反应详情

0.89 g (23.57 mmol) of sodium borohydride is added portionwise at 0° C. to a solution of 3.54 g (15.71 mmol) of tert-butyl 2-oxo-6-azaspiro[3.4]octane-6-carboxylate (WO98/06720) diluted in 40 mL of methanol. The reaction mixture is stirred at room temperature for 1 hour 30 minutes. After evaporating off the solvent, water is added to the reaction medium, the aqueous phase is separated out and extracted several times with diethyl ether, the combined organic phases are washed with saturated aqueous sodium chloride solution and dried over sodium sulfate, and the filtrate is concentrated under reduced pressure. After evaporating off the solvent, 3.10 g of product are obtained in the form of a brown oil, which is used without further purification in the following step.

1. customAfter evaporating off the solvent, water
2. additionis added to the reaction medium
3. customthe aqueous phase is separated out
4. extractionextracted several times with diethyl ether
5. washthe combined organic phases are washed with saturated aqueous sodium chloride solution
6. dry with materialdried over sodium sulfate
7. concentrationthe filtrate is concentrated under reduced pressure
8. customAfter evaporating off the solvent, 3.10 g of product
9. customare obtained in the form of a brown oil, which
10. customis used without further purification in the following step