Tetrachlorocyclopropene

Tetrachlorocyclopropene
Identifiers
CAS Number	6262-42-6 ;
3D model (JSmol)	Interactive image;
ChemSpider	72642;
ECHA InfoCard	100.025.835
PubChem CID	80428;
UNII	4161QF853X ;
CompTox Dashboard (EPA)	DTXSID6021660 ;
	InChI InChI=1S/C3Cl4/c4-1-2(5)3(1,6)7 Key: BLZOHTXDDOAASQ-UHFFFAOYSA-N;
	SMILES ClC1=C(Cl)C1(Cl)Cl;
Properties
Chemical formula	C3Cl4
Molar mass	177.83 g·mol−1
Appearance	Colorless liquid
Density	1.45 g/mL
Boiling point	125 - 130 C
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Tetrachlorocyclopropene is a chemical compound with the formula C₃Cl₄. A colorless liquid, the compound is a reagent used to prepare acetylene derivatives and in organic synthesis.^[1] It was first reported by Tobey and West.^[2] It is prepared by addition of dichlorocarbene to trichloroethylene and then further treating the resultant pentachlorocyclopropane with base to perform dehydrochlorination.^[3]

The compound is used to prepare arylcyclopropanones by a two-step, one-pot procedure beginning with a Friedel-Crafts-like arylation:^[1]

C₃Cl₄ + ArH → ArC₃Cl₃ + HCl (ArH = arene)

The aryltetrachlorocyclopropenes are then hydrolyzed to give the keto-alcohol:

ArC₃Cl₃ + 2 H₂O → ArC₃O(OH) + 3 HCl

The Friedel-Crafts-like arylation employs a Lewis acid catalyst. Treatment of tetrachlorocyclopropene with aluminium trichloride gives the trichlorocyclopropenium ion, which has been isolated as its tetrachloroaluminate salt. X-ray crystallography confirms the structure, revealing very short C-Cl bonds.^[4]

References

^ ^a ^b Oliver Reiser; Armin de Meijere; Brittany M. Klootwyk; Gregory R. Boyce (2019). "Tetrachlorocyclopropene". EEROS. doi:10.1002/047084289X.rt028. ISBN 978-0-471-93623-7.
^ Tobey, S. W.; West, R. (1963). "Tetrachlorocyclopropene and Hexachlorocyclopropane from Pentachlorocyclopropane". Tetrahedron Letters. 4 (18): 1179–1182. doi:10.1016/S0040-4039(01)90799-3.
^ Tobey, S. W.; West, R. (1966). "Tetrachlorocyclopropene, Tetrabromocyclopropene, and Some Fluorinated Cyclopropenes and Cyclopropanes". Journal of the American Chemical Society. 88 (11): 2481–2488. Bibcode:1966JAChS..88.2481T. doi:10.1021/ja00963a023.
^ Clark, George R.; Taylor, Michael J.; Steele, Derek (1993). "Crystal Structure Determination of C₃Cl₃⁺AlCl₄^- and ab initio Studies of the Structure and Vibrational Spectrum of the Trichlorocyclopropenium Cation". Journal of the Chemical Society, Faraday Transactions. 89 (19): 3597. doi:10.1039/ft9938903597.

[eEROS-1] Oliver Reiser; Armin de Meijere; Brittany M. Klootwyk; Gregory R. Boyce (2019). "Tetrachlorocyclopropene". EEROS. doi:10.1002/047084289X.rt028. ISBN 978-0-471-93623-7.

[2] Tobey, S. W.; West, R. (1963). "Tetrachlorocyclopropene and Hexachlorocyclopropane from Pentachlorocyclopropane". Tetrahedron Letters. 4 (18): 1179–1182. doi:10.1016/S0040-4039(01)90799-3.

[3] Tobey, S. W.; West, R. (1966). "Tetrachlorocyclopropene, Tetrabromocyclopropene, and Some Fluorinated Cyclopropenes and Cyclopropanes". Journal of the American Chemical Society. 88 (11): 2481–2488. Bibcode:1966JAChS..88.2481T. doi:10.1021/ja00963a023.

[4] Clark, George R.; Taylor, Michael J.; Steele, Derek (1993). "Crystal Structure Determination of C₃Cl₃⁺AlCl₄^- and ab initio Studies of the Structure and Vibrational Spectrum of the Trichlorocyclopropenium Cation". Journal of the Chemical Society, Faraday Transactions. 89 (19): 3597. doi:10.1039/ft9938903597.

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