反应详情

To tert-butyl (3-oxocyclobutyl)carbamate (see PREPARATION 4A, STEP 1; 110 g, 0.594 mol, 1 eq) in ethanol (600 mL) was slowly added sodium borohydride (11.23 g, 0.297 mol, 0.5 eq) at 0° C. Reaction mixture was warmed to RT and stirred at this temperature for 2 h. It was quenched with water (1 L). Solvent was removed under reduced pressure. Water layer was extracted with EtOAc (3×2 L). Combined organic layer was washed with brine, dried over magnesium sulfate, filtered and concentrated. Residue was purified by column chromatography with aluminum oxide (Eluent: 20% EtOAc in hexane to 10% MeOH in DCM) to get 64 g of tert-butyl (3-hydroxycyclobutyl)carbamate as a white solid in 58% yield.

1. customat 0° C
2. customReaction mixture
3. customIt was quenched with water (1 L)
4. customSolvent was removed under reduced pressure
5. extractionWater layer was extracted with EtOAc (3×2 L)
6. washCombined organic layer was washed with brine
7. dry with materialdried over magnesium sulfate
8. filtrationfiltered
9. concentrationconcentrated
10. customResidue was purified by column chromatography with aluminum oxide (Eluent: 20% EtOAc in hexane to 10% MeOH in DCM)