Dimethyl methylphosphonate → Dimethyl 2-o-methylphenyl-2-oxoethylphosphonate

Participants

Reaction Conditions

Reaction Steps

n-Butyl lithium (1.58N, 52.5 ml, 83 mmol) was added dropwise to a stirred solution of dimethyl methylphosphonate (10.3 g, 83 mmol) in 100 ml of anhydrous THF at -78° C. under argon atmosphere. After 30 minutes, methyl o-methylbenzoate (5.0 g, 33 mmol) in 10 ml of anhydrous THF was added dropwise. After being stirred for 30 minutes, this reaction mixture was allowed to warm to 0° C., diluted with 5 ml of acetic acid and 10 ml of water, and concentrated. 20 ml of water was added and the mixture 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 an oil of dimethyl 2-o-methylphenyl-2-oxoethylphosphonate (68 g, 28.1 mmol, yield 85.1%, b.p. 134°-136° C./0.21 mmHg), which was assigned the structure by the following data:

Provenance & Evidence