Hydrochloric Acid → (2-Acetylfuran-3-yl)boronic acid

Temperature

-70 °C

2,3-Dibromofuran (5.00 g) was dissolved in anhydrous diethyl ether (200 mL) and cooled to −70° C., under an atmosphere of nitrogen. n-Butyllithium (2.5M solution in hexanes, 10.2 mL) was added and the resultant mixture was stirred at −70° C. for 50 minutes. A solution of anhydrous N,N-dimethylacetamide (2.3 mL) in diethyl ether (20 mL) was added and the mixture was warmed to −10° C. The solution was re-cooled to −70° C. and n-butyllithium (2.5M solution in hexanes, 11 mL) was added and the resultant mixture stirred at −70° C. for 1 hour. Tri-isopropyl borate (6.2 mL) was added and the reaction mixture was stirred while the temperature rose from −70° C. to 0° C. The mixture was acidified with 4M hydrochloric acid, extracted into ether, dried (MgSO4) and filtered. The filtrate was concentrated to give an oil which was triturated with tert-butyl methyl ether and the solid obtained was collected by filtration and dried under vacuum to give 2-acetyl-furan-3-boronic acid (0.760 g) as a brown solid.

1. temperaturethe mixture was warmed to −10° C
2. temperatureThe solution was re-cooled to −70° C.
3. customrose from −70° C. to 0° C
4. extractionextracted into ether
5. dry with materialdried (MgSO4)
6. filtrationfiltered
7. concentrationThe filtrate was concentrated
8. customto give an oil which
9. customwas triturated with tert-butyl methyl ether
10. customthe solid obtained
11. filtrationwas collected by filtration
12. customdried under vacuum

ORD record

ord-e195d56f4647469b8dbc287822c61902

Source dataset

uspto-grants-2016_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09266896B2