Triisopropyl borate → (4-Methoxypyrimidin-5-yl)boronic acid

Temperature

-70 °C

To a solution of 5-bromo-4-methoxypyrimidine (0.460 g, 2.43 mmol) and triisopropyl borate (0.671 mL, 2.92 mmol) in 12 mL of THF at −70° C. was added butyllithium (1.6 m in hexanes, 1.83 mL, 2.92 mmol) dropwise. The addition took 15 minutes and the reaction turned light yellow. The reaction stirred for 30 minutes at −70° C. and was then allowed to warm up to −20° C. The reaction was quenched with ammonium chloride (sat.) and extracted with ethyl acetate. The aqueous layer was concentrated and NaCl (sat.) was added. The aqueous layer was extracted with 3/2 chloroform/iPrOH (3×). The combined organic layers were dried over anhydrous sodium sulfate, filtered and concentrated to give 166 mg of 4-methoxypyrimidin-5-ylboronic acid as a light yellow solid. ES+=155.2 (M+H)

1. additionThe addition
2. temperatureto warm up to −20° C
3. customThe reaction was quenched with ammonium chloride (sat.)
4. extractionextracted with ethyl acetate
5. concentrationThe aqueous layer was concentrated
6. additionNaCl (sat.) was added
7. extractionThe aqueous layer was extracted with 3/2 chloroform/iPrOH (3×)
8. dry with materialThe combined organic layers were dried over anhydrous sodium sulfate
9. filtrationfiltered
10. concentrationconcentrated

ORD record

ord-5abd5172a1b14efaa0ba5ce17195737d

Source dataset

uspto-grants-2010_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07759337B2