Acetyl bromide

Acetyl bromide is a chemical compound with the formula CH₃COBr. It is a colorless liquid with a pungent odor, used primarily in organic chemistry as a reagent or in the synthesis of other compounds. Acetyl bromide belongs to the class of acyl halides, specifically a member of the bromides and an acyl bromide.

Properties

Acetyl bromide is characterized by its strong, pungent odor and its colorless appearance. It is highly reactive, especially with water and alcohols, leading to the formation of acetic acid and hydrobromic acid. This reactivity is due to the presence of the acyl halide functional group, which is known for its electrophilic properties.

Synthesis

The synthesis of acetyl bromide typically involves the reaction of acetic acid with phosphorus tribromide (PBr₃) or hydrobromic acid in the presence of a dehydrating agent. The reaction with phosphorus tribromide can be represented as follows:

CH₃COOH + PBr₃ → CH₃COBr + H₃PO₃

Applications

In organic synthesis, acetyl bromide is used as a reagent for the introduction of the acetyl group into other organic compounds. It is particularly useful in the acetylation of alcohols and phenols, where it acts more selectively than other acylating agents such as acetyl chloride. Additionally, it can be used in the preparation of acetate esters and in the synthesis of various pharmaceuticals and fine chemicals.

Safety

Acetyl bromide is a highly reactive and corrosive substance. It poses risks of severe burns upon contact with skin and can cause respiratory issues if inhaled. Proper safety precautions, including the use of personal protective equipment (PPE) such as gloves and goggles, and working in a well-ventilated area or fume hood, are essential when handling this chemical.

See also

• Acyl chloride
• Acetic acid
• Organic synthesis