反应详情

The whole of the ethyl 2-(3-difluoromethoxy-2,4,5-trifluoro-6-nitrobenzoyl)-3-ethoxyacrylate [(XVI), R1 =--OCHF2, R3' =NO2, R17 =C2H5, X=X'=F]obtained as described in step (c) above was dissolved in 500 ml of methylene chloride, and 3.5 g (0.06 moles) of cyclopropylamine were added dropwise to the resulting solution, whilst stirring and ice-cooling. The mixture was then stirred for 1 hour, whilst ice-cooling, and then for an additional 1 hour at room temperature, after which the solvent was removed by evaporation under reduced pressure. The resulting residue was subjected to silica gel column chromatography using a 9:1 by volume mixture of toluene and ethyl acetate as the eluent, to give 19.8 g of ethyl 3-cyclopropylamino-2-(3-difluoromethoxy-2,4,5-trifluoro-6-nitrobenzoyl)acrylate as an yellow powder, melting at 105°-106° C.

1. temperatureice-cooling
2. stirringThe mixture was then stirred for 1 hour, whilst ice-
3. temperaturecooling
4. customafter which the solvent was removed by evaporation under reduced pressure
5. additionby volume mixture of toluene and ethyl acetate as the eluent