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Names | |
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Preferred IUPAC name Dimethyl carbonate | |
Other names DMC Methyl carbonate, di- | |
Identifiers | |
3D model (JSmol) | |
ChEBI | |
ChemSpider | |
ECHA InfoCard | 100.009.527 |
PubChem CID | |
UNII | |
CompTox Dashboard (EPA) | |
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Properties | |
C3H6O3 | |
Molar mass | 90.078 g·mol−1 |
Appearance | colorless liquid |
Density | 1.069-1.073 g/mL |
Melting point | 2 to 4 °C (36 to 39 °F; 275 to 277 K) |
Boiling point | 90 °C (194 °F; 363 K) |
13.9 g/100 mL | |
Hazards | |
Occupational safety and health (OHS/OSH): | |
Main hazards | Flammable |
Flash point | 17 °C (63 °F; 290 K) |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Dimethyl carbonate (DMC) is an organic compound with the formula OC(OCH3)2. It is a colourless, flammable liquid. It is classified as a carbonate ester. This compound has found use as a methylating agent and as a co-solvent in lithium-ion batteries. [1] Notably, dimethyl carbonate is a weak methylating agent, and is not considered as a carcinogen. [2] Instead, dimethyl carbonate is often considered to be a green reagent, [3] [4] and it is exempt from the restrictions placed on most volatile organic compounds (VOCs) in the United States. [5]
World production in 1997 was estimated at 1000 barrels a day. [6] Production of dimethyl carbonate worldwide is limited to Asia, the Middle East, and Europe.
Dimethyl carbonate is traditionally prepared by the reaction of phosgene and methanol. Methyl chloroformate is produced as an intermediate:
This synthesis route has been largely replaced by oxidative carbonylation. In this process, carbon monoxide and an oxidizer provide the equivalent of CO2+: [7] [8]
It can also be produced industrially by a transesterification of ethylene carbonate or propylene carbonate and methanol, which also affords respectively ethylene glycol or propylene glycol. This route is complicated by the methanol-DMC azeotrope, which requires azeotropic distillation or other techniques. [9]
Dimethyl carbonate methylates anilines, carboxylic acids, and phenols, albeit usually slowly. [10] [11] [12] Sometimes these reactions require the use of an autoclave.
Dimethyl carbonate's main benefit over other methylating reagents such as iodomethane and dimethyl sulfate is its low toxicity. Additionally, it is biodegradable. [7] Unfortunately, it is a relatively weak methylating agent compared to these traditional reagents.
In the US, dimethyl carbonate was exempted under the definition of volatile organic compounds (VOCs) by the U.S. EPA in 2009. [13] Due to its classification as VOC exempt, dimethyl carbonate has grown in popularity and applications as a replacement for methyl ethyl ketone (MEK) and parachlorobenzotrifluoride, as well as tert-butyl acetate until it too was exempted. [14] Dimethyl carbonate has an ester- or alcohol-like odor, which is more favorable to users than most hydrocarbon solvents it replaces. Dimethyl carbonate has an evaporation rate of 3.22 (butyl acetate = 1.0), which slightly slower than MEK (3.8) and ethyl acetate (4.1), and faster than toluene (2.0) and isopropanol (1.7). Dimethyl carbonate has solubility profile similar to common glycol ethers, meaning dimethyl carbonate can dissolve most common coating resins except perhaps rubber based resins. Hildebrand solubility parameter is 20.3 MPa and Hansen solubility parameters are: dispersion = 15.5, polar = 3.9, H bonding = 9.7. [15] Dimethyl carbonate is partially soluble in water up to 13%, however it is hydrolyzed in water-based systems over time to methanol and CO2 unless properly buffered. Dimethyl carbonate can freeze at same temperatures as water, it can be thawed out with no loss of properties to itself or coatings based on dimethyl carbonate.
A large captive use of dimethyl carbonate is for the production of diphenyl carbonate through transesterification with phenol. Diphenyl carbonate is a widely used raw material for the synthesis of bisphenol-A-polycarbonate in a melt polycondensation process, [16] the resulting product being recyclable by reversing the process and transesterifying the polycarbonate with phenol to yield diphenyl carbonate and bisphenol A. [17]
There is also interest in using this compound as a fuel oxygenate additive. [6]
Similar to ethylene carbonate, dimethyl carbonate forms an electronically-insulating Li+-conducting film at negative electrode potentials. However, the film in dry DMC solutions is not as effective in passivating the negative electrode as the film in wet solutions. [18] For this reason dimethyl carbonate is rarely used in lithium batteries without a co-solvent. [19]
DMC is a flammable liquid with a flash point of 17 °C (63 °F), which limits its use in consumer and indoor applications. DMC is still safer than acetone, methyl acetate and methyl ethyl ketone from a flammability point of view. The National Center for Sustainable Transportation recommends limiting exposure by inhalation to less than 100 ppm over an 8-hour work day, which is similar to that of a number of common industrial solvents (toluene, methyl ethyl ketone). [20] Workers should wear protective organic vapor respirators when using DMC indoors or in other conditions where concentrations exceed the REL. DMC is metabolized by the body to methanol and carbon dioxide, so accidental ingestion should be treated in the same manner as methanol poisoning.[ citation needed ]
In chemistry, an alcohol is a type of organic compound that carries at least one hydroxyl functional group bound to a saturated carbon atom. Alcohols range from the simple, like methanol and ethanol, to complex, like sucrose and cholesterol. The presence of an OH group strongly modifies the properties of hydrocarbons, conferring hydrophilic (water-loving) properties. The OH group provides a site at which many reactions can occur.
In chemistry, an ester is a compound derived from an acid in which the hydrogen atom (H) of at least one acidic hydroxyl group of that acid is replaced by an organyl group. Analogues derived from oxygen replaced by other chalcogens belong to the ester category as well. According to some authors, organyl derivatives of acidic hydrogen of other acids are esters as well, but not according to the IUPAC.
Butanone, also known as methyl ethyl ketone (MEK) or ethyl methyl ketone, is an organic compound with the formula CH3C(O)CH2CH3. This colorless liquid ketone has a sharp, sweet odor reminiscent of acetone. It is produced industrially on a large scale, but occurs in nature only in trace amounts. It is partially soluble in water, and is commonly used as an industrial solvent. It is an isomer of another solvent, tetrahydrofuran.
Alkylation is a chemical reaction that entails transfer of an alkyl group. The alkyl group may be transferred as an alkyl carbocation, a free radical, a carbanion, or a carbene. Alkylating agents are reagents for effecting alkylation. Alkyl groups can also be removed in a process known as dealkylation. Alkylating agents are often classified according to their nucleophilic or electrophilic character. In oil refining contexts, alkylation refers to a particular alkylation of isobutane with olefins. For upgrading of petroleum, alkylation produces a premium blending stock for gasoline. In medicine, alkylation of DNA is used in chemotherapy to damage the DNA of cancer cells. Alkylation is accomplished with the class of drugs called alkylating antineoplastic agents.
Methyl acetate, also known as MeOAc, acetic acid methyl ester or methyl ethanoate, is a carboxylate ester with the formula CH3COOCH3. It is a flammable liquid with a characteristically pleasant smell reminiscent of some glues and nail polish removers. Methyl acetate is occasionally used as a solvent, being weakly polar and lipophilic, but its close relative ethyl acetate is a more common solvent being less toxic and less soluble in water. Methyl acetate has a solubility of 25% in water at room temperature. At elevated temperature its solubility in water is much higher. Methyl acetate is not stable in the presence of strong aqueous bases or aqueous acids. Methyl acetate is not considered a VOC in the USA.
Dimethyl sulfate (DMS) is a chemical compound with formula (CH3O)2SO2. As the diester of methanol and sulfuric acid, its formula is often written as (CH3)2SO4 or Me2SO4, where CH3 or Me is methyl. Me2SO4 is mainly used as a methylating agent in organic synthesis.
In organic chemistry, a carbonate ester is an ester of carbonic acid. This functional group consists of a carbonyl group flanked by two alkoxy groups. The general structure of these carbonates is R−O−C(=O)−O−R' and they are related to esters, ethers and also to the inorganic carbonates.
The National Pollutant Inventory (NPI) is a database of Australian pollution emissions managed by the Australian Commonwealth, State and Territory Governments. A condensed version of the information collected is available to the public via the Department’s website.
Glycol ethers are a class of chemical compounds consisting of alkyl ethers that are based on glycols such as ethylene glycol or propylene glycol. They are commonly used as solvents in paints and cleaners. They have good solvent properties while having higher boiling points than the lower-molecular-weight ethers and alcohols.
Methyl carbamate (also called methylurethane, or urethylane) is an organic compound and the simplest ester of carbamic acid (H2NCO2H). It is a colourless solid.
This is the list of extremely hazardous substances defined in Section 302 of the U.S. Emergency Planning and Community Right-to-Know Act. The list can be found as an appendix to 40 CFR 355. Updates as of 2006 can be seen on the Federal Register, 71 FR 47121.
Sodium methoxide is the simplest sodium alkoxide. With the formula CH3ONa, it is a white solid, which is formed by the deprotonation of methanol. It is a widely used reagent in industry and the laboratory. It is also a dangerously caustic base.
Propylene carbonate (often abbreviated PC) is an organic compound with the formula C4H6O3. It is a cyclic carbonate ester derived from propylene glycol. This colorless and odorless liquid is useful as a polar, aprotic solvent. Propylene carbonate is chiral, but is used as the racemic mixture in most contexts.
Methyl trifluoromethanesulfonate, also commonly called methyl triflate and abbreviated MeOTf, is the organic compound with the formula CF3SO2OCH3. It is a colourless liquid which finds use in organic chemistry as a powerful methylating agent. The compound is closely related to methyl fluorosulfonate (FSO2OCH3). Although there has yet to be a reported human fatality, several cases were reported for methyl fluorosulfonate (LC50 (rat, 1 h) = 5 ppm), and methyl triflate is expected to have similar toxicity based on available evidence.
Ethylene carbonate (sometimes abbreviated EC) is the organic compound with the formula (CH2O)2CO. It is classified as the cyclic carbonate ester of ethylene glycol and carbonic acid. At room temperature (25 °C) ethylene carbonate is a transparent crystalline solid, practically odorless and colorless, and somewhat soluble in water. In the liquid state (m.p. 34-37 °C) it is a colorless odorless liquid.
Dimethyl oxalate is an organic compound with the formula (CO2CH3)2 or (CH3)2C2O4. It is the dimethyl ester of oxalic acid. Dimethyl oxalate is a colorless or white solid that is soluble in water.
Diphenyl carbonate is the organic compound with the formula (C6H5O)2CO. It is classified as an acyclic carbonate ester. It is a colorless solid. It is both a monomer in combination with bisphenol A in the production of polycarbonate polymers and a product of the decomposition of polycarbonates.
VOC exempt solvents are organic compounds that are exempt from restrictions placed on most volatile organic compounds (VOCs) in the United States. This class of solvent currently includes acetone, dimethyl carbonate, methyl acetate, parachlorobenzotrifluoride, tert-Butyl acetate, and propylene carbonate. The definition is often that they do not contribute to ozone or ozone depletion.
Glycerol-1,2-carbonate is formally the cyclic ester of carbonic acid with glycerol and has aroused great interest as a possible product from the "waste materials" carbon dioxide CO2 and glycerol (especially from biodiesel production) with a wide range of applications.
Green solvents are environmentally friendly chemical solvents that are used as a part of green chemistry. They came to prominence in 2015, when the UN defined a new sustainability-focused development plan based on 17 sustainable development goals, recognizing the need for green chemistry and green solvents for a more sustainable future. Green solvents are developed as more environmentally friendly solvents, derived from the processing of agricultural crops or otherwise sustainable methods as alternatives to petrochemical solvents.