反应详情

To a solution of 3-chlorobenzofuran-2-carboxaldehyde (1.62 g, 8.9 mmol) in methanol (50 mL) is added N-methylamine (33% solution in ethanol, 1.11 g, 35.9 mmol) and stirred overnight at room temperature. The mixture is concentrated in vacuo, re-solvated in methanol (50 mL) and cooled in an ice bath. Sodium borohydride (407 mg, 10.8 mmol) is added in portions and the mixture stirred at room temperature for 4 h. The mixture is concentrated in vacuo, re-solvated in 1.3M sodium hydroxide solution, stirred for 20 min, extracted with ethyl acetate, dried with sodium sulfate and concentrated. Purification by column chromatography (silica, CH2Cl2/MeOH, 9/1) gave title compound (1.43 g, 82%) as a colorless oil. 1H NMR (300 MHz, DMSO-d6) δ 7.55-7.63 (m, 2H), 7.33-7.42 (m, 2H), 3.93 (s, 2H), 2.27 (s, 3H).

1. concentrationThe mixture is concentrated in vacuo, re-solvated in methanol (50 mL)
2. temperaturecooled in an ice bath
3. stirringthe mixture stirred at room temperature for 4 h
4. concentrationThe mixture is concentrated in vacuo, re-solvated in 1.3M sodium hydroxide solution
5. stirringstirred for 20 min
6. extractionextracted with ethyl acetate
7. dry with materialdried with sodium sulfate
8. concentrationconcentrated
9. customPurification by column chromatography (silica, CH2Cl2/MeOH, 9/1)