3726. Ethanethiol

Nomenclature

CAS number: 75-08-1
Ethyl mercaptan; mercaptoethane; ethyl sulfhydrate; thioethyl alcohol.
C2H6S; mol wt 62.13.
C 38.66%, H 9.73%, S 51.61%.
CH3CH2SH.

Description and references

Found in urine of rabbits after ingestion of cabbage. Is formed in vinous fermentation. Occurs in illuminating gas, in “sour” natural gas of W. Texas; in petroleum distillates from which it may be separated by chemical or physical methods: Thompson et al., Anal. Chem. 27, 175 (1955). Prepn from sodium ethylsulfate and KSH: Klason, Ber. 20, 3407 (1887); catalytically from ethanol and hydrogen sulfide: Kramer, Reid, J. Am. Chem. Soc. 43, 880 (1921). Review on occurrence, prepn, properties and reactions: E. Emmet Reid, Organic Chemistry of Bivalent Sulfur vol. I, 15-261 (Chemical Publishing Co., New York, 1958).

Properties

Liquid; penetrating leek-like odor: minimum detectable concn = 1 part in 50 billion parts of air. d40 0.8617; d425 0.83147. bp 34.7-35.04°; bp400 17.7°; bp200 1.5°; bp100 -13.0°; bp10 -50.2°; bp1 -76.1°. mp -147.97 to -144.4°. nD20 1.431; nD25 1.420. Crit temp 225.5°. Crit pressure 54.2 atm. Explosive limits 2.8 and 18.2% by vol of vapor. Min ignition temp in air 299°, in oxygen 261°. Entropy at 25°: 70.77 cal/deg/mole. Heat capacity at 25°: 17.37 cal/deg/mole. Surface tension at 2°: 23.63 dynes/cm; at 16.7°: 21.62 dynes/cm. Viscosity at 20°: 0.003155 g/cm sec. Azeotrope with n-pentane (51% ethanethiol) bp 30.46°; with ether (40% ethanethiol) bp 31.50°. Soly in water at 20°: 6.76 g/l or 0.112 moles/l. Sol in alcohol, ether. Keep tightly closed and in a cool place.

Derivative

Octadecahydrate.

Properties

Needles. Practically insol in water, ethanethiol.

Derivative

Sodium salt.
C2H5NaS; mol wt 84.12.
C 28.56%, H 5.99%, Na 27.33%, S 38.12%.

Properties

Hydrolyzes instantly in water.

Caution

Potential symptoms of overexposure to ethanethiol are headache, nausea and irritation of mucous membranes. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 140.

Use

Odorant for natural gas; intermediate and starting material in manuf of plastics, insecticides, antioxidants.