Hydrochloric Acid → Dibenzo(b,d)furan-2-ylboronic Acid (contains varying amounts of Anhydride)

Temperature

-80 °C

In a 300 mL three-neck flask was put 3.6 g (14 mmol) of 3-bromodibenzofuran. The air in the flask was replaced with nitrogen. To this mixture was added 70 mL of THF, and this solution was cooled to −80° C. Then, 10 mL (16 mmol) of n-butyllithium (a 1.6 mol/L hexane solution) was dripped into this solution with a syringe. After that, this solution was stirred at the same temperature for 2 hours. Then, 3.4 mL (30 mmol) of trimethyl borate was added to this solution, and the mixture was stirred for 4 days while its temperature was returned to room temperature. After that, about 30 mL of diluted hydrochloric acid (1.0 mol/L) was added to this solution, followed by stirring for 1 hour. Then, the aqueous layer of this mixture was extracted with ethyl acetate, and the ethyl acetate solution and the organic layer were combined and washed with saturated brine. The organic layer was dried with magnesium sulfate. Then, this mixture was gravity filtered. The resulting filtrate was concentrated to give a solid. The solid was washed with hexane, whereby 0.70 g of a white powder was obtained in 27% yield, which was the substance to be produced.

1. customIn a 300 mL three-neck flask was put
2. stirringthe mixture was stirred for 4 days while its temperature
3. customwas returned to room temperature
4. stirringby stirring for 1 hour
5. extractionThen, the aqueous layer of this mixture was extracted with ethyl acetate
6. washwashed with saturated brine
7. dry with materialThe organic layer was dried with magnesium sulfate
8. filtrationfiltered
9. concentrationThe resulting filtrate was concentrated
10. customto give a solid
11. washThe solid was washed with hexane

ORD record

ord-9cbad923987948a28a6617b0f9bb3e86

Source dataset

uspto-grants-2014_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08771840B2