Triisopropyl borate → 3-Methyl-2-pyridineboronic acid

Temperature

0 °C

A 100-mL, 3-necked round-bottom flask was charged with 2-bromo-3-methylpyridine (1.00 g, 5.81 mmol) and diethyl ether (30 mL). A solution of isopropylmagnesium chloride (2 M in THF, 8.0 mL, 16.0 mmol) was added dropwise with stirring at 0° C., and the resulting solution stirred for 3 h at 0° C. Triisopropyl borate (2.6 g, 13.8 mmol) was added, and the solution stirred for 1 h at room temperature. The reaction was then quenched by the addition of saturated aqueous ammonium chloride solution (10 mL). The aqueous layer was separated and extracted with ethyl acetate (2×10 mL). The combined organic layers were dried over anhydrous sodium sulfate, filtered, and concentrated under vacuum to afford 3-methylpyridin-2-ylboronic acid (0.730 g, 92%) as light yellow oil. MS (ESI, pos. ion) m/z 138 [M+H]+.

1. stirringthe resulting solution stirred for 3 h at 0° C
2. stirringthe solution stirred for 1 h at room temperature
3. customThe reaction was then quenched by the addition of saturated aqueous ammonium chloride solution (10 mL)
4. customThe aqueous layer was separated
5. extractionextracted with ethyl acetate (2×10 mL)
6. dry with materialThe combined organic layers were dried over anhydrous sodium sulfate
7. filtrationfiltered
8. concentrationconcentrated under vacuum

ORD record

ord-8c35a7a222fb42b0bb0a53dbb62a44e0

Source dataset

uspto-grants-2016_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09388161B2