反应详情

To a solution of methyl 2-carbamoyl-2-ethoxyiminoacetate (syn isomer) (5.22 g) in pyridine (50 ml) was dropwise added trifluoroacetic anhydride (15.7 g) below 25° C. under cooling in an ice-bath and stirring, which was continued for 30 minutes. The reaction mixture was poured into water (200 ml), followed by an addition of diisopropyl ether (200 ml). The mixture was adjusted to pH 2 with 6 N hydrochloric acid (80 ml) at 15° to 20° C. and the organic layer was separated out, washed with water, dried over magnesium sulfate and evaporated to give methyl 2-cyano-2-ethoxyiminoacetate (syn isomer) (4.23 g) as an oil.

1. temperatureunder cooling in an ice-bath
2. customthe organic layer was separated out
3. washwashed with water
4. dry with materialdried over magnesium sulfate
5. customevaporated