mixture was evaporated under reduced pressure and the resulting residue was dissolved in EtOAc (750 mL). The EtOAc solution was washed with water, dried over MgSO4 and evaporated under reduced pressure. The obtaining oily crude product was purified by a short silica gel column chromatography (ca. 300 g of silica gel, eluent: EtOAc/hexane=1/3) to give t-butyl 2-(N-methylamino)nicotinate (1) (45.0 g, ca. 92%) contaminated by starting meterial; 1H NMR (CDCl3): δ 1.57 (s, 9H), 3.05 (d, J=5.0 Hz, 3H), 6.49 (dd, J=4.6 and 7.6 Hz, 1H), 7.96 (bs, 1H), 8.04 (dd, J=2.0 and 7.6 Hz, 1H), 8.28 (dd, J=2.0 and 4.6 Hz, 1H).
불러오는 중…