反应详情

4.3 g of cyclopropylamine are added dropwise to a stirred ice-cooled solution of 24.9 g of ethyl 2-(2,4-dichloro-5-fluoro-benzoyl)-3-ethoxy-acrylate (5) in 80 ml of ethanol. When the exothermic reaction has died down, stirring is continued for a further hour at room temperature, the solvent is stripped off in vacuo and the residue is recrystallised from cyclohexane/petroleum ether. 22.9 g of ethyl 2-(2,4-dichloro-5-fluoro-benzoyl)-3-cyclopropylamino-acrylate (6) of melting point 89°-90° C. are obtained.

1. customWhen the exothermic reaction
2. waitis continued for a further hour at room temperature
3. customthe residue is recrystallised from cyclohexane/petroleum ether