Water → 3-Pyridinylboronic acid

Temperature

-78 °C

To -78° C. cooled n-BuLi (61 ml; 2.5 M hexane solution) was added 3-bromopyridine (20.0 g), dissolved in Et2O (-78° C.) (100 ml) by cannula during 5 minutes. After 10 minutes, a precooled (-78° C.) solution of trimethyl-borate (17.1 g) in Et2O (80 ml) was added. The reaction mixture was stirred at -78° C. for 1 hour, warmed to room temperature during 1 hour, and stirred at room temperature for 1/2 hour. To the reaction mixture was added 20 ml water and stirring continued. The resulting solid percipitate was collected and the supernatent concentrated to a residue. To the residue was added ethyl alcohol (100 ml) and acetic acid (8 ml) followed by heating at reflux for 35 minutes, cooling to room temperature and concentrating to dryness to give a pale yellow foamy material. The crude product was used directly in the next step.

1. temperaturewarmed to room temperature during 1 hour
2. stirringstirred at room temperature for 1/2 hour
3. stirringstirring
4. customThe resulting solid percipitate was collected
5. concentrationthe supernatent concentrated to a residue
6. additionTo the residue was added ethyl alcohol (100 ml) and acetic acid (8 ml)
7. temperatureby heating
8. temperatureat reflux for 35 minutes
9. temperaturecooling to room temperature
10. concentrationconcentrating to dryness
11. customto give a pale yellow foamy material

ORD record

ord-b81f97d120584db7aba32278dc1d085a

Source dataset

uspto-grants-1999_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05908840