Acetyl bromide
Acetyl bromide is an acyl bromide compound. As is expected, it may be prepared by reaction between phosphorus tribromide and acetic acid: 3 CH3COOH + PBr3 → 3 CH3COBr + H3PO3 As usual for an acid halide, acetyl bromide hydrolyzes rapidly in water, forming acetic acid and hydrobromic acid.