反应详情

A stirred solution of 3-oxo-3-(2,3,4,5-tetrafluorophenyl)propionate (3.67 g, 13.9 mmol), Ac2O (7.89 mL, 83.5 mmol) and triethyl orthoformate (4.63 mL, 27.8 mmol) was heated at 120° C. for 3 hours. The mixture was concentrated in vacuo and dried under high vacuum. 1-amino-1-(2-hydroxyethyl)cyclobutane (1.60 g, 13.9 mmol) in anhydrous toluene (20 mL) was added slowly at 0° C. to a solution of the mixture in anhydrous toluene (50 mL). The resulting mixture was stirred at room temperature for 2 hours, and the solvent was removed by evaporation. Flash chromatography (AcOEt:Hexane=1:1) of the residue gave the title compound as a pale yellow solid (3.30 g, 61%). 1H-NMR (400 MHz, CDCl3) δ 0.96 (0.6H, t, J=7.3 Hz), 1.09 (2.4H, t, J=7.3 Hz), 1.85-2.03 (12H, m), 2.06-2.13 (2H, m), 2.20-2.30 (2H, m), 2.32-2.43 (2H, m), 3.82-3.88 (2H, m), 4.02 (0.4H, q, J=7.3 Hz), 4.07 (1.6H, q, J=7.3 Hz), 6.94-7.03 (0.2H, m), 7.05-7.13 (0.8H, m), 8.23-8.30 (1H, m), 10.05-10.17 (0.2H, m), 11.36-11.50 (0.8H, m).

1. concentrationThe mixture was concentrated in vacuo
2. customdried under high vacuum
3. customthe solvent was removed by evaporation