Triisopropyl borate → 2-Fluorophenylboronic acid

Temperature

-78 °C

A solution of 50 g (285.6 mmol) of 2-fluorobromobenzene in 400 mL of tetrahydrofuran was cooled to −78° C. and 200 mL (320.0 mmol) of 1.6M n-Butyllithium was added via a cannula. The mixture was stirred at −78° C. for 60 minutes, then 98.9 mL (428.4 mmol) of triisopropyl borate was added via a cannula and stirring was continued for 60 minutes. The cooling bath was removed and the mixture was stirred at ambient temperature for 1.5 hours, then 150 mL of 6N hydrochloric acid was added and stirring was continued for 1.5 hours. To the mixture was added 100 mL of brine, and then the organic layer was separated and the aqueous layer was extracted three times with 30 mL each of ether. The combined organic extracts were dried (MgSO4), filtered and concentrated in vacuo. The residue was recrystallized from water to afford 25.2 g (63%) of the title compound.

1. stirringstirring
2. waitwas continued for 60 minutes
3. customThe cooling bath was removed
4. stirringthe mixture was stirred at ambient temperature for 1.5 hours
5. addition150 mL of 6N hydrochloric acid was added
6. stirringstirring
7. waitwas continued for 1.5 hours
8. additionTo the mixture was added 100 mL of brine
9. customthe organic layer was separated
10. extractionthe aqueous layer was extracted three times with 30 mL each of ether
11. dry with materialThe combined organic extracts were dried (MgSO4)
12. filtrationfiltered
13. concentrationconcentrated in vacuo
14. customThe residue was recrystallized from water

ORD record

ord-4ff4fb95a88d499891cf9a267ac8b82a

Source dataset

uspto-grants-2003_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06617351B1