Bromoacetone

Bromoacetone is a chemical compound with the formula 3CCH2. This colorless liquid is a lachrymatory agent. It is a precursor to other organic compounds.

Bromoacetone was first prepared in the 19th century. It was used in World War I as a chemical weapon, called BA by British and B-stoff (white cross) by Germans. Due to its toxicity, it is obsolete as a riot control agent and is not used anymore.

It is prepared by mixing bromine and acetone.
 * CH3C(O)CH3 +  Br2  →  CH3C(O)CH2Br  +  HBr

The main difficulty with this method is "over-bromination," resulting in di- and tribrominated products. Because of the simplicity of the reaction, it is commonly used for pranks by chemistry students.

It is a versatile reagent in organic synthesis. It is, for example, the precursor to hydroxyacetone (b.p. 35–47°/12 mm, CAS #116-09-6).

Bromoacetone is naturally present (less than 1%) in the essential oil of a seaweed from the vicinity of the Hawaiian Islands. In atmosphere it is degraded by the photochemically produced hydroxyl radicals. When delivered commercially, it may be stabilized with magnesium oxide.