反应详情

tert-Butyl 4-(1-bromo-2-oxoethyl)piperidine-1-carboxylate (WO 0059502: 21.0 g) and a solution of N,N′-dimethylthiourea (6.0 g) in ethanol (300 mL) were heated under reflux. The reaction solution was concentrated, and the residue was dissolved in ethyl acetate and water. The aqueous layer was collected by separation. The aqueous layer was basified with an aqueous potassium carbonate solution, and extracted with chloroform. The extract was dried over anhydrous sodium sulfate, and then the solvent was distilled off to give the title compound (12.2 g) as a pale yellow solid.

1. temperatureunder reflux
2. concentrationThe reaction solution was concentrated
3. dissolutionthe residue was dissolved in ethyl acetate
4. customThe aqueous layer was collected by separation
5. extractionextracted with chloroform
6. dry with materialThe extract was dried over anhydrous sodium sulfate
7. distillationthe solvent was distilled off