Dimethyl carbonate (DMC) is a chemical raw material with low toxicity, excellent environmental protection performance and wide applications. It is an important intermediate in organic synthesis, and its molecular structure contains functional groups such as carbonyl, methyl and methoxy.

It is a colorless, transparent, slightly odorous and slightly sweet liquid at room temperature, with a melting point of 4℃, a boiling point of 90. 1℃ and a density of 1.069 g/cm3. It is almost insoluble in water, but miscible with almost all organic solvents, such as alcohol, ether and ketone. DMC and methanol boil at atmospheric pressure, and the boiling temperature is 63.8℃.

It has a variety of reaction properties and is characterized by safety, convenience, less pollution and easy transportation in production. Dimethyl carbonate has low toxicity and is a "green" chemical product with great development prospect.

DMC has low toxicity, and 1992 is classified as a non-toxic product in Europe. It is an environment-friendly chemical raw material that meets the requirements of modern "clean technology". Therefore, the synthesis technology of dimethyl carbonate has received extensive attention from the chemical industry at home and abroad, and was listed as a key project by the Ministry of Chemical Industry of China during the Eighth Five-Year Plan and the Ninth Five-Year Plan.

DMC has a unique molecular structure (CH3O-CO-OCH3) and excellent properties, so it is widely used, mainly as carbonylation and methylation reagents, gasoline additives, raw materials for synthesizing polycarbonate (PC) and so on. The large-scale production of dimethyl carbonate is developed with the non-phosgene synthesis process of polycarbonate.

Extended data

The excellent performance and special molecular structure of DMC determine the wide application of DMC, which is summarized as follows:

1, replacing phosgene as carbonylation reagent.

Although the reaction activity of phosgene (Cl-CO-Cl) is high, its toxic and corrosive by-products make it face great environmental pressure, so it will be phased out. When the carbonyl group of DMC is attacked by nucleophiles, the acyl oxygen bond is broken to form carbonyl compounds, and the by-product is methanol, so DMC can replace phosgene as a safe reaction reagent to synthesize carbonic acid derivatives.

2. Replace dimethyl sulfate as methylation reagent.

For reasons similar to phosgene, methyl sulfate (CH3O-SO-OCH3) is also facing the pressure of being eliminated. When the methyl carbon of DMC is attacked by nucleophiles, its alkoxy bond is broken and methylated products are also produced. In addition, using DMC has higher reaction yield and simpler process than using dimethyl sulfate. The main uses include the synthesis of organic intermediates, pharmaceutical products, pesticide products and so on.

3. Low toxic solvent

DMC has excellent solubility, narrow melting point and boiling point range, large surface tension, low viscosity, low dielectric constant, high evaporation temperature and fast evaporation speed, so it can be used as a low toxic solvent in coating industry and pharmaceutical industry.

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