反应详情

N-tert-Butyloxycarbonylpiperidone (5.9 g, 29.8 mmol) and triethylamine (3.02 g, 29.8 mmol) were added to a solution of (S)-methioninamide hydrochloride (5.5 g, 29.8 mmol) in dry EtOH (66 ml) and the mixture was heated for 2.5 h under reflux. After addition of water (50 ml) and CH2Cl2 (200 ml), the organic phase was separated off and the aqueous phase was extracted with CH2Cl2 (3×20 ml). The combined organic phases were dried over Na2SO4. After filtration, the solvent was distilled off. tert-Butyl 3-(S)-(2-methylsulfanylethyl)-2-oxo-1,4,8-triazaspiro[4,5]decane-8-carboxylate was obtained in a yield of 8.0 g (82%).

1. temperaturethe mixture was heated for 2.5 h
2. temperatureunder reflux
3. customthe organic phase was separated off
4. extractionthe aqueous phase was extracted with CH2Cl2 (3×20 ml)
5. dry with materialThe combined organic phases were dried over Na2SO4
6. filtrationAfter filtration
7. distillationthe solvent was distilled off