Water → Ammonia

A solution of 0.83 g 8-acetyl-3-hydroxy-4-methyl-1-oxa-8-azaspiro[4.5]decane (B) in 20 ml anhydrous tetrahydrofuran was added dropwise to a mixture of 1.01 g lithium aluminum hydride and 25 ml tetrahydrofuran, and the resulting mixture was heated under reflux for three hours and then cooled in ice. Water (1.1 ml) and 10% caustic soda solution (1.1 ml) were slowly added in that order, the reaction mixture was filtered through Celite, and the insoluble matters were thoroughly washed with tetrahydrofuran and ethyl acetate. The washings were joined to the filtrate, the combined solution was concentrated, and the residue was subjected to silica gel column chromatography using, as eluent, a mixed solvent of chloroform/methanol/conc. ammonia (40:10:1), giving 8-ethyl-3-hydroxy-4-methyl-1-oxa-8-azaspiro[4.5]-decane (B) as oil. It was converted to its hydrochloride by treatment with methanolic hydrogen chloride. Yield: 0.4 g, m.p.: 150°-155° C.

1. temperaturethe resulting mixture was heated
2. temperatureunder reflux for three hours
3. temperaturecooled in ice
4. filtrationthe reaction mixture was filtered through Celite
5. washthe insoluble matters were thoroughly washed with tetrahydrofuran and ethyl acetate
6. concentrationthe combined solution was concentrated

ORD record

ord-3b8d4f4f35c94b1db23673046cf7c61a

Source dataset

uspto-grants-1991_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05041549