Ethyl [bis(2,2,2-trifluoroethoxy)phosphinyl]acetate

Ethyl [Bis(2,2,2-trifluoroethoxy)phosphinyl]acetate is a reagent used in the preparation of spiroketal EBC-23; an anticancer agent, scytonemin A; a novel calcium antagonist and other useful organic compounds.

To stirred solution of 18-crown-6 (4.40 g, 16.65 mmol), THF (20 mL), and bis (2,2,2-trifluoroethyl) phosphite (1) (0.55 mL, 3.75 mmol), KHMDS (8.0 mL, 4.00 mmol, 0.5 M in toluene) was added via syringe in a dropwise manner at -78 oC. Ethyl chloroacetate (0.35 mL, 3.30 mmol) was added to the flask after 15 min. The reaction flask was allowed to warm to room temperature and stir for 4 hr. After standard workup procedure, the crude product was then purified by flash column chromatography (2:1-1:1 hexanes:EtOAc, Rf = 0.25 in 2:1 hexanes:EtOAc) yielding Ethyl [bis(2,2,2-trifluoroethoxy)phosphinyl]acetate (808 mg, 2.43 mmol, 73.4%) as a yellow syrup.