Hexane → Dimethyl 2-m-chlorophenyl-2-oxoethylphosphonate

Temperature

-78 °C

A solution of n-butyl lithium in hexane (1.63N, 45 ml, 73.3 mmol) was added dropwise to a solution of dimethyl methylphosphonate (9.1 g, 73.3 mmol) in 100 ml of anhydrous THF with stirring at -78° C. under argon atmosphere, and the mixture was stirred for 30 minutes. Then, methyl m-chlorobenzoate (5.0 g, 29.3 mmol) in 10 ml of anhydrous THF was further added dropwise and the mixture was stirred for 30 minutes. This reaction mixture was allowed to warm to 0° C., diluted with 4.4 ml of acetic acid and 10 ml of water, and concentrated. 30 ml of water was added to the residue and the mixture was extracted with ethyl acetate (50 ml×2). The combined ethyl acetate layers were washed with water (30 ml×1) and brine (30 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-m-chlorophenyl-2-oxoethylphosphonate (6.5 g, 24.8 mmol, yield 84%, b.p. 144°-146° C./0.06 mmHg), which was assigned the structure by the following data:

1. stirringthe mixture was stirred for 30 minutes
2. stirringthe mixture was stirred for 30 minutes
3. temperatureto warm to 0° C.
4. concentrationconcentrated
5. addition30 ml of water was added to the residue
6. extractionthe mixture was extracted with ethyl acetate (50 ml×2)
7. washThe combined ethyl acetate layers were washed with water (30 ml×1) and brine (30 ml×1)
8. dry with materialdried over anhydrous sodium sulfate
9. concentrationconcentrated
10. distillationThe residue was distilled under reduced pressure

ORD record

ord-759f6c2f77a048ea9a7c870fd62d0f7d

Source dataset

uspto-grants-1988_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04775692