反应详情

A solution consisting of 96 g of ethyl β-amino-β-ethoxyacrylate hydrochloride, 800 ml of methylene chloride and 120 ml of N-methylmorpholine is warmed to 40°. While stirring there is added dropwise within 2 hours a solution of 65 ml of methyl chloroformate in 350 ml of methylene chloride. After completion of the addition, the mixture is stirred at 40° for a further 2 hours. Thereupon, the resulting salt is filtered off under suction and washed with about 50 ml of methylene chloride. The filtrate is evaporated at 40° in a water-jet vacuum. There is obtained crude methyl[(1-ethoxy-2-ethoxycarbonyl)-ethylidene]carbamate in the form of a pale yellow oil which is used immediately in the next step.

1. temperatureis warmed to 40°
2. additionAfter completion of the addition
3. stirringthe mixture is stirred at 40° for a further 2 hours
4. filtrationThereupon, the resulting salt is filtered off under suction
5. washwashed with about 50 ml of methylene chloride
6. customThe filtrate is evaporated at 40° in a water-jet vacuum