Dimethyl sulfate

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Structural formula
Structural formula of dimethyl sulfate
Surname Dimethyl sulfate
other names
  • Sulfuric acid dimethyl ester
  • DMS
Molecular formula C 2 H 6 O 4 S
Brief description

colorless liquid with a sweet odor

External identifiers / databases
CAS number 77-78-1
EC number 201-058-1
ECHA InfoCard 100,000,963
PubChem 6497
Wikidata Q413421
Molar mass 126.13 g mol −1
Physical state



1.33 g cm −3

Melting point

−32 ° C

boiling point

188.5 ° C (decomposition)

Vapor pressure

0.35 h Pa (20 ° C)


poor in water (28 g l −1 at 18 ° C)

Refractive index

1.3874 (20 ° C)

safety instructions
GHS hazard labeling from  Regulation (EC) No. 1272/2008 (CLP) , expanded if necessary
06 - Toxic or very toxic 08 - Dangerous to health 05 - Corrosive


H and P phrases H: 301-314-317-330-341-350
P: 201-280-301 + 330 + 331-302 + 352-304 + 340-305 + 351 + 338-308 + 310
Authorization procedure under REACH

particularly worrying : carcinogenic ( CMR )

  • not specified because it is carcinogenic
  • Switzerland: 0.02 ml m −3 or 0.1 mg m −3
Toxicological data

205 mg kg −1 ( LD 50ratoral )

Thermodynamic properties
ΔH f 0

−735.5 kJ / mol

As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . Refractive index: Na-D line , 20 ° C

Dimethyl sulfate is a colorless, sweet-smelling, very toxic liquid. It is the dimethyl ester of sulfuric acid and is available in moderate yield from methanol and H 2 SO 4 . It is an extremely potent alkylating agent in chemical synthesis . Its toxicity is based on the alkylation of DNA and proteins .

In Europe, the largest production facility is operated by Grillo-Werke AG in the Höchst industrial park in Frankfurt .

The abbreviation DMS, which is frequently used, is ambiguous as it is also used for dimethyl sulfide , dimethyl sulfone and dimethyl sulfite. Mixing up the substances is dangerous because of their different properties.


The synthesis takes place by reacting dimethyl ether with sulfur trioxide (SO 3 ). Up until the 1980s, this was the main use of dimethyl ether, in 1998 about 15,000 t of the 50,000 t produced in Central Europe were converted into dimethyl sulfate.


The sulfate ion is a very weak nucleophile and thus an excellent leaving group in an S N reaction . This is what gives dimethyl sulfate its powerful ability to methylate . At room temperature only one methyl group reacts at first; when heated, both methyl groups can be used. The reaction with a carboxylic acid is an example of such a methylation:

Production of a carboxylic acid methyl ester


Dimethyl sulfate is used in laboratories and technology for the methylation of carboxylic acids, amines, phenols and other compounds. It is a raw material used in the manufacture of cosmetics , fabric softeners , paints , pharmaceuticals and agricultural products . In molecular biology, it was used as a reagent for the methylation of the base guanine (G), which precedes a specific strand break in sequencing according to Maxam and Gilbert .

safety instructions

Dimethyl sulfate is clearly classified as carcinogenic and suspected to be mutagenic in humans . It can diffuse quickly through intact skin . Due to its alkylating effect, dimethyl sulfate is a strong poison for the mucous membranes and lungs. The carcinogenic effect of dimethyl sulfate is based on this: The DNA is methylated and can no longer be read, the poisoned cell dies or mutates. The liver, kidneys, heart and nervous system are also attacked. Due to the sulfuric acid produced during hydrolysis , dimethyl sulfate also has a strong corrosive effect. According to Appendix II, No. 6 of the German Hazardous Substances Ordinance (GefStoffV), the substance is classified as a particularly dangerous carcinogenic substance and may only be manufactured or used in closed facilities.

Extreme caution is required when working with the substance. Since there is no warning effect (odorless, no acute irritant effect), dangerous quantities can easily be absorbed unnoticed. After a latency period of around six to twelve hours, severe burns of the airways follow. It is essential to wear special protective gloves and to work in a fume cupboard that pulls well. Any residues of dimethyl sulfate must be destroyed in a mixture of 10% monoethanolamine , 30% butyl diglycol and 60% water.

Individual evidence

  1. a b c d e f g h i j Entry on dimethyl sulfate in the GESTIS material database of the IFA , accessed on January 10, 2017(JavaScript required) .
  2. David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Physical Constants of Organic Compounds, pp. 3-210.
  3. Entry on Dimethyl sulphate in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
  4. Entry in the SVHC list of the European Chemicals Agency , accessed on July 16, 2014.
  5. Swiss Accident Insurance Fund (Suva): Limit values ​​- current MAK and BAT values (search for 77-78-1 or dimethyl sulfate ), accessed on November 2, 2015.
  6. David R. Lide (Ed.): CRC Handbook of Chemistry and Physics . 90th edition. (Internet version: 2010), CRC Press / Taylor and Francis, Boca Raton, FL, Standard Thermodynamic Properties of Chemical Substances, pp. 5-23.
  7. Grillo-Werke AG | DIMETHYL SULPHATE (DMS) . ( grillo.de [accessed November 8, 2018]).
  8. Manfred Müller, Ute Hübsch: Dimethyl Ether . In: Ullmann's Encyclopedia of Industrial Chemistry , Wiley-VCH, Weinheim 2006, doi : 10.1002 / 14356007.a08_541 .
  9. Carsten Schmuck, Bernd Engels, Tanja Schirmeister, Reinhold Fink: Chemistry for Medicine , Pearson Studies, ISBN 978-3-8273-7286-4 , p. 457.
  10. Hazardous Substances Ordinance (GefStoffV) - as of April 2017 .
  11. BG RCI - GisChem Hazardous Substance Information System Chemicals. In: www.gischem.de. Retrieved October 22, 2016 .

Web links

Safety data sheets

Safety data sheets from various manufacturers in alphabetical order for dimethyl sulfate:

Other substance information