Triisopropyl borate → (6-Methoxypyridin-3-yl)boronic acid

To 5-bromo-2-methoxypyridine (8.25 g, 43.9 mmol) and triisopropylborate (10.3 g, 55.0 mmol) in THF (110 mL) at −80° C. was dropwise added n-BuLi (1.6M in hexanes, 30.1 mL, 48.2 mmol). The reaction mixture was gradually warmed to RT over 1 h and then stirred at RT for 16 h. The reaction mixture was quenched by addition of 1N aqueous HCl solution and stirred for 1 h. The aqueous layer was basified with 6N aqueous NaOH to pH=9, extracted with a mixture of EtOAc and Et2O. The aqueous layer was acidified to pH=7 and extracted with EtOAc. The combined organic layers were dried over Na2SO4, filtered and concentrated in vacuo. This material was used in the next step without further purification.

1. customat −80° C.
2. customThe reaction mixture was quenched by addition of 1N aqueous HCl solution
3. stirringstirred for 1 h
4. extractionextracted with a mixture of EtOAc and Et2O
5. extractionextracted with EtOAc
6. dry with materialThe combined organic layers were dried over Na2SO4
7. filtrationfiltered
8. concentrationconcentrated in vacuo
9. customThis material was used in the next step without further purification

ORD record

ord-e8b878219720432db2585f7692e57f54

Source dataset

uspto-grants-2012_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08178557B2