反应详情

A solution of ethyl (3-methoxy-2,4,5-trifluorobenzoyl)acetate (12, 7.6 g, 27.5 mmol), Ac2O (6.5 mL, 69 mmol) and triethyl orthoformate (6.9 mL, 41 mmol) was heated at 150° C. for 1.5 h. The mixture was concentrated in vacuo and dried under high vacuum for 3 hours. The crude product 13 was dissolved in ethanol (50 mL) and cyclopentyl amine (2.8 mL, 27 mmol) was added very slowly at 0° C. After 1.5 h, the solvent was removed by evaporation to yield 14 as a dark yellow solid (9.55 g crude, quantitative).

1. concentrationThe mixture was concentrated in vacuo
2. customdried under high vacuum for 3 hours
3. dissolutionThe crude product 13 was dissolved in ethanol (50 mL)
4. customthe solvent was removed by evaporation