Acetone → 2-Bromo-1-thiophen-3-yl-butan-1-one

Participants

Reaction Conditions

Reaction Steps

EtMgBr (6.69 ml, 13 mmol, 2 M in ethyl ether) in benzene (10 ml) was cooled to zero degrees C, and tBuOH (1.28 ml, 13 mmol) was slowly added. The reaction mixture was stirred at zero degrees C for 5 minutes, then acetone (530 ul, 7 mmol) was added, followed by a solution of 2-Bromo-1-thiophen-3-yl-butan-1-one (1.3 g, 6 mmol) in 3 ml benzene via cannula. The reaction mixture was heated to reflux for 1 hour, and acetone (250 ul) was added. The reaction mixture was heated 2 hours more at reflux. The reaction was cooled, quenched with 1 N HCl (10 ml), extracted three times with diethyl ether, washed brine, and dried over magnesium sulfate. The solvent was removed in vacuo and the residue chromatographed (5% ethyl acetate/hexanes) to give 247 mg of 2-Bromo-1-thiophen-3-yl-butan-1-one starting material and 520 mg of 5-Thiophen-3-yl-heptane-2,4-dione, 44% .

Provenance & Evidence