2165. Chlorosulfonic Acid

Nomenclature

CAS number: 7790-94-5
Sulfuric chlorohydrin; chlorosulfuric acid.
ClHO3S; mol wt 116.52.
Cl 30.43%, H 0.87%, O 41.19%, S 27.52%.
SO2(OH)Cl.

Description and references

Prepd by the reaction of HCl gas with SO3: Simon, Kratsch, Z. Anorg. Allg. Chem. 242, 369 (1939); Briggs, US 1442335 (1922 to General Chem.). Purification: Kaplar, Shechter, Inorg. Synth. 4, 52 (1953). Review: H. O. Burrus in Kirk-Othmer Encyclopedia of Chemical Technology vol. 5 (Wiley-Interscience, New York, 3rd ed., 1979) pp 873-880.

Properties

Colorless or slightly yellow, very corrosive liquid, causes severe burns; fumes in air; pungent odor. d2020 1.76-1.77; d40 1.784; d420 1.753. mp -80°. bp755 151-152°; bp19 74-75°; bp2-4 60-64°. nD14 1.437. On dropping into water dec with explosive violence. Corrosive, poisonous. Keep tightly closed. When used for the prepn of sulfate esters, the common solvent is pyridine. Other solvents are liquid sulfur dioxide and dichloroethane.

Caution

Highly irritating and corrosive to eyes, skin, mucous membranes.

Use

Manuf sulfone compds, saccharin. As chlorosulfonating and condensing agent in organic syntheses.