The preparation of dimethyl malonate

dimethyl malonate is widely used in the chemical industry. Its preparation method is the key to chemical technology research.

In the past, dimethyl malonate was prepared by cyanide esterification. In this way, chloroacetic acid and sodium carbonate are first reacted to obtain sodium chloroacetate. Sodium chloroacetate reacts with sodium cyanide to convert into sodium cyanoacetate. After this step, sodium cyanoacetate is hydrolyzed with sulfuric acid to obtain malonic acid. Finally, malonic acid and methanol are esterified under the catalysis of sulfuric acid to obtain dimethyl malonate. However, the cyanide esterification method has many drawbacks, sodium cyanide is highly toxic, and the operation must be extremely cautious. If there is a slight error, it will endanger life, and there are many reaction wastes, which will seriously damage the environment.

With the progress of science and technology, the ester condensation method has gradually become the mainstream. Dimethyl malonate is prepared by ester condensation reaction with dimethyl carbonate and methyl acetate as raw materials under the catalysis of sodium alcohol. This method is green and environmentally friendly, the raw material dimethyl carbonate is non-toxic, the reaction conditions are mild, and the yield is quite high.

The experimental process also has many details. The ratio of raw materials must be accurate. If the ratio is out of balance, it will affect the yield. The reaction temperature and time are also critical. If the temperature is too high or too low, and the time is too long or too short, it is not conducive to the reaction. The choice and amount of catalyst have a great impact on the reaction rate and product purity.

The preparation process of dimethyl malonate is constantly evolving and innovating. From the traditional highly toxic method to the road of green and efficient, it is actually a manifestation of the progress of the chemical industry. In the future, the preparation process will be more perfect, contributing to the development of the chemical industry.