反应详情

温度

100 °C

To a freshly prepared solution of sodium ethoxide (prepared by addition of 1.11 g, 48.35 mmol Na metal in 8 mL EtOH) in EtOH was added a solution of ethyl difluoroacetate (5.0 g, 40.29 mmol) in EtOAc (9 mL) at rt and the reaction mixture was heated at 65° C. for 2 h. Then the reaction mixture was quenched with 1N HCl at rt and the pH was adjusted to 6-7. Then the reaction mixture was extracted with EtOAc and the organic layer was washed with water and brine, separated, dried, filtered and concentrated to afford 5.5 g of ethyl 4,4-difluoro-3-oxobutanoate which was taken to the next step without further purification. To a mixture of ethyl 4,4-difluoro-3-oxobutanoate (5.5 g, 33.11 mmol) and triethyl orthoformate (12 mL, 66.26 mmol) was added acetic anhydride (27.0 g, 265.0 mmol) and the reaction mixture was heated at 100° C. for 12 h. Then the reaction mixture was concentrated to afford 5.5 g of the title product which was taken to the next step without further purification.

1. customwas taken to the next step without further purification
2. concentrationThen the reaction mixture was concentrated