Chlorosulfonyl isocyanate

Chlorosulfonyl isocyanate
Names
	IUPAC name Chlorosulfonyl isocyanate
	Other names N-Carbonylsulfamyl chloride; Chloropyrosulfonyl isocyanate; Sulfuryl chloride isocyanate
Identifiers
CAS Number	1189-71-5 ;
3D model (JSmol)	Interactive image;
ChemSpider	64080 ;
ECHA InfoCard	100.013.378
EC Number	214-715-2;
PubChem CID	70918;
UNII	2903Y990SM ;
CompTox Dashboard (EPA)	DTXSID0061585 ;
	InChI InChI=1S/CClNO3S/c2-7(5,6)3-1-4 Key: WRJWRGBVPUUDLA-UHFFFAOYSA-N ; InChI=1/CClNO3S/c2-7(5,6)3-1-4 Key: WRJWRGBVPUUDLA-UHFFFAOYAX;
	SMILES ClS(=O)(=O)N=C=O;
Properties
Chemical formula	CNClO3S
Molar mass	141.53 g/mol
Appearance	colorless liquid
Density	1.626 g/cm3
Melting point	−44 °C (−47 °F; 229 K)
Boiling point	107 °C (225 °F; 380 K)
Solubility in water	decomposition
Solubility in other solvents	Chlorocarbons; MeCN
Refractive index (nD)	1.447
Structure
Molecular shape	tetrahedral at S
Hazards
	Occupational safety and health (OHS/OSH):
Main hazards	toxic, corrosive, flammable, ; reacts violently with water
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H302, H312, H314, H330, H332, H334
Precautionary statements	P260, P261, P264, P270, P271, P280, P284, P285, P301+P312, P301+P330+P331, P302+P352, P303+P361+P353, P304+P312, P304+P340, P304+P341, P305+P351+P338, P310, P312, P320, P321, P322, P330, P342+P311, P363, P403+P233, P405, P501
NFPA 704 (fire diamond)	3 1 2 W
Safety data sheet (SDS)	"External MSDS"
Related compounds
Related compounds	Thionyl chloride; Cyanogen bromide; Phosphoryl chloride
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Chlorosulfonyl isocyanate is the chemical compound ClSO₂NCO, known as CSI. This compound is a versatile reagent in organic synthesis.

Preparation, structure, handling

CSI is prepared by treating cyanogen chloride with sulfur trioxide, the product being distilled directly from the reaction mixture.^[1]

SO₃ + ClCN → ClSO₂NCO

In this transformation, both the carbon and the nitrogen termini of CN are functionalized.

The structure of CSI is represented as ClS(O)₂-N=C=O. It consists of two electron-withdrawing components, the chlorosulfonyl group (SO₂Cl) and the isocyanate group (-N=C=O). Because of its resulting electrophilicity, the use of CSI in chemical synthesis requires relatively inert solvents such as chlorocarbons, acetonitrile, and ethers.^[2]

Uses

The molecule has two electrophilic sites, the carbon and the S(VI) center.^[3]

CSI has been employed for the preparation of β-lactams,^[4] some of which are medicinally important. Thus, alkenes undergo a [2+2]-cycloaddition to give the sulfonamide. The SO₂Cl group can be removed simply by hydrolysis, leaving the secondary amide.^[5] Other reactions of CSI:

Cycloaddition to alkynes to give 1,2,3-oxathiazine-2,2-dioxide-6-chlorides.
Conversion of primary alcohols to carbamates.^[6]
Conversion of carboxylic acids and the acid chlorides into nitriles.
Preparation of N,N-disubstituted sulfamides, R₂NSO₂NH₂
Preparation of Burgess reagent

Safety considerations

CSI is toxic, corrosive and reacts violently with water.

References

^ Graf, R. "Chlorosulfonyl Isocyanate" Organic Syntheses, Collected Volume 5, pages 226ff.
^ Miller, M. J.; Ghosh, M.; Guzzo, P. R.; Vogt, P. F.; Hu, J.; Filzen, G. F.; Geyer, A. G. "Chlorosulfonyl Isocyanate" in "Encyclopedia of Reagents for Organic Synthesis" 2005 John Wiley & Sons: New York.
^ D. N. Dhar, K. S. K. Murthy "Recent Advances in the Chemistry of Chlorosulfonyl Isocyanate" Synthesis 1986; pages 437-449.
^ Kaur, Rajneesh; Singh, Raman; Kumar, Antresh; Kaur, Satvinder; Priyadarshi, Nitesh; Singhal, Nitin Kumar; Singh, Kuldeep (June 2020). "1,2,3-Triazole β-lactam conjugates as antimicrobial agents". Heliyon. 6 (6): e04241. Bibcode:2020Heliy...604241K. doi:10.1016/j.heliyon.2020.e04241. PMC 7327255. PMID 32637684.
^ Cremlyn, R. J. “An Introduction to Organosulfur Chemistry” John Wiley and Sons: Chichester (1996). ISBN 0-471-95512-4
^ Burgess, E. M.; Penton, Jr., H. R.; Taylor, E. A.; Williams, W. M. "Conversion of Primary Alcohols to Urethanes via the Inner Salt of Triethylammonium Hydroxide: Methyl (Carboxylsulfamoyl) Triethylammonium Hydroxide Methyl n-Hexylcarbamate" Organic Syntheses, Coll. Vol. 6, p.788

[1] Graf, R. "Chlorosulfonyl Isocyanate" Organic Syntheses, Collected Volume 5, pages 226ff.

[2] Miller, M. J.; Ghosh, M.; Guzzo, P. R.; Vogt, P. F.; Hu, J.; Filzen, G. F.; Geyer, A. G. "Chlorosulfonyl Isocyanate" in "Encyclopedia of Reagents for Organic Synthesis" 2005 John Wiley & Sons: New York.

[3] D. N. Dhar, K. S. K. Murthy "Recent Advances in the Chemistry of Chlorosulfonyl Isocyanate" Synthesis 1986; pages 437-449.

[4] Kaur, Rajneesh; Singh, Raman; Kumar, Antresh; Kaur, Satvinder; Priyadarshi, Nitesh; Singhal, Nitin Kumar; Singh, Kuldeep (June 2020). "1,2,3-Triazole β-lactam conjugates as antimicrobial agents". Heliyon. 6 (6): e04241. Bibcode:2020Heliy...604241K. doi:10.1016/j.heliyon.2020.e04241. PMC 7327255. PMID 32637684.

[5] Cremlyn, R. J. “An Introduction to Organosulfur Chemistry” John Wiley and Sons: Chichester (1996). ISBN 0-471-95512-4

[6] Burgess, E. M.; Penton, Jr., H. R.; Taylor, E. A.; Williams, W. M. "Conversion of Primary Alcohols to Urethanes via the Inner Salt of Triethylammonium Hydroxide: Methyl (Carboxylsulfamoyl) Triethylammonium Hydroxide Methyl n-Hexylcarbamate" Organic Syntheses, Coll. Vol. 6, p.788

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v t e Inorganic compounds of carbon and related ions
Compounds	CF CO CO₂ CO₃ CO₄ CO₅ CO₆ COS CS C₂S₂ CS₂ CSe₂ C₃O₂ C₃S₂ SiC
Carbon ions	Carbides [:C≡C:]²⁻, [::C::]⁴⁻, [:C=C=C:]⁴⁻ Cyanide [:C≡N:]⁻ Cyanate [:O−C≡N:]⁻ Thiocyanate [:S−C≡N:]⁻ Fulminate [:C≡N−O:]⁻ Thiofulminate [:C≡N−S:]⁻
Nanostructures	Graphite intercalation compounds Fullerides
Oxides and related	Oxides Nitrides Metal carbonyls Carbonic acid Bicarbonates Carbonates