反应详情

A stirred solution of ethyl (2,3,4,5-tetrafluorobenzoyl)acetate (3.73 g, 14.1 mmol), Ac2O (8.50 mL, 85.7 mmol) and triethyl orthoformate (4.70 mL, 28.2 mmol) was heated at 120° C. for 3 h. The mixture was concentrated in vacuo and dried under high vacuum. To the mixture of the residue in anhydrous toluene (50 mL) was added 3-amino-3-methyl-1-butanol (1.45 g, 14.1 mmol) in anhydrous toluene (20 mL) very slowly at 0° C. and stirred at room temperature for 2 h. The solvent was removed by evaporation. Flash chromatography (EtOAc:Hexane=1:1) of the residue gave ethyl 2-(2,3,4,5-tetrafluorobenzoyl)-3-[(1-hydroxy-3-methylbutane-3-yl)amino]acrylate as a colorless solid (3.91 g, 73%).

1. concentrationThe mixture was concentrated in vacuo
2. customdried under high vacuum
3. additionTo the mixture of the residue in anhydrous toluene (50 mL)
4. customThe solvent was removed by evaporation