4-Bromo-2-fluorophenol → 1-(3-Fluoro-4-hydroxyphenyl)propan-1-one

Participants

Reaction Conditions

Reaction Steps

A mixture of 4-bromo-2-fluorophenol (1.0 g, 5.24 mmol) in tetrahydrofuran (15 mL) was chilled to -78° C. and butyllithium (4.6 mL, 11.5 mmol, 2.5 M solution) was added rapidly, dropwise. The reaction was stirred 12 min and N-methyl-N-methoxypropionamide (the compound of Preparation 9 , 0.735 g, 6.28 mmol in 1 mL of tetrahydrofuran with a 1 mL rinse) was added. The reaction was allowed to stir 5 min at -78° C. and then it was warmed to ambient temperature. A few drops of water were added; then the solvent was removed at reduced pressure. The residue was taken up in methylene chloride and washed with aqueous ammonium chloride and brine. The organic layer was dried and concentrated. The residue was flash chromatographed on silica gel (1×2.5 inches packed in hexane) with elution proceeding as follows: 10% ethyl acetate/hexane (250 mL), discarded forerun; 20% ethyl acetate/hexane (250 mL), 0.186 g of a yellow crystalline solid which had NMR identical to that of preparation 7.

Provenance & Evidence