Dimethyl sulfate #CAS77-78-1
Dimethyl sulfate #CAS77-78-1
Dimethyl sulfate (chemical formula: (CH3O)2SO2) is an odorless, corrosive, oily liquid which can release toxic fumes during heating. It can be synthesized through the esterification of sulfuric acid with methanol, and alternatively by the distillation of methyl hydrogen sulfate.In industry, dimethyl sulfate is used as a methylating agent for the manufacture of many organic chemicals. It can be used for methylation of phenols, amines, and thiol. Moreover, it can be used for base sequencing and DNA chain cleavage since it can rupture the imidazole rings present in guanine. It can also be used for protein-DNA interaction analysis. However, its vapor is toxic to eyes and lungs, can do harm to our body. It is a potential carcinogen based on known experimental data.
Application of Dimethyl sulfate
Dimethyl sulphate has been used since the beginning of the century as a methylating agent in the preparation of organic chemical products and colouring agents, in the perfume industry, and in other processes. It is a colourless or yellowish liquid of oily consistency which vaporizes at 50℃. and has a slight piquant smell. Both the liquid and the vapour are vesicants and by virtue of this property may be used in warfare.Dimethyl sulfate is a strong alkylating agent and might also react with the carboxylic acid substrate, further reducing the DMS concentration in the mixture. It is used as a methylating agent in themanufacture of many organic compounds,such as, phenols and thiols. Also, it is used inthe manufacture of dyes and perfumes, andas an intermediate for quaternary ammoniumsalts. It was used in the past as a militarypoison.
| Dimethyl sulfate Chemical Properties |
| Melting point | -32 °C |
| Boiling point | 188 °C(lit.) |
| density | 1.333 g/mL at 25 °C(lit.) |
| vapor density | 4.3 (vs air) |
| vapor pressure | 0.7 mm Hg ( 25 °C) |
| refractive index | n |
| Fp | 182 °F |
| storage temp. | 2-8°C |
| solubility | ethanol: 0.26 g/mL, clear, colorless |
| form | Liquid |
| color | Clear colorless |
| Odor | Almost odorless |
| explosive limit | 3.6-23.2% (v/v) |
| Water Solubility | 2.8 g/100 mL (18 ºC) |
| Merck | 13,3282 |
| BRN | 635994 |
| Henry's Law Constant | 6.9×100 mol/(m3Pa) at 25℃, Hilal et al. (2008) |
| Exposure limits | ACGIH:TLV-TWA 0.1 ppm (0.5 mg/m3) OSHA:PEL-TWA 1 ppm (5 mg/m3) NIOSH:REL-TWA 0.1 ppm |
| Dielectric constant | 55.0（20℃） |
| Stability: | Stable; combustible. Incompatible with strong oxidizing agents, strong bases including ammonia. Moisture-sensitive. |
| InChI | 1S/C2H6O4S/c1-5-7(3,4)6-2/h1-2H3 |
| InChIKey | VAYGXNSJCAHWJZ-UHFFFAOYSA-N |
| SMILES | COS(=O)(=O)OC |
| CAS DataBase Reference | 77-78-1(CAS DataBase Reference) |
| IARC | 2A (Vol. 4, Sup 7, 71) 1999 |
| NIST Chemistry Reference | Sulfuric acid, dimethyl ester(77-78-1) |
| EPA Substance Registry System | Dimethyl sulfate (77-78-1) |
| Safety Information |
| Hazard Codes | T+ |
| Risk Statements | 45-25-26-34-43-68 |
| Safety Statements | 53-45-61 |
| OEB | C |
| OEL | TWA: 0.1 ppm (0.5 mg/m3) [skin] |
| RIDADR | UN 1595 |
| WGK Germany | 2 |
| RTECS | WS8225000 |
| F | 21 |
| Autoignition Temperature | 495 °C |
| TSCA | TSCA listed |
| HazardClass | 6.1 |
| PackingGroup | I |
| HS Code | 29209090 |
| Storage Class | 6.1A - Combustible acute toxic Cat. 1 and 2 very toxic hazardous materials |
| Hazard Classifications | Acute Tox. 2 Inhalation Acute Tox. 3 Oral Carc. 1B Eye Dam. 1 Muta. 2 Skin Corr. 1B Skin Sens. 1 |
| Hazardous Substances Data | 77-78-1(Hazardous Substances Data) |
| Toxicity | LD50 orally in rats: 440 mg/kg (Smyth) |
| IDLA | 7 ppm |
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