Sulfuric Acid → (2H-1,3-benzodioxol-5-yl)boronic acid

Butyl lithium (BuLi) (5.6 mL, 1.40 equiv) was added dropwise to a solution of 5-bromobenzo[d][1,3]dioxole (2 g, 9.95 mmol, 1.00 equiv) and triisopropyl borate (1.96 g, 14.00 mmol, 1.40 equiv) in THF (20 mL) at −78° C. in a 100-mL 3-necked round-bottom flask under an inert atmosphere of nitrogen. The mixture was stirred at room temperature for 4 hr, quenched with water (10 mL), and acidified with H2SO4 (4.9 g, 50.00 mmol, 5.00 equiv). The resulting solution was allowed to react, with stirring, overnight while the temperature was maintained at reflux. The solution was extracted with 3×50 mL of ethyl acetate and the organic layers combined, dried over anhydrous sodium sulfate and concentrated under vacuum. The resulting solid material was washed with 3×3 mL of ethyl acetate. This resulted in 0.5 g (30%) of benzo[d][1,3]dioxol-5-ylboronic acid as a white solid.

1. customquenched with water (10 mL)
2. customto react
3. stirringwith stirring, overnight while the temperature
4. temperaturewas maintained
5. temperatureat reflux
6. extractionThe solution was extracted with 3×50 mL of ethyl acetate
7. dry with materialdried over anhydrous sodium sulfate
8. concentrationconcentrated under vacuum
9. washThe resulting solid material was washed with 3×3 mL of ethyl acetate
10. customThis resulted in 0.5 g (30%) of benzo[d][1,3]dioxol-5-ylboronic acid as a white solid

ORD record

ord-74057d5425d44e529aa9939fbdb1be28

Source dataset

uspto-grants-2016_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09370522B2