构建四氢异喹啉的实验操作In a 1-L three-neck round-bottom flask cooled in a room temperature water bath, (2,2-dimethoxy-ethyl)-methyl-amine (12.1 mL, 94.2 mmol, 1.0 equiv) was added to a solution of 3-benzyloxy-benzaldehyde (20.0 g, 94.2 mmol, 1.0 equiv) in CH2Cl2 (300 mL). NaBH(OAc)3 (24.0 g, 113 mmol, 1.2 equiv) was added in portions. The reaction mixture was stirred at room temperature for 18 h. Saturated aqueous NaHCO3 solution (300 mL) was added, and the mixture was stirred for 2 h. The organic layer was separated, dried over Na2SO4, and evaporated to afford 12 as a colorless oil (29.2 g, 92.3 mmol, 98%).
In a 3-L one-neck round-bottom flask equipped with a magnetic stir bar, 12 (100 g, 0.32 mol, 1.0 equiv) was diluted in 6 mol/L aqueous HCl solution (600 mL). The reaction mixture was stirred at 40 °C for 18 h and then cooled to 0 °C. With vigorous stirring, NaOH pellets were slowly added until pH ) 13. The basic aqueous solution was extracted with EtOAc (200 mL × 3). The combined organic layers were dried over Na2SO4 and concentrated to afford a slightly yellow oil. The crude oil was purified on a plug of silica gel (20 cm OD, 4 in. height) with 95/5 EtOAc/MeOH as the eluents to afford 11 as a yellow solid (77 g, 0.28 mol, 90%). 参考文献Organic Process Research & Development 2007, 11, 1043–1050
