Ethyl formate → Diethyl [difluoro(4-formylphenyl)methyl]phosphonate

Participants

Reaction Conditions

Reaction Steps

To a solution of [Difluoro-(4-iodo-phenyl)-methyl]-phosphonic acid diethyl ester (1.6 g, 4.1 mmol) in anhydrous ether (40 mL) at -78° C. was added dropwise n-butyl lithium (2.5 M in hexanes, 2.5 mL, 6.1 mmol). The brown solution was stirred at -78° C. for 2 minutes. Ethyl formate (0.66 mL, 8.2 mmol) was then added, and the reaction was stirred for 10 minutes at -78° C. The mixture was then quenched with saturated ammonium chloride (10 mL) and warmed to room temperature. The reaction was then diluted with ether. The organic layers were washed with saturated sodium chloride (20 mL), dried over magnesium sulfate, filtered, and concentrated under reduced pressure to yield a yellow oil. Chromatography of the residue [3:7, ethyl acetate:hexanes] gradient to (1:1)] afforded the aldehyde (268 mg, 22%) as a clear oil. 1H NMR (400 MHz, DMSO): δ 10.28 (s, 1H), 8.25 (d, 2H), 7.97 (d, 2H), 4.42 (m, 4H), 1.40 (t, 6H).

Provenance & Evidence