Hydrochloric Acid → 2-Methylpyridine-3-boronic acid

Temperature

-70 °C

To a solution of 3-bromo-2-methylpyridine (4.00 g, 23 mmol), triisopropyl borate (6.40 mL, 28 mmol) in 50 mL of 4/1 toluene/THF (4/1, 50 mL) at −78° C. was added was added butyllithium (17 mL, 28 mmol), dropwise. The mixture was allowed to warm up to 30 min at −70° C. LCMS and then to 20° C. HCl (2M) was added to bring the solution to pH1. Then water (20 mL) was added and the mixture was extracted with toluene. The aqueous layer was neutralized with 1 M NaOH and extracted with dichloromethane. The aqueous layer was concentrated to dryness and the white solid was washed with dichloromethane. The combined organic layers were dried over sodium sulfate, filtered and concentrated to give 2.10 g of 2-methylpyridin-3-ylboronic acid as a yellow oil.

1. customto 20° C
2. extractionthe mixture was extracted with toluene
3. extractionextracted with dichloromethane
4. concentrationThe aqueous layer was concentrated to dryness
5. washthe white solid was washed with dichloromethane
6. dry with materialThe combined organic layers were dried over sodium sulfate
7. filtrationfiltered
8. concentrationconcentrated

ORD record

ord-d76e7edf5289489b9b90003e60aa93ae

Source dataset

uspto-grants-2010_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07759337B2