Firstly, ethyl acetate (880kg, 10kmol) and 40% dimethylamine aqueous solution (1237.5kg, 11kmol) were pumped into 3000L stainless steel kettle sequentially, the motor was turned on for stirring, and formic acid (690kg, 15kmol) was pumped into the kettle after homogeneous stirring. At the end of feeding, steam was introduced into the jacket of the reactor, and the temperature inside the reactor was warmed up to 125C. At this time, the pressure of the reaction system was about 0.2MPa, and then nitrogen was introduced into the reactor to pressurize it to 0.55MPa, and then it started to hold the reaction for 16h. When the pressure dropped during the period of heat preservation, nitrogen was introduced into the reactor to keep the pressure stable at 0.55MPa.
After the heat preservation ended, nitrogen was introduced into the reactor to keep the pressure stable at 0.55MPa. After the cooling was completed, the resulting material was transferred to a freeze dryer, and the moisture content in the product was made to be less than 0.5% by the freeze drying process, so as to obtain a crude product of ethyl 3-(N,N-dimethylamino)acrylate.
By the end of the lyophilization, the crude ethyl N,N-dimethylaminoacrylate was transferred to a distillation kettle and subjected to decompression distillation at a vacuum of 0.095 MPa and a temperature of 150 C, to obtain 1314.2 kg of colorless and transparent ethyl 3-(N,N-dimethylamino)acrylate finished product, with a molar yield of 91.9% and a gas chromatographic purity of 99.52%.
