Triethyl phosphonoacetate → Ethyl 5,5,5-trifluoropent-2-enoate

Temperature

0 °C

To a stirred suspension of NaH (60% in oil, 2.15 g, 53.5 mmol) in dry THF (50 mL) was added dropwise ethyl(diethoxyphosphoryl)acetate (11 g, 49 mmol) at 0° C. under N2 atmosphere. The resulting mixture was stirred at 0° C. for 10 min and then cooled to −70° C. A solution of 3,3,3-trifluoropropanal (5.0 g, 44.5 mmol) in dry THF (50 mL) was added to the mixture at −70° C. After the addition, the stirred mixture was allowed to warm to −20° C. over 2 hrs. The reaction mixture was quenched by addition of 5% aqueous NH4Cl (100 mL) at 0° C. and extracted with EtOAc (100 mL). The organic layer was washed with brine (300 mL), dried over Na2SO4 and concentrated in vacuo. The residue was purified by column chromatography (silica gel, petroleum ether: EtOAc=100:1) to give the title compound (3.0 g, 37%) as a colorless oil.

1. temperaturecooled to −70° C
2. additionAfter the addition
3. temperatureto warm to −20° C. over 2 hrs
4. customThe reaction mixture was quenched by addition of 5% aqueous NH4Cl (100 mL) at 0° C.
5. extractionextracted with EtOAc (100 mL)
6. washThe organic layer was washed with brine (300 mL)
7. dry with materialdried over Na2SO4
8. concentrationconcentrated in vacuo
9. customThe residue was purified by column chromatography (silica gel, petroleum ether: EtOAc=100:1)

ORD record

ord-ca2fe85188ee4e2c85b6a1352d295c0f

Source dataset

uspto-grants-2015_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09040547B2