反应详情

Dimethyl sulfoxide (3.3 mL, 46 mmol) was dissolved in 15 mL of dichloromethane in a dry ice bath, followed by dropwise slowly addition of oxalyl chloride (2.6 mL, 31 mmol). After stirring for 45 minutes, a solution of (1-methyl-2-piperidyl)methanol 6a (1 g, 7.74 mmol) in 5 mL of dichloromethane was added dropwise to the solution. The reaction mixture was stirred for 45 minutes, then added with triethylamine (7.2 mL, 52 mmol), and stirred for 10 minutes, then warmed up to room temperature and stirred for 1 hour. The reaction mixture was washed with water (20 mL) and saturated brine (20 mL) successively. The combined organic extracts were dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure then the resulting residue was purified by alkaline alumina column chromatography with elution system A to obtain the title compound 1-methylpiperidine-2-carbaldehyde 6b (300 mg, yield 31.0%) as a brown oil, which was directly used in the next step without purification.

1. stirringThe reaction mixture was stirred for 45 minutes
2. stirringstirred for 10 minutes
3. stirringstirred for 1 hour
4. washThe reaction mixture was washed with water (20 mL) and saturated brine (20 mL) successively
5. dry with materialThe combined organic extracts were dried over anhydrous sodium sulfate
6. filtrationfiltered
7. concentrationconcentrated under reduced pressure
8. customthe resulting residue was purified by alkaline alumina column chromatography with elution system