反应详情

A mixture of dimethyl ethoxyiminomalonate (57.4 g) and conc. ammonium hydroxide (50 ml) in methanol (150 ml) was stirred for 2.5 hours at room temperature. The mixture was adjusted to pH 4 with conc. hydrochloric acid under cooling and concentrated to 70 ml under reduced pressure. The aqueous solution was stood in a refrigerator for one hour and the resulting precipitates were collected by filtration, washed with cold water and dried to give methyl 2-carbamoyl-2-ethoxyiminoacetate (syn isomer) (31 g), mp 68° to 71° C.

1. temperatureunder cooling
2. concentrationconcentrated to 70 ml under reduced pressure
3. waitThe aqueous solution was stood in a refrigerator for one hour
4. customthe resulting precipitates
5. filtrationwere collected by filtration
6. washwashed with cold water
7. customdried