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Systematic name Thiophosgene
Other names Thiocarbonylchloride
Molecular formula CSCl2
Molar mass 114.98 g/mol
Appearance yellow liquid
CAS number [463-71-8]
Density and phase 1.50 g/cm3
Solubility in water decomp.
Other solvents polar organic solvents
rxn with amines, ROH
Melting point  ? °C (? K)
Boiling point 70-75 °C (? K)
Viscosity  ? cP at ? °C
Molecular shape planar, sp2, C2v
Dipole moment  ? D
MSDS External MSDS
Main hazards highly toxic
NFPA 704
R/S statement R: 22-23-36/37/38
S: 7-9-36/37-45
RTECS number XN2450000
Supplementary data page
Structure and
n, 1.548
Phase behaviour
Solid, liquid, gas
Spectral data UV, IR, NMR, MS
Related compounds
Related compounds COCl2


Except where noted otherwise, data are given for
materials in their standard state (at 25 °C, 100 kPa)
Infobox disclaimer and references

Thiophosgene is a yellow liquid with the formula CSCl2. This compound has a trigonal planar geometry. It possesses two reactive C-Cl bonds that allow this reagent to be used in diverse procedures related to organic synthesis.


Synthesis of CSCl2

CSCl2 is prepared in a two-step process from carbon disulfide. In the first step, carbon disulfide is chlorinated to give trichloromethanesulfenyl chloride, CCl3SCl:

CS2 + 3 Cl2 → CCl3SCl + S2Cl2

The chlorination must be controlled as excess chlorine converts trichloromethanesulfenyl chloride into carbon tetrachloride. Steam distillation separates the trichloromethanesulfenyl chloride, a rare sulfenyl chloride, and hydrolyzes the sulfur monochloride. Reduction of trichloromethanesulfenyl chloride produces thiophosgene:

CCl3SCl + M → CSCl2 + MCl2

Typically, tin is used for the reducing agent M.

Uses of CSCl2

CSCl2 is mainly used to prepare compounds with the connectivity CSX2 where X = OR, NHR. Such reactions proceed via intermediate such as CSClX. Under certain conditions, one can convert primary amines into isothiocyanates. CSCl2 also serves as a dienophile to give, after reduction 5-thiacyclohexene derivatives.

Safety considerations

CSCl2 is considered highly toxic.


  • Dyson, G. M. "Thiophosgene" Organic Syntheses, Coll. Vol. 1, p.506; Vol. 6, p.86.
  • Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN 0-12-352651-5.
  • Sharma, S. "Thiophosgene in Organic Synthesis" Synthesis, 1978, pages 804-820.
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Thiophosgene". A list of authors is available in Wikipedia.
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