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

Temperatur

-78 °C

A solution of n-butyl lithium in hexane (1.58N, 55.6 ml, 88 mmol) was added dropwise to a solution of dimethyl methylphosphonate (10.9 g, 88 mmol) in 100 ml of anhydrous THF with stirring at -78° C. under argon atmosphere. After 30 minutes, a solution of methyl o-chlorobenzoate (6.0 g, 35.2 mmol) in 10 ml of anhydrous THF was added dropwise and the mixture was stirred for 30 minutes. The reaction mixture was allowed to warm to 0° C., diluted with 5.3 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 (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-o-chlorophenyl-2-oxoethylphosphonate (8.2 g, 31.2 mmol, yield 88.7%, b.p. 142°-145° C./0.09 mmHg), which was assigned the structure by the following data:

1. stirringthe mixture was stirred for 30 minutes
2. temperatureto warm to 0° C.
3. concentrationconcentrated
4. addition30 ml of water was added to the residue
5. extractionthe mixture 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-Eintrag

ord-b5aaa2b088d14059a74cae6fd54af445

Quelldatensatz

uspto-grants-1988_10

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US04775692