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Dimethyl sulfate

Dimethyl sulfate
Dimethylsulfate.png
Dimethyl sulfate -Molecule-3D-balls-by-AHRLS-2012.png
Names
Other names
Sulfuric acid dimethyl ester; Me2SO4; DMSO4; Dimethyl ester of sulfuric acid, Methyl sulfate
Identifiers
77-78-1 YesY
3D model (Jmol) Interactive image
ChEBI CHEBI:59050 YesY
ChEMBL ChEMBL162150 YesY
ChemSpider 6252 YesY
ECHA InfoCard 100.000.963
KEGG C19177 YesY
PubChem 6497
Properties
C2H6O4S
Molar mass 126.13 g/mol
Appearance Colorless, oily liquid
Odor faint, onion-like
Density 1.33 g/ml, liquid
Melting point −32 °C (−26 °F; 241 K)
Boiling point 188 °C (370 °F; 461 K) (decomposes)
Reacts
Solubility Methanol, dichloromethane, acetone
Vapor pressure 0.1 mmHg (20°C)
-62.2·10−6 cm3/mol
Hazards
Main hazards Extremely toxic, contact hazard, inhalation hazard, corrosive, environmental hazard, carcinogenic, mutagenic
R-phrases R45, R25, R26, R34,
R43, R68
S-phrases S53, S45, S30, S60, S61
NFPA 704
Flammability code 2: Must be moderately heated or exposed to relatively high ambient temperature before ignition can occur. Flash point between 38 and 93 °C (100 and 200 °F). E.g., diesel fuel Health code 4: Very short exposure could cause death or major residual injury. E.g., VX gas Reactivity code 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g., calcium Special hazards (white): no codeNFPA 704 four-colored diamond
Flash point 83 °C; 182 °F; 356 K
Lethal dose or concentration (LD, LC):
8.6 ppm (rat, 4 hr)
75 ppm (guinea pig, 20 min)
53 ppm (mouse)
32 ppm (guinea pig, 1 hr)
97 ppm (human, 10 min)
US health exposure limits (NIOSH):
PEL (Permissible)
 TWA 1 ppm (5 mg/m3) [skin]
REL (Recommended)
 Ca TWA 0.1 ppm (0.5 mg/m3) [skin]
IDLH (Immediate danger)
 Ca [7 ppm]
Related compounds
Related compounds
 Diethyl sulfate, methyl triflate, dimethyl carbonate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
YesY  (what is YesYN ?)
Infobox references

Dimethyl sulfate 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 even Me2SO4, where CH3 or Me is methyl. Me2SO4 is mainly used as a methylating agent in organic synthesis.

Under standard conditions, Me2SO4 is a colourless oily liquid with a slight onion-like odour (although smelling it would represent significant exposure). Like all strong alkylating agents, Me2SO4 is extremely toxic. Its use as a laboratory reagent has been superseded to some extent by methyl triflate, CF3SO3CH3, the methyl ester of trifluoromethanesulfonic acid.

Dimethyl sulfate was first discovered in the early 19th century in an impure form. P Claesson later extensively studied its preparation. It was used in chemical warfare in WW I.

Dimethyl sulfate can be synthesized in the laboratory by many different syntheses, the simplest being the esterification of sulfuric acid with methanol:

Another possible synthesis involves distillation of methyl hydrogen sulfate:

Methyl nitrite and methyl chlorosulfonate also result in dimethyl sulfate:

Me2SO4 has been produced commercially since the 1920s. A common process is the continuous reaction of dimethyl ether with sulfur trioxide.


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Wikipedia

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