3-(Trifluoromethyl)phenol → 3-(3-Trifluoromethyl-phenoxy)-but-2-enoic acid ethyl ester

Temperature

130 °C

A mixture of 3-trifluoromethyl-phenol (1.09 mL, 8.96 mmol) and ethyl-2-butynoate (2.0 g, 17.83 mmol) in tetrahydrofuran (14 mL) was treated with 1,8-diazabicyclo[5.4.0]undec-7-ene (1.4 mL, 9.37 mmol). The reaction was then heated at 130° C. for 2 h. At this time, the reaction was concentrated in vacuo. The residue dissolved in dichloromethane (100 mL) and was washed with a 2N aqueous hydrochloric acid solution (1×100 mL), a 1N aqueous sodium hydroxide solution (1×100 mL) and a saturated aqueous sodium chloride solution (1×100 mL). The organics were then dried over magnesium sulfate, filtered, rinsed with dichloromethane and concentrated in vacuo. Purification by Analogix flash chromatography (40 g, 1-10% ethyl acetate/hexanes) afforded 3-(3-trifluoromethyl-phenoxy)-but-2-enoic acid ethyl ester (1.31 g, 53%) as a clear, colorless oil: HR-ES-MS m/z calculated for C13H13O3F3 [M+H]+ 275.0890, observed 275.0889; 1H NMR (400 MHz, DMSO-d6) δ ppm 1.13 (t, J=7.1 Hz, 3H), 2.45 (s, 3H), 4.01 (q, J=7.1 Hz, 2H), 4.68 (s, 1H), 7.49 (d, J=7.9 Hz, 1H), 7.57 (br. s., 1H), 7.66-7.75 (m, 2H).

1. concentrationAt this time, the reaction was concentrated in vacuo
2. dissolutionThe residue dissolved in dichloromethane (100 mL)
3. washwas washed with a 2N aqueous hydrochloric acid solution (1×100 mL)
4. dry with materialThe organics were then dried over magnesium sulfate
5. filtrationfiltered
6. washrinsed with dichloromethane
7. concentrationconcentrated in vacuo
8. customPurification by Analogix flash chromatography (40 g, 1-10% ethyl acetate/hexanes)

ORD record

ord-e96fd3d32374498c9fc3e2b316dbad72

Source dataset

uspto-grants-2010_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07741327B2