Sodium borohydride → (4-Fluoro-2-vinylphenyl)methanol

To a mixture of 1-bromo-4-fluoro-2-vinylbenzene (0.32 g, 1.592 mmol) in tetrahydrofuran (5 mL) at −78° C. was added BuLi (0.764 mL, 1.910 mmol) dropwise. It was then stirred at this temperature for 1 h, then N,N-dimethylformamide (0.185 mL, 2.388 mmol) was added. The reaction mixture was stirred at −78° C. for 30 min, then warmed to rt and stirred at rt for 3 h. It was then quenched with NH4Cl, extracted with ether. The organic layer was dried over MgSO4, filtered and concentrated to obtain 4-fluoro-2-vinylbenzaldehyde (0.2 g) as an oil, which was used in the next step without purification. A mixture of 4-fluoro-2-vinylbenzaldehyde (200 mg, 1.332 mmol) and NaBH4 (50.4 mg, 1.332 mmol) in MeOH (2 mL) was stirred at rt for 1 h. It was then diluted with water, extracted with EtOAc. The organic layer was dried over MgSO4, filtered and concentrated. The residue was purified by biotage, eluting with 20% EtOac/hexane to obtain (4-fluoro-2-vinylphenyl)methanol (150 mg, 0.986 mmol, 74.0% yield) as an oil. 1H NMR (400 MHz, CDCl3) δ 7.35 (dd, J=8.3, 5.9 Hz, 1H), 7.25 (dd, J=10.0, 2.7 Hz, 1H), 7.09-7.02 (m, 1H), 7.02-6.95 (m, 1H), 5.73 (d, J=17.4 Hz, 1H), 5.44 (d, J=11.0 Hz, 1H), 4.75 (d, J=4.9 Hz, 2H).

1. customwas used in the next step without purification
2. extractionextracted with EtOAc
3. dry with materialThe organic layer was dried over MgSO4
4. filtrationfiltered
5. concentrationconcentrated
6. customThe residue was purified by biotage
7. washeluting with 20% EtOac/hexane

ORD record

ord-2177a162338d496bbed9ac76b06e4312

Source dataset

uspto-grants-2016_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09273067B2