反应详情

温度

-78 °C

The 1-(4-methoxy-benzyl)-3,4-dihydro-1H-quinolin-2-one (7.86 mmol) obtained in the previous step is dissolved in 10 mL of anhydrous THF. A solution of freshly prepared LDA (9.43 mmol) in 3.5 mL of anhydrous THF is added dropwise at −78° C. The reaction mixture is stirred at −78° C. for 10 minutes, warmed up to 0° C. for 15 minutes, and then cooled down to −78° C. again before it is transferred dropwise through a double-ended needle to a solution of tert-butyl bromoacetate (10.2 mmol) in 5 mL of anhydrous THF. The resultant solution is stirred at —78° C. for 1 hour before it is allowed to warm up to 0° C. within another hour and then quenched with MeOH. After removal of the solvent, the residue is purified by silica gel chromatography (hexane/EtOAc) to give [1-(4-methoxy-benzyl)-2-oxo-1,2,3,4-tetrahydro-quinolin-3-yl]-acetic acid tert-butyl ester as a light yellow oil. Yield: 53%. 1H NMR (400 MHz, CDCl3): δ 7.13 (m, 4H), 6.96 (t, 1H), 6.90 (d, 1H), 6.83 (d, 2H), 5.25 (d, 1H), 4.95 (d, 1H), 3.76 (s, 3H), 3.13 (m, 1H), 3.00-2.85 (m, 3H), 2.41 (dd, 1H), 1.48 (s, 9H). MS: (ES+): 404.2 [M+23].

1. temperaturewarmed up to 0° C. for 15 minutes
2. temperaturecooled down to −78° C. again before it
3. temperatureto warm up to 0° C. within another hour
4. customquenched with MeOH
5. customAfter removal of the solvent
6. customthe residue is purified by silica gel chromatography (hexane/EtOAc)