Toluene → (2-Fluoro-4-methylphenyl)boronic acid

Temperature

-40 °C

To a mixture of toluene (160 ml) and THF (40 ml) are added triisopropyl borate (13.56 ml, 58.42 mmole) and 3-fluoro-4-bromotoluene (10.0 g, 48.69 mmole). The mixture is cooled down to −40° C. and n-Butylithium (2.5M in hexane) (23.4 ml, 58.42 mmole) is added slowly over 1 h and the mixture is stirred for an additional hour while the temperature is held at −40° C. The acetone/dry ice bath is removed and the reaction mixture is allowed to warm to −20° C. before a 2.5M HCl solution (20 ml) is added. When the mixture reached rt, the aqueous layer is extracted with EtOAc (3×50 ml), organic extracts are combined, dried over MgSO4 (anhydrous) and evaporated under reduced pressure to give a yellow solid, which is recrystallised from acetonitrile, affording the title product.

1. customis held at −40° C
2. customThe acetone/dry ice bath is removed
3. temperatureto warm to −20° C. before a 2.5M HCl solution (20 ml)
4. additionis added
5. customreached rt
6. extractionthe aqueous layer is extracted with EtOAc (3×50 ml), organic extracts
7. dry with materialdried over MgSO4 (anhydrous)
8. customevaporated under reduced pressure
9. customto give a yellow solid, which
10. customis recrystallised from acetonitrile

ORD record

ord-765903434f2e4a7faa122fa4f28d224c

Source dataset

uspto-grants-2012_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08236803B2