Triisopropyl borate → 4-(2-Fluorophenoxy)phenylboronic acid

Temperature

-78 °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-(2-fluorophenoxy)-4-iodobenzene (3.3 g, 10.51 mmol, 1.00 equiv) in tetrahydrofuran (50 mL). n-BuLi (4.4 mL) was added dropwise with stirring at −78° C. The resulting solution was stirred for 10 mins at −78° C. and then tris(propan-2-yl)borate (2.1 g, 11.17 mmol, 1.06 equiv) was added dropwise with stirring at −78° C. over 10 min. The resulting solution was stirred while the temperature warmed from −78° C. to room temperature. The reaction was then quenched by the addition of saturated aqueous NH4Cl and concentrated under vacuum. The resulting solution was diluted with 10% aquious potassium hydroxide and then washed with ether. The pH of the aqueous was adjusted to 2-4 with hydrogen chloride (37%). The resulting solution was extracted with ethyl acetate and the organic layers combined and dried over anhydrous sodium sulfate and concentrated under vacuum to give 2.2 g (90%) of [4-(2-fluorophenoxy)phenyl]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 10 mins at −78° C.
4. stirringwith stirring at −78° C. over 10 min
5. stirringThe resulting solution was stirred while the temperature
6. temperaturewarmed from −78° C. to room temperature
7. customThe reaction was then quenched by the addition of saturated aqueous NH4Cl
8. concentrationconcentrated under vacuum
9. additionThe resulting solution was diluted with 10% aquious potassium hydroxide
10. washwashed with ether
11. extractionThe resulting solution was extracted with ethyl acetate
12. dry with materialdried over anhydrous sodium sulfate
13. concentrationconcentrated under vacuum

ORD record

ord-a914844365144b98a3869f4af7ea90b7

Source dataset

uspto-grants-2015_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08962635B2