Ethyl chloroformate → 4,4,4-Trifluoro-2-(triphenyl-lambda5-phosphanylidene)-butyric acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

To a suspension of (3,3,3-trifluoropropyl)-triphenylphosphonium iodide (105 g, 20.6 mmol) in THF (40 mL) at −78° C. was added slowly a solution of lithium bis(trimethylsilyl)amide (1.0 M in THF, 41.2 mL) through an addition funnel under nitrogen. The resulting mixture was stirred at −78° C. for 15 min followed by dropwise addition of a solution of ethylchloroformate (3.92 mL, 41.2 mmol) in THF (40 mL). The reaction mixture was then allowed to warm up to 25° C. while stirring. The reaction mixture was partitioned between EtOAc (300 mL) and brine (300 mL). The organic layer was dried over Na2SO4 and evaporated in vacuo to afford a crude solid which was purified by flash chromatography (EtOAc:hexanes 1:1) to provide a light tan solid (7.18 g) in 81% yield. Mass Spectrum (+ESI): 431 [M+H]+.

Provenance & Evidence