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

Temperature

-78 °C

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:

1. stirringAfter the mixture was stirred for 30 minutes
2. stirringthe mixture was stirred for 30 minutes
3. temperatureto warm to 0° C.
4. concentrationconcentrated
5. extractionThe residue was extracted with ethyl acetate (50 ml×2)
6. washThe combined ethyl acetate layers were washed with water (20 ml×1) and brine (20 ml×1)
7. dry with materialdried over anhydrous sodium sulfate
8. concentrationconcentrated
9. distillationThe residue was distilled under reduced pressure

ORD record

ord-68b032d5ba5a4a4cbec4c1c14c19dc25

Source dataset

uspto-grants-1988_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04775692