Acetic Acid → Dimethyl 2-oxo-4-methyloctylphosphonate

Temperature

-70 °C

Under an atmosphere of nitrogen, 375 ml of a 1.33 M solution of n-butyllithium in n-hexane were added dropwise to a solution of 61.9 g of dimethyl methylphosphonate in 587 ml of tetrahydrofuran at -70° C. After stirring the mixture for one hour at -70° C., a solution of 40 g of sec-butyl 3-methylheptanoate (prepared as described in Reference Example 1) in 70 ml of tetrahydrofuran was added dropwise at -70° C., and the mixture was stirred at the same temperature for 4 hours and then stirred overnight at room temperature. The reaction mixture was then acidified with acetic acid and filtered to remove the precipitated solid, and the filtrate was concentrated under reduced pressure. The residue was diluted with ethyl acetate, washed with water and a saturated aqueous solution of sodium chloride, dried over magnesium sulphate and concentrated under reduced pressure. The residue was purified by distillation under reduced pressure to give 42 g of the title compound having the following physical characteristics:

1. stirringthe mixture was stirred at the same temperature for 4 hours
2. stirringstirred overnight at room temperature
3. filtrationfiltered
4. customto remove the precipitated solid
5. concentrationthe filtrate was concentrated under reduced pressure
6. additionThe residue was diluted with ethyl acetate
7. washwashed with water
8. dry with materiala saturated aqueous solution of sodium chloride, dried over magnesium sulphate
9. concentrationconcentrated under reduced pressure
10. distillationThe residue was purified by distillation under reduced pressure

ORD record

ord-a7b691bee5f24488998202b3d4e00e59

Source dataset

uspto-grants-1981_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04294849