反应详情

0.58 g (8.36 mmol) of hydroxylamine hydrochloride and 1.15 g (8.36 mmol) of potassium carbonate are added to a solution of 1.00 g (4.18 mmol) of tert-butyl 2-oxo-7-azaspiro[3.5]nonane-7-carboxylate (U.S. Pat. No. 6,498,159) in 60 mL of ethanol, and the mixture is then left stirring at room temperature for 12 hours. After evaporating off the solvent under reduced pressure, the residue is taken up in dichloromethane and water, the aqueous phase is separated out and extracted twice with dichloromethane, and the combined organic phases are dried over sodium sulfate. After evaporating off the solvent, the residue obtained is purified by chromatography on silica gel, eluting with a 99/1/0.1 mixture of dichloromethane, methanol and 28% aqueous ammonia. 0.831 g of pure product is thus obtained in the form of a white powder.

1. customAfter evaporating off the solvent under reduced pressure
2. customwater, the aqueous phase is separated out
3. extractionextracted twice with dichloromethane
4. dry with materialthe combined organic phases are dried over sodium sulfate
5. customAfter evaporating off the solvent
6. customthe residue obtained
7. customis purified by chromatography on silica gel
8. washeluting with a 99/1/0.1 mixture of dichloromethane, methanol and 28% aqueous ammonia