反应详情

A stirred suspension of 2-amino-2-methylpropanoic acid (165 g) in ethanol at 0° C. was saturated with hydrogen chloride gas. The mixture was heated at reflux for 4 hours and the solvent was evaporated under reduced pressure to give ethyl 2-amino-2-methylpropanoate hydrochloride as a white solid. Sodium carbonate (100 g) was slowly added to a suspension of the solid in water followed by 40% aqueous formaldehyde solution (150 g) and the suspension was stirred for 3 hours. The mixture was extracted with ether, the organic solution was washed with water, dried (magnesium sulphate) and solvent evaporated under reduced pressure to give ethyl 2-(N-methyleneamino)-2-methylpropanoate (137.8 g) in equilibrium with its trimer 1,3,5-tri(1-ethoxycarbonyl-1-methylethyl)hexahydrotriazine as a colourless oil, IR (liquid film) 2980(s), 1725(vs), 1250(s), 1140(vs).

1. temperatureThe mixture was heated
2. temperatureat reflux for 4 hours
3. customthe solvent was evaporated under reduced pressure