反应详情

9.7 mL diphosgene is added dropwise over 50 minutes to a mixture of 12.85 gdiemthyl aminomalonate hydrochloride and 0.1 g activated charcoal in 25 mL dioxane under N2. The reaction mixture warms to 75°-80°C. during this time. The reaction mixture is then heated and stirred at reflux for 21/2 hours. The reaction mixture is then cooled, filtered, and concentrated to dryness by rotary evaporator, keeping exposure to moistureto a minimum. The crude product is purified by fractional distillation (bp 80°-85° C., <1 mm Hg) to give pure dimethyl isocyanatomalonate in >80% yield.

1. customwarms to 75°-80°C. during this time
2. temperatureThe reaction mixture is then heated
3. temperatureat reflux for 21/2 hours
4. temperatureThe reaction mixture is then cooled
5. filtrationfiltered
6. concentrationconcentrated to dryness by rotary evaporator
7. distillationThe crude product is purified by fractional distillation (bp 80°-85° C., <1 mm Hg)