Name | Dimethyl sulfate |
Synonyms | Dimethylsulfate Dimethyl sulfate dimethyl sulphate DIMETHYLSULFATE,REAGENT Sulfuricacid, dimethyl ester DIMETHYL SULFATE[FOR ACETAMIPRID] Dimethylsulfate (chemical production) DIMETHYL SULFATE MOLECULAR BIOLOGY*REAGE NT |
CAS | 77-78-1 |
EINECS | 201-058-1 |
InChI | InChI=1/C2H6O4S/c1-5-7(3,4)6-2/h1-2H3 |
Molecular Formula | C2H6O4S |
Molar Mass | 126.13 |
Density | 1.333g/mLat 25°C(lit.) |
Melting Point | -32 °C |
Boling Point | 188°C(lit.) |
Flash Point | 182°F |
Water Solubility | 2.8 g/100 mL (18 ºC) |
Solubility | ethanol: 0.26g/mL, clear, colorless |
Vapor Presure | 0.7 mm Hg ( 25 °C) |
Vapor Density | 4.3 (vs air) |
Appearance | Liquid |
Color | Clear colorless |
Odor | Almost odorless |
Exposure Limit | TLV/PEL-TWA skin 0.1 ppm (0.52 mg/m3 )(ACGIH, OSHA, NIOSH)IDLH 10 ppm (NIOSH). |
Merck | 13,3282 |
BRN | 635994 |
Storage Condition | 2-8°C |
Stability | Stable; combustible. Incompatible with strong oxidizing agents, strong bases including ammonia. Moisture-sensitive. |
Refractive Index | n20/D 1.386(lit.) |
Physical and Chemical Properties | Colorless oily liquid. melting point -31.75 ℃ boiling point 188.5 ℃ relative density 1.3283 refractive index 1.3874 flash point 83.3 ℃ solubility miscible with ethanol, soluble in ether, benzene, slightly soluble in water, insoluble in carbon disulfide. |
Use | Used in the manufacture of dimethyl sulfoxide, caffeine, codeine, vanillin, aminopyrine, trimethoprim and pesticide acephate |
Hazard Symbols | T+ - Very toxic |
Risk Codes | R45 - May cause cancer R25 - Toxic if swallowed R26 - Very Toxic by inhalation R34 - Causes burns R43 - May cause sensitization by skin contact R68 - Possible risk of irreversible effects |
Safety Description | S53 - Avoid exposure - obtain special instructions before use. S45 - In case of accident or if you feel unwell, seek medical advice immediately (show the label whenever possible.) S61 - Avoid release to the environment. Refer to special instructions / safety data sheets. |
UN IDs | UN 1595 6.1/PG 1 |
WGK Germany | 2 |
RTECS | WS8225000 |
FLUKA BRAND F CODES | 21 |
HS Code | 29209090 |
Hazard Class | 6.1(a) |
Packing Group | I |
Toxicity | LD50 orally in rats: 440 mg/kg (Smyth) |
colorless oily liquid. Flammable. The relative density (d20) was 1. 3283. Melting Point -31. 75 °c. Boiling point 188.5 °c. Flash point 83.3 °c. Refractive index 3874. Miscible with ethanol, soluble in ether, benzene, slightly soluble in water, insoluble in carbon disulfide.
methanol and sulfuric acid reaction into hydrogen sulfate methyl ester, followed by the reaction of dimethyl ether. Dimethyl ether is reacted with sulfur trioxide in the presence of a solvent and a catalyst to form dimethyl sulfate. The product was refined by fractional distillation under reduced pressure. Sulfur trioxide occurs from fuming sulfuric acid.
used as a methylating agent in organic synthesis to produce methyl ester, methyl ether, methylamine, etc. Is dimethyl sulfoxide, caffeine, codeine, vanillin, aminopyrine, trimethoprim and acephate and other raw materials.
(IARC) carcinogen classification | 2A (Vol. 4, Sup 7, 71) 1999 |
NIST chemical information | information provided by: webbook.nist.gov (external link) |
EPA chemical substance information | information provided by: ofmpeb.epa.gov (external link) |
Application | dimethyl sulfate can be used as a methylating reagent to synthesize dimethyl sulfoxide, anisole, metamizole, caffeine, antipyrine, methamidophos and acephate pesticide. It is similar to all strong alkylating agents, with high toxicity, skin contact or inhalation of serious hazards. The application in organic chemistry has been gradually replaced by low toxicity of dimethyl carbonate and methyl triflate. |
Introduction | dimethyl sulfate, organic compound, colorless or yellowish, slightly onion odor oily flammable liquid. Chemical formula (CH3)2SO4. Molecular weight 126.14. Relative density 1.3322(20 C/4 C). Melting Point -31.8 °c. Boiling point 188 °c/ring opening. Flash point 83.33 °c. Spontaneous ignition point 187.78. The vapor density was 4.35. The vapor pressure is 2.00kPa(15mm HG 76 degrees C). Soluble in ethanol, ether, acetone, aromatic hydrocarbons, carbon disulfide-soluble, aliphatic hydrocarbons and water. Solubility in water 2.8g/100ml. It is easily hydrolyzed into sulfuric acid and methanol at 18 °c. Slow decomposition in cold water. Flammable when exposed to heat, open flame, or oxidizing agents. |
toxicity profile | human inhaled LCLo: 97ppm/10m. Rat oral LD50: 205mg/kg; Inhalation LC50: 45mg/m3/4H. Mouse oral LD50: 140 mg/kg; Inhalation LC50: 280 mg/m3. Dimethyl sulfate is a highly toxic class, similar to the role of mustard, acute toxicity similar to phosgene, 15 times greater than chlorine. Eye, upper respiratory tract has a strong stimulating effect on the skin has a strong corrosive effect. Can cause Conjunctival Congestion, edema, corneal epithelial exfoliation, trachea, bronchial epithelial cells part of necrosis, penetrating leading to mediastinal or subcutaneous emphysema. In addition, can also damage the liver, kidney and heart muscle, skin contact can cause burns, blisters and deep necrosis. The mechanism of action is not fully understood, most scholars believe that because of the methyl nature of the material, it is hydrolyzed into methanol and sulfuric acid in the body and cause toxic effects, this has been confirmed by animal experiments and the detection of methanol in the blood and internal organs of dead cases. Ghirinshelli believes that the local effects on the eye and skin are partly due to sulfuric acid, while the systemic and nervous system effects and pulmonary edema are due to the toxic effects of the dimethyl sulfate molecule itself, because it can make certain important groups in the body caused by methylation. Dimethyl sulfate is a potential carcinogen and mutagen that can cause chromosomal aberrations. It is volatile, toxic, corrosive and harmful to the environment, and can be absorbed through the skin, mucous membranes and gastrointestinal tract. The onset of toxic symptoms may be delayed by 6-24 hours, resulting in insensitivity to the source of toxicity and further worsening of symptoms. A small amount of dimethyl sulfate leakage can be hydrolyzed with concentrated alkali solution, such as ammonia water, alkali metal hydroxide solution, etc., but the hydrolysis reaction may be very severe when a large amount of leakage. The final product of the reaction of ordinary water with dimethyl sulfate is methanol and sulfuric acid, the reaction is slow and the product is harmful to the environment, so the leakage of dimethyl sulfate cannot be treated with water. |
carcinogenicity | dialkyl sulfate compounds are known carcinogenic teratogenic agents, by alkylating nucleic acid salts and causing genetic genetic damage and chromosomal mutations, the European Union listed dimethyl sulfate (DMS) and diethyl sulfate (DES) in the eighth batch of authorized substances (SVHC) in December 2012. The candidate list, the International Centre for Research on Cancer (IARC), has also classified dimethyl sulfate as a Class 2A carcinogen. |
preparation of 3,4,5 trimethoxy toluene | in a 250ml three-necked flask, add 17.0G of 2, 6-dimethoxy-4-methylphenol, 50ml toluene, 400g polyethylene glycol-, mix well, then add 5.0g sodium hydroxide, slowly drop 12.5ml dimethyl sulfate with stirring, refluxed at 90 ℃ for 1H, then refluxed with a small amount of water for 0.5H and cooled, then washed with sodium hydroxide solution and water for 3 times respectively. The organic layer was dried over anhydrous magnesium sulfate, and the solvent was removed after drying to obtain a pale yellow liquid, the fractions at 135-137 °c (pressure 3kPa) were collected to obtain 3,4,5-trimethoxy toluene. Yield 96%. |
quenching method | with stirring, add Dropwise to dilute NaOH or aqueous ammonia, after neutralization, pour the corresponding waste liquid bucket in the landing fume hood. Add alkaline hydrolysis into methanol and sulfuric acid, greatly reduce the toxicity. |
Use | used as a methylating agent in the manufacture of dimethyl sulfoxide, caffeine, vanillin, aminopyrine, trimethoprim and acephate are used as reagents for the determination of coal tar and methyl substituents in organic synthesis, also used as a solvent for aromatic hydrocarbons used in the manufacture of dimethyl sulfoxide, caffeine, codeine, vanillin, aminopyrine, trimethoprim and pesticide acephate dimethyl sulfate is an important organic intermediate, in the production of pesticides mainly as a methylation reagent, introducing methyl groups in the molecule, a wide range of uses, such as fungicide, formazan, Tian An, insecticide of methamidophos, acephate, Amine methanethiophos, beta-thiophos, pirimicarb, herbicide grass net, isopropyl net, grass net, wild green, paraquat, oxazinone, dicamba, pemirosulfuron, etc. dimethyl sulfate is a widely used methylating agent in the organic synthesis of pesticides, dyes, pharmaceuticals, perfume industry and so on. For the manufacture of methyl ester, methyl ether, methyl amine, etc. It is the raw material of dimethyl sulfoxide, caffeine, codeine, metamizole, aminopyrine, trimethoprim, vanillin and acephate. |
production method | There are many synthesis methods of dimethyl sulfate, such as sodium salt method, direct reaction of anhydrous sulfuric acid with methanol, dimethyl ether and sulfur trioxide synthesis, chlorosulfonic acid synthesis, hydrogen sulfate methyl ester method. However, in addition to the synthesis of dimethyl ether and sulfur trioxide, there are problems such as low product yield, large consumption of raw materials and serious corrosion of equipment. In the industry, dimethyl ether and sulfur trioxide are mainly used to produce dimethyl sulfate. First, dimethyl ether was obtained by dehydration of methanol. Then 25% fuming sulfuric acid was heated and distilled out of sulfur trioxide gas, and dimethyl sulfate was sprayed and absorbed. Dimethyl sulfate, which has absorbed sulfur trioxide, reacts with dimethyl ether gas in a synthesis tower to form dimethyl sulfate. The purity of industrial dimethyl sulfate is greater than or equal to 98%. Raw material consumption quota: methanol 550kg/t, fuming sulfuric acid (25%)3000kg/t. The preparation method is to dehydrate methanol with sulfuric acid to produce methyl bisulfate at a reaction temperature of 40-60 ℃, and then the methyl bisulfate reacts with methanol at 120-145 ℃ to obtain dimethyl ether, at the same time, dimethyl sulfate is used to absorb sulfur trioxide to near saturation at 40~60 ℃ as mother liquor, and finally sulfur trioxide and dimethyl ether in mother liquor are reacted at 60~80 ℃ to obtain crude product, the product was obtained by distillation under reduced pressure. H2SO4+CH3OH→CH3HSO4+H2OCH3HSO4+CH3OH→CH3OCH3+H2SO4SO3+(CH3)2SO4→(CH3)2SO4·SO3CH3OCH3+(CH3)2SO4·SO3→2(CH3)2SO4 |
category | toxic substances |
toxicity grade | high toxicity |
Acute toxicity | oral-rat LD50: 205 mg/kg; Oral-mouse LD50: 140 mg/kg |
stimulation data | Skin-rabbits 10 mg/24 h severe; eye-rabbit 100 mg/4 S severe |
explosive hazard characteristics | explosive when mixed with air |
flammability hazard characteristics | flammable in case of open flame and high heat; Toxic sulfur oxide smoke generated by heating |
storage and transportation characteristics | The warehouse is ventilated and dried at low temperature, separate storage of food additives |
fire extinguishing agent | water, foam, carbon dioxide |
Occupational Standard | TLV-TWA: 0.05 mg/m3; Tel: 0.1 mg/m3 (skin) |
spontaneous combustion temperature | 495°C |
toxic substance data | information provided by: pubchem.ncbi.nlm.nih.gov (external link) |
immediate life-and health-threatening concentration | 7 ppm |