Manufacturing method of dimethyl malonate
I. INTRODUCTION
Dimethyl malonate is an important organic chemical raw material, which is widely used in the fields of pharmaceuticals, pesticides, spices, dyes and so on. Therefore, it is of great significance to study the manufacturing method of dimethyl malonate to improve the production efficiency, reduce the cost and improve the product quality. In this paper, we will introduce a manufacturing method of dimethyl malonate, which has the advantages of easy to obtain raw materials, simple operation and high yield.
II. Experimental part
1. Raw materials and reagents
Malonic acid, methanol, sulfuric acid, sodium hydroxide and so on.
2. Experimental equipments
Reactor, condenser, water separator, stirrer, etc.
3. Experimental procedure
(1) Add malonic acid and methanol to the reactor in the ratio of molar ratio 1:4 and stir well.
(2) Add appropriate amount of sulfuric acid as catalyst, control the reaction temperature at 60-70°C, and react for about 2 hours.
(3) After the reaction, cooled to room temperature, neutralized with sodium hydroxide solution to pH 7-8.
(4) Separated out the aqueous layer, the organic layer was washed with distilled water to neutral, to obtain the crude product of dimethyl malonate.
(5) The crude product was distilled and the fractions with boiling points at 100-102°C were collected to obtain pure dimethyl malonate.
III. RESULTS AND DISCUSSION
1. Yield and purity
In this experiment, the yield of dimethyl malonate reached more than 90% and the purity reached more than 99%.
2. Influence of reaction conditions on the yield
The experimental results showed that the reaction temperature, the molar ratio of methanol to malonic acid, and the dosage of catalyst had an influence on the yield. Under suitable conditions, the yield can be increased to more than 90%.
3. Generation and treatment of by-products
During the reaction process, some by-products such as methanol and water will be generated. The generation of by-products can be reduced by optimizing the experimental conditions. Meanwhile, effective treatment methods can be adopted for the generated by-products, such as distillation to recover methanol and acid-base neutralization treatment.
IV.CONCLUSION
In this study, a manufacturing method of dimethyl malonate was introduced, which has the advantages of easy availability of raw materials, simple operation and high yield. Through the optimization of experimental conditions, the yield and purity can be further improved and the cost can be reduced, which provides a feasible solution for the production of dimethyl malonate. At the same time, this study also provides certain reference and reference for the production of other chemicals.
