Hexane → Dimethyl [2-(4-chlorophenyl)-2-oxoethyl]phosphonate

Participants

Reaction Conditions

Reaction Steps

A solution of n-butyl lithium in hexane (1.63N, 43 ml, 70 mmol) was added dropwise to a solution of dimethyl methylphosphonate (8.68 g, 70 mmol) in 100 ml of anhydrous THF with stirring at -78° C. under argon atmosphere. After the mixture was stirred for 30 minutes, a solution of methyl p-chlorobenzoate (4.8 g, 28 mmol) in 10 ml of anhydrous THF was added dropwise and the mixture was stirred for 30 minutes. This reaction mixture was allowed to warm to 0° C., diluted with 4.2 ml of acetic acid and 10 ml of water, and concentrated. The residue was extracted with ethyl acetate (50 ml×2). The combined ethyl acetate layers were washed with water (20 ml×1) and brine (20 ml×1), dried over anhydrous sodium sulfate, and concentrated. The residue was distilled under reduced pressure to give a colorless transparent oil of dimethyl 2-p-chlorophenyl-2-oxoethylphosphonate (5.6 g, 21.3 mmol, yield 76.2%, b.p. 146°-149° C./0.07 mmHg), which was assigned the structure by the following data:

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