Cesium carbonate → Benzoic acid, 2-bromo-4-ethenyl-, ethyl ester

To a stirred solution of ethyl 2-bromo-4-iodobenzoate (5 g, 14.3 mmol) in THF/water (100 mL, 9:1) was added potassium vinyltrifluoroborate (1.89 g, 14.3 mmol), Cs2CO3 (18.27 g, 56.07 mmol) and triphenylphosphine (0.22 g, 0.85 mmol) and the reaction mixture was degassed with argon for 20 min, then charged with PdCl2 (0.05 g, 0.28 mmol). The reaction mixture was heated to reflux for 16 h. The reaction mixture was cooled to ambient temperature and filtered through a Celite® bed and washed with EtOAc. The filtrate was again extracted with EtOAc and the combined organic layers washed with water and brine, dried over Na2SO4 and concentrated under reduced pressure to afford crude compound. The crude compound was purified by column chromatography (SiO2, 100-200 mesh; eluting with 2% EtOAc/petroleum ether) to afford the title compound as a light brown gummy material (2 g, 56%): 1H NMR (400 MHz, CDCl3) δ 7.78 (d, J=8.4 Hz, 1H), 7.71 (d, J=1.2 Hz, 1H), 7.51 (d, J=8.4 Hz, 1H), 6.69 (dd, J=17.6, 10.8 Hz, 1H), 5.86 (d, J=17.6 Hz, 1H), 5.42 (d, J=11.2 Hz, 1H), 4.42 (q, J=7.2 Hz, 2H), 1.43 (t, J=3.6 Hz, 3H); ESIMS m/z 255.18 ([M+H]+); IR (thin film) 1729 cm−1.

1. customthe reaction mixture was degassed with argon for 20 min
2. temperatureThe reaction mixture was heated
3. temperatureto reflux for 16 h
4. filtrationfiltered through a Celite® bed
5. washwashed with EtOAc
6. extractionThe filtrate was again extracted with EtOAc
7. washthe combined organic layers washed with water and brine
8. dry with materialdried over Na2SO4
9. concentrationconcentrated under reduced pressure
10. customto afford crude compound
11. customThe crude compound was purified by column chromatography (SiO2, 100-200 mesh; eluting with 2% EtOAc/petroleum ether)

ORD record

ord-e0a0e69c4bbe4538be11b9e59fe557ff

Source dataset

uspto-grants-2016_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09226500B2