反应详情

A mixture of 1-benzyl 4-methyl 4-(2-oxoethyl)piperidine-1,4-dicarboxylate (4.80 g, 0.0150 mol), trans-4-aminocyclohexanol hydrochloride (2.5 g, 0.016 mol) and triethylamine (3.3 mL, 0.024 mol) in 1,2-dichloroethane (30.0 mL) was stirred at room temperature for 30 min. To the mixture was added sodium triacetoxyborohydride (7.9 g, 0.038 mol) with stirring. The mixture was stirred at room temperature for 1 h, then was heated at 80° C. for 2 h. After cooling, the mixture was diluted with dichloromethane, and washed with 1N HCl solution, NaHCO3 (7.5%), water, and brine successively, dried over Na2SO4, filtered, and concentrated. The residue was purified by flash chromatography to give benzyl 2-(trans-4-hydroxycyclohexyl)-1-oxo-2,8-diazaspiro[4.5]decane-8-carboxylate (4.20 g, 72.0%).

1. stirringwith stirring
2. stirringThe mixture was stirred at room temperature for 1 h
3. temperaturewas heated at 80° C. for 2 h
4. temperatureAfter cooling
5. washwashed with 1N HCl solution, NaHCO3 (7.5%), water, and brine successively
6. dry with materialdried over Na2SO4
7. filtrationfiltered
8. concentrationconcentrated
9. customThe residue was purified by flash chromatography