Triisopropyl borate → B-(2-Fluoro-4-phenoxyphenyl)boronic acid

Temperature

-75 °C

Into a 100 mL 3-necked round-bottom flask purged and maintained under an inert atmosphere of nitrogen, was placed a solution of 1-bromo-2-fluoro-4-phenoxybenzene (2 g, 7.49 mmol, 1.00 equiv) in tetrahydrofuran (20 mL). BuLi (1M) (8 mL) was added dropwise with stirring at −70 to −80° C. The resulting solution was stirred for 30 min at −70-80° C. in a liquid nitrogen bath. Tris(propan-2-yl)borate (1.7 g, 9.04 mmol, 1.21 equiv) was added dropwise with stirring at −70 to −80° C. The resulting solution was allowed to react, with stirring, for an additional 2 h while the temperature was maintained at −70 to −80° C. The reaction was then quenched by the addition of 100 mL of water, extracted with ethyl acetate and the organic layers were combined and dried over anhydrous sodium sulfate and concentrated under vacuum. The residue was loaded onto a silica gel column and eluted with ethyl acetate/petroleum ether (1:20) to give 1.6 g (92%) of (2-fluoro-4-phenoxyphenyl)-boronic acid as a white solid.

1. customInto a 100 mL 3-necked round-bottom flask purged
2. temperaturemaintained under an inert atmosphere of nitrogen
3. stirringThe resulting solution was stirred for 30 min at −70-80° C. in a liquid nitrogen bath
4. stirringwith stirring at −70 to −80° C
5. customto react
6. stirringwith stirring, for an additional 2 h while the temperature
7. temperaturewas maintained at −70 to −80° C
8. customThe reaction was then quenched by the addition of 100 mL of water
9. extractionextracted with ethyl acetate
10. dry with materialdried over anhydrous sodium sulfate
11. concentrationconcentrated under vacuum
12. washeluted with ethyl acetate/petroleum ether (1:20)

ORD record

ord-a48a60e3389446b9b198f265910d40d9

Source dataset

uspto-grants-2015_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08962831B2