Oxalyl chloride

Oxalyl chloride

Names
Preferred IUPAC name Oxalyl dichloride
Systematic IUPAC name Ethanedioyl dichloride
Other names Oxalic acid chloride Oxalic acid dichloride Oxalic dichloride Oxaloyl chloride
Identifiers
CAS Number	79-37-8 Y
3D model (Jmol)	Interactive image
ChemSpider	59021 N
ECHA InfoCard	100.001.092
EC Number	201-200-2
PubChem	65578
RTECS number	KI2950000
InChI InChI=1S/C2Cl2O2/c3-1(5)2(4)6 N Key: CTSLXHKWHWQRSH-UHFFFAOYSA-N N InChI=1/C2Cl2O2/c3-1(5)2(4)6 Key: CTSLXHKWHWQRSH-UHFFFAOYAG
SMILES ClC(=O)C(=O)Cl
Properties
Chemical formula	C2O2Cl2
Molar mass	126.93 g/mol
Appearance	Colorless liquid
Density	1.4785 g/mL
Melting point	−16 °C (3 °F; 257 K)
Boiling point	63 to 64 °C (145 to 147 °F; 336 to 337 K) at 1.017 bar
Solubility in water	Reacts
Refractive index (nD)	1.429
Hazards
Main hazards	Toxic, corrosive, lachrymator
Safety data sheet	External MSDS
GHS pictograms
GHS signal word	Danger
GHS hazard statements	H314, H331
GHS precautionary statements	P261, P280, P305+351+338, P310
EU classification (DSD)	T
R-phrases	R14 R23 R29 R34
S-phrases	(S1/2) S26 S30 S36/37/39 S38 S45 S61
NFPA 704	3 1
Related compounds
Related acyl chlorides	Malonyl chloride Succinyl chloride phosgene
Related compounds	Oxalic acid Diethyl oxalate Oxamide Oxalyl hydrazide Cuprizon 1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

Oxalyl chloride is a chemical compound with the formula (COCl)₂. This colourless, sharp-smelling liquid, the diacid chloride of oxalic acid, is a useful reagent in organic synthesis. It can be prepared by treating oxalic acid with phosphorus pentachloride.

Oxalyl chloride reacts with water giving off gaseous products only: hydrogen chloride (HCl), carbon dioxide (CO
2), and carbon monoxide (CO).

In this, it is quite different from other acyl chlorides which hydrolyze with formation of hydrogen chloride and the original carboxylic acid.

The solution comprising DMSO and oxalyl chloride, followed by quenching with triethylamine converts alcohols to the corresponding aldehydes and ketones via the process known as the Swern oxidation.

Oxalyl chloride is mainly used together with a N,N-dimethylformamide catalyst in organic synthesis for the preparation of acyl chlorides from the corresponding carboxylic acids. Like thionyl chloride, the reagent degrades in volatile side products in this application, which simplifies workup. One of the minor by-products from this reaction is a potent carcinogen. Relative to thionyl chloride, oxalyl chloride tends to be a milder, more selective reagent. It is also more expensive than thionyl chloride so it tends to be used on a smaller scale.