To a solution of Ethyl acetoacetate (10.0 g, 76.9 mmol, 1 .0 eq) in acetic acid (30 mL) was added bromine (12.3 g, 76.9 mmol, 1 .0 eq) at 0 °C over 10 min. The mixture was stirred at 0 °C for 1 h, the solvent was removed under reduced pressure, and the residue was diluted with water (50 mL). The aqueous mixture was extracted with CH2CI2 (50 mL x 3). The combined organic layers were washed with brine (60 mL x 2), dried over MgS04 and concentrated under reduced pressure to give ethyl 4-bromo-3-oxobutanoate (14.3 g, 85 per cent) as a yellow oil.
