1. Obtained from the reaction of methyl chloroformate ([79-22-1]) with methanol. The raw material methyl chloroformate used in the reaction is obtained by reacting methanol with phosgene. During the preparation, this phosgenation product can also be synthesized by adding excess methanol and refluxing to synthesize dimethyl carbonate. The above reaction is called traditional phosgene method.
2. Transesterification method Dimethyl carbonate can be obtained by transesterification of ethylene carbonate or propylene carbonate with methanol. This method has a high yield, a small equipment corrosion, and mild reaction conditions, but the source of raw materials is restricted by the development of the petrochemical industry and the utilization of elements is low.
3. Oxidative carbonylation methanol, carbon monoxide, and oxygen are used to directly synthesize dimethyl carbonate under the action of a catalyst. This method is cheap, easy to obtain, has little toxicity, and has a simple process. It is the most promising method. According to the classification of process conditions, it can be divided into liquid-phase method and gas-phase method. Gas-phase method can be divided into one-step method and two-step method. Among them, the two-step method of methanol liquid-phase oxidative carbonylation and gas-phase oxidative carbonylation has been industrialized, and the one-step methanol carbonylation carbonylation method is still under development.
4. Synthesis of methanol and CO2 reaction. This process route is still under development.
5. Methanol and urea reaction synthesis method. This process route is still under development.