Synthesis of dimethyl malonate

1. Preparation of raw materials
To synthesize dimethyl malonate (Dimethyl Malonate), the first thing is to prepare the required raw materials. The main raw materials are cyanoacetic acid and methanol. Cyanoacetic acid needs to be of high quality and purity to ensure a smooth reaction. Methanol also needs to meet the corresponding purity standards, without impurities interfering with the reaction process.

Second, the reaction process
Slowly pour the measured cyanoacetic acid into the reactor with an appropriate amount of methanol. This process needs to pay attention to the pouring speed to prevent overreaction. Then, add an appropriate amount of concentrated sulfuric acid as a catalyst. The amount of concentrated sulfuric acid needs to be precisely controlled. Too much or too little will affect the reaction rate and yield. Immediately, turn on the stirring device to fully mix the reactants evenly. Heat the reactor and gradually increase the temperature to a specific range. At this temperature, cyanoacetic acid and methanol are esterified under the catalysis of concentrated sulfuric acid, resulting in dimethyl malonate and water. During the reaction process, it is necessary to closely monitor the temperature and reaction progress, and adjust the heating power and stirring speed in a timely manner.

Third, after the product separation and purification
After the reaction is completed, wait for the reaction liquid to cool and transfer it to the separation funnel. Due to the fact that the dimethyl malonate formed by the reaction is insoluble with water and has different densities, stratification will occur. Carefully separate the lower organic phase, which is the crude product containing dimethyl malonate. In order to obtain high-purity dimethyl malonate, the crude product needs to be purified. Using the method of distillation, according to the boiling point characteristics of dimethyl malonate, by controlling the distillation temperature, dimethyl malonate is distilled from the crude product, and the fraction in a specific temperature range is collected, which is the purified dimethyl malonate. Through this step, the purity of dimethyl malonate can be greatly improved to meet the subsequent use needs.