Triethyl borate → (3-Fluoroisoquinolin-6-yl)boronic acid

Temperature

-78 °C

A solution of 6-bromo-3-fluoroisoquinoline (9.10 g, 40.3 mmol) and triethylborate (11.8 g, 80.5 mmol) in THF (100 mL) was cooled to −78° C. Butyllithium (1.6 M in hexanes 50.3 mL, 80.5 mmol) was added dropwise over 45 minutes. Over the course of the addition, the solution changed color from colorless to a light tan. The solution was stirred at −78° C. for 3 hours. The mixture was quenched with HCl (5 N, 120 mL) while in the cold bath at −78° C., diluted with water (100 mL), and then extracted with EtOAc (3×200 mL). The combined organic layers were dried over Na2SO4, filtered and evaporated. The solid residue was triturated with DCM (200 mL), and the solid was recovered by filtration to provide the title compound (6.0 g, 78%). LCMS (API-ES) m/z: 192 (M+H+).

1. additionOver the course of the addition
2. customThe mixture was quenched with HCl (5 N, 120 mL) while in the cold bath at −78° C.
3. additiondiluted with water (100 mL)
4. extractionextracted with EtOAc (3×200 mL)
5. dry with materialThe combined organic layers were dried over Na2SO4
6. filtrationfiltered
7. customevaporated
8. customThe solid residue was triturated with DCM (200 mL)
9. filtrationthe solid was recovered by filtration

ORD record

ord-2067bace97a6460ea0029fa08ba0c9b6

Source dataset

uspto-grants-2011_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07897619B2