N-bromobutanimide → Ethyl 3-cyclopropyl-2-oxopropanoate

Participants

Reaction Steps

To a 0° C. suspension of NBS (439 mmol, 79 g) in a mixture of acetonitrile (400 mL) and water (100 mL) is added a solution of 2-cyclopropylmethyl-[1,3]dithiane-2-carboxylic acid ethyl ester (73.2 mmol, 18.05 g) in acetonitrile (50 mL) over 15 minutes. The reaction is warmed and stirred at room temperature. After 45 minutes, 500 mL of 1:1 hexane/DCM is added. The layers are separated. The organic layer is washed with saturated Na2SO3 (2×225 mL) and brine (2×225 mL), dried with Na2SO4, filtered, and concentrated under reduced pressure to a residue. The residue is diluted in CCl4 and filtered. The filtrate is concentrated to give the title compound (7 g, 61%). LC-ES/MS: 157.0 (M+1).

Provenance & Evidence