反应详情

4-fluorocinnamic acid (25 g) was suspended in dichloromethane (300 ml); under ice cooling and stirring, DMF (0.5 ml) and then oxalyl chloride (15.36 ml) were added drop by drop; the same temperature was kept for 3 hours and gradually returned to room temperature. Under reduced pressure, the solvent was distilled off; the residue was dissolved in ethyl acetate (100 ml). This solution was added drop by drop to an ice-cooled mixed solution of 25% aqueous ammonia (250 ml) and ethyl acetate (52.5 ml). The reaction mixture was extracted with ethyl acetate (400 ml×2) and washed with saturated saline, after which it was dried over anhydrous magnesium sulfate. Under reduced pressure, the solvent was distilled off; the precipitated crystal was collected by filtration and dried to yield (E)-3-(4-fluorophenyl)-2-propenamide (24.4 g).

1. customgradually returned to room temperature
2. distillationUnder reduced pressure, the solvent was distilled off
3. dissolutionthe residue was dissolved in ethyl acetate (100 ml)
4. additionThis solution was added drop by drop to an ice-
5. temperaturecooled
6. additionmixed solution of 25% aqueous ammonia (250 ml) and ethyl acetate (52.5 ml)
7. extractionThe reaction mixture was extracted with ethyl acetate (400 ml×2)
8. washwashed with saturated saline
9. dry with materialafter which it was dried over anhydrous magnesium sulfate
10. distillationUnder reduced pressure, the solvent was distilled off
11. filtrationthe precipitated crystal was collected by filtration
12. customdried