Dichloroacetaldehyde

Dichloroacetaldehyde
Names
	IUPAC name 2,2-dichloroethanal
	Other names dichloroethanal
Identifiers
CAS Number	79-02-7 ;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:34214;
ChemSpider	21106511;
ECHA InfoCard	100.001.063
EC Number	201-169-5;
KEGG	C14858;
PubChem CID	6576;
UNII	9GT3DHH725;
UN number	1993
CompTox Dashboard (EPA)	DTXSID3021560 ;
	InChI InChI=1S/C2H2Cl2O/c3-2(4)1-5/h1-2H Key: NWQWQKUXRJYXFH-UHFFFAOYSA-N;
	SMILES C(=O)C(Cl)Cl;
Properties
Chemical formula	C2H2Cl2O
Molar mass	112.94 g·mol−1
Density	1.4 g/mL
Melting point	−50 °C (−58 °F; 223 K)
Boiling point	88 °C (190 °F; 361 K)
Solubility in water	forms hydrate
Hazards
	GHS labelling:[1]
Pictograms
Signal word	Danger
Hazard statements	H301, H310, H314, H330, H335, H351, H400
Precautionary statements	P203, P260, P261, P262, P264, P264+P265, P270, P271, P273, P280, P284, P301+P316, P301+P330+P331, P302+P352, P302+P361+P354, P304+P340, P305+P354+P338, P316, P317, P318, P319, P320, P321, P330, P361+P364, P363, P391, P403+P233, P405, P501
Related compounds
Related compounds	chloroacetaldehyde, trichloroacetaldehyde
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Dichloroacetaldehyde is a chlorinated aldehyde with the chemical formula HCCl₂CHO. Along with monochloroacetaldehyde and trichloroacetaldehyde, it is one of the three possible chlorinated acetaldehydes.

Properties and reactions

Dichloroacetaldehyde is a highly volatile liquid that is easily soluble in water to form Hydrates. A geminal diol, also known as monohydrate, 2,2-dichloro-1,1-ethanediol, is formed in water.^[1]

The compound decomposes when heated. In the presence of Lewis acids such as antimony trichloride, iron(III) chloride, aluminum trichloride, tin(IV) chloride or boron trifluoride, the trimer hexachloroparaldehyde (2,4,6-tris(dichloromethyl)-1,3,5-trioxane) can be obtained.^[1] The trimer forms colourless crystals that melt at 131–132 °C. At the boiling point of 210–220 °C, dichloroacetaldehyde decomposes.^[1]

Reduction with lithium aluminium hydride gives dichloroethanol.^[2]

Uses

Dichloroacetaldehyde is used to produce other chemical compounds such as mitotane.^[3] Condensation with chlorobenzene yields p,p′-dichloro-1,1-diphenyl-2,2-dichloroethane, which was previously used as an insecticide:^[1]

Synthesis

Dichloroacetaldehyde can be obtained by chlorinating acetaldehyde or paraldehyde. Hypochlorination of 1,2-dichloroethylene using chlorine and water produces pure dichloroacetaldehyde.^[1]^[4]

References

^ ^a ^b ^c ^d ^e Jira, R.; Kopp, E.; McKusick, B.C.; Röderer, G.; Bosch, A.; Fleischmann, G.: Chloroacetaldehydes in Ullmann’s Encyclopedia of Industrial Chemistry, 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, doi:10.1002/14356007.a06_527.pub2.
^ Sroog, C. E.; Woodburn, H. M. (1952). "2,2-Dichloroethanol". Organic Syntheses. 32: 46. doi:10.15227/orgsyn.032.0046.
^ Ullmann, Fritz (2000). Ullmann's Encyclopedia of Industrial Chemistry. Vol. 1 (6th ed.). Germany: Wiley. ISBN 9783527306732.
^ NLM Hazardous Substances Data Bank entry for Dichloroacetaldehyde

[Ullmann-1] Jira, R.; Kopp, E.; McKusick, B.C.; Röderer, G.; Bosch, A.; Fleischmann, G.: Chloroacetaldehydes in Ullmann’s Encyclopedia of Industrial Chemistry, 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, doi:10.1002/14356007.a06_527.pub2.

[2] Sroog, C. E.; Woodburn, H. M. (1952). "2,2-Dichloroethanol". Organic Syntheses. 32: 46. doi:10.15227/orgsyn.032.0046.

[3] Ullmann, Fritz (2000). Ullmann's Encyclopedia of Industrial Chemistry. Vol. 1 (6th ed.). Germany: Wiley. ISBN 9783527306732.

[HSDB-4] NLM Hazardous Substances Data Bank entry for Dichloroacetaldehyde

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