反应详情

Under a nitrogen atmosphere, in a dry 500 mL 3-necked flask, add LiAlH4 (0.87 g) and THF (dried over Mol sieves) (96 mL) and cool to 10 C (ice bath). Add AlCl3 (3.33 g) portionwise keeping the temperature at ˜10 C. Heat to 50-60 C for 30 min., then cool to −40 to −50 C, Add 1,1-dimethylethyl 1-oxo-3-(4-chlorophenyl)-2-isopropyl-2,7-diazaspiro[3.5]nonane-7-carboxylate (5.75 g in dry THF (150 mL). Warm the reaction mixture to −20 C and monitor at 15 min intervals until starting material is gone (˜60 min.). At −30 C, quench the reaction mixture at ˜−30 C with 10% NaOH, then warm to room temperature. Extract with diethyl ether (2×300 mL). Extract the diethyl ether with brine, Concentrate the dried (MgSO4) Et2O in vacuo to give the title compound as a viscous oil (9.79 g). Add EtOAc (5 mL) and hexane (25 ml) and let stand at RT to give the title compound as a white solid (0.031 g). Filtrate (4.47 g) in EtOAc (30 mL) and hexane (30 mL) gave additional compound (3.56 g) which was placed on an Analogix system: Column of silica gel (115 g) and eluted with hexane/EtOAc, 20 mL fractions collected. Concentration of fraction 54-145 gave the title compound (2.94 g) as a white solid.

1. temperaturecool to 10 C (ice bath)
2. temperatureHeat to 50-60 C for 30 min.
3. temperaturecool to −40 to −50 C
4. temperatureWarm the reaction mixture to −20 C
5. custom(˜60 min.)
6. customAt −30 C, quench the reaction mixture at ˜−30 C with 10% NaOH
7. extractionExtract with diethyl ether (2×300 mL)
8. extractionExtract the diethyl ether with brine
9. concentrationConcentrate the
10. dry with materialdried (MgSO4) Et2O in vacuo