反应详情

Into a 2000-mL 4-necked round-bottom flask was placed a solution of 3-oxocyclobutane-1-carboxylic acid (114 g, 999.13 mmol, 1.00 equiv) in dichloromethane (400 mL), 2-methylpropan-2-ol (102 g, 1.38 mol, 1.37 equiv), N,N-dimethylpyridin-4-amine (67.2 g, 550.06 mmol, 0.55 equiv), followed by the addition of a solution of N—(N-cyclohexylcarboximidoyl)cyclohexanamine (226.6 g, 1.10 mol, 1.10 equiv) in dichloromethane (300 mL) dropwise with stirring at room temperature over 25 min. The resulting solution was stifled overnight at room temperature. The solids were filtered out and the filtrate was washed with 2×500 mL of HCl (1 M) and 1×500 mL of saturated aqueous NaHCO3, and concentrated under vacuum. The residue was diluted with 500 mL of hexane. The mixture was decolorized by 50 g of active carbon and stirring for 3 minutes. The solids were filtered out and the filtrate was concentrated under vacuum to afford 102 g (60%) of tert-butyl 3-oxocyclobutane-1-carboxylate as a light yellow liquid.

1. customInto a 2000-mL 4-necked round-bottom flask was placed
2. waitThe resulting solution was stifled overnight at room temperature
3. filtrationThe solids were filtered out
4. washthe filtrate was washed with 2×500 mL of HCl (1 M) and 1×500 mL of saturated aqueous NaHCO3
5. concentrationconcentrated under vacuum
6. additionThe residue was diluted with 500 mL of hexane
7. stirringstirring for 3 minutes
8. filtrationThe solids were filtered out
9. concentrationthe filtrate was concentrated under vacuum