Oxalyl chloride
| Names | |
|---|---|
| IUPAC name
Oxalyl dichloride
| |
| Systematic IUPAC name
Ethanedioyl dichloride | |
| Other names
Oxalic acid chloride
Oxalic acid dichloride Oxalic dichloride Oxaloyl chloride | |
| Properties | |
| C2O2Cl2 | |
| Molar mass | 126.93 g/mol |
| Appearance | Colorless liquid |
| Odor | Acrid |
| Density | 1.4785 g/cm3 |
| Melting point | −16 °C (3 °F; 257 K) |
| Boiling point | 63–64 °C (145–147 °F; 336–337 K) |
| Reacts | |
| Solubility | Reacts with alcohols, amines, carboxylic acids |
| Hazards | |
| Safety data sheet | Sigma-Aldrich |
| Flash point | Non-flammable |
| Related compounds | |
| Related compounds
|
Oxalic acid Thionyl chloride |
| Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
| Infobox references | |
Oxalyl chloride is the acyl chloride of oxalic acid. It is used as a chlorinating agent, similar to thionyl chloride. Like other acyl chlorides, it is also used for producing derivatives of the parent acid such as esters. Aromatic esters of oxalic acid are used in glowsticks.
Contents
Properties
Chemical
Oxalyl chloride behaves similarly to other acyl chlorides in that reacting with alcohols produces the corresponding ester. Unusually, however, reaction with water does not yield the parent acid, but instead results in decomposition to carbon dioxide, carbon monoxide, and hydrogen chloride.
- C2O2Cl2 + H2O → 2 HCl + CO2 + CO
Other carboxylic acids can be converted to the corresponding acyl chloride by treatment with oxalyl chloride in the presence of a catalytic amount of a nitrogen base such as dimethylformamide, triethylamine, or pyridine. The byproducts produced by this reaction are carbon dioxide and carbon monoxide.
Oxalyl chloride can also be used to formylate arenes by Friedel-Crafts acylation.
Physical
Availability
Oxalyl chloride is available from chemical suppliers but due to its hazards it is often hard to get for amateurs.
Preparation
Oxalyl chloride is usually prepared by reacting anhydrous oxalic acid with phosphorus pentachloride. Unusually, thionyl chloride cannot be used to chlorinate oxalic acid.
Projects
- Make Bis(2,4,6-trichlorophenyl)oxalate for glowsticks
Handling
Safety
Oxalyl chloride is very toxic and presents a severe inhalational hazard. It should only be used with very good ventilation.
Contact with water produces highly toxic carbon monoxide gas, along with corrosive hydrogen chloride.
Storage
In airtight bottles.
Disposal
Should be dissolved in an excess calcium hydroxide solution, which will cause calcium oxalate to precipitate.
