Chloroacetone

Chloroacetone is a liquid, a chemical compound with the formula. Regulated for its potential as a tear gas, it is primarily a chemical intermediate in commerce.

Properties

At STP it is a colorless liquid with a pungent odor. On exposure to light, it turns to a dark yellow-amber color. It was used as a tear gas in World War I.

Synthesis

Chloroacetone may be synthesized from the reaction between chlorine and diketene, or by the chlorination of acetone.

Applications

Chloroacetone is primarily an intermediate in chemical manufacture. In the early 2000s, it was used to make dye couplers for colour film photography. In the pharmaceutical industry, it is a precursor to phenoxyacetone.
It is also used in the Feist-Benary synthesis of furans:

Purification

Chloroacetone purchased from commercial suppliers contains 5% impurities including mesityl oxide, which is not removed by distillation. Mesityl oxide can be oxidized using acidified KMnO₄ to form a diol, which is removed on subsequent distillation.

Transportation regulations

Transportation of unstabilized chloroacetone has been banned in the United States by the US Department of Transportation. Stabilized chloroacetone is in hazard class 6.1. Its UN number is 1695.