Acetyl bromide explained

Acetyl bromide is an acyl bromide compound. As is expected, it may be prepared by reaction between phosphorus tribromide and acetic acid:^[1]

3 CH₃COOH + PBr₃ → 3 CH₃COBr + H₃PO₃

As usual for an acid halide, acetyl bromide hydrolyzes rapidly in water, forming acetic acid and hydrobromic acid. It also reacts with alcohols and amines to produce acetate esters and acetamides, respectively.

References

1. 10.1021/ja01858a502 . . The Preparation of Acetyl Bromide . Theodore M. Burton and Ed. F. Degering . 1940 . 62 . 227.