Tributyl borate → 2-Fluoropyridine-4-boronic acid

HRID 1797061Notes

Reaction equation

C([Li])CCC.[F:6][C:7]1[CH:12]=[C:11](I)[CH:10]=[CH:9][N:8]=1.[B:14](OCCCC)([O:20]CCCC)[O:15]CCCC.[OH-].[Na+]>C(OCC)C.O>[F:6][C:7]1[CH:12]=[C:11]([B:14]([OH:20])[OH:15])[CH:10]=[CH:9][N:8]=1

Participants

Conditions

Temperature: -78 °C

Procedure

To a stirred solution of n-butyl lithium (3.2 mL, 2.5M, 8.0 mmol) in dry diethyl ether (20 mL) at −78° C. was added a solution of 2-fluoro-4-iodopyridine (1.5 g, 6.7 mmol) in dry ether (10 mL) and the reaction mixture was stirred at −78° C. for 10 minutes. Tributyl borate (2.4 mL, 2.01 g, 8.7 mmol) was added and the reaction mixture was allowed to stir to room temperature over 2 hours. Water (5 mL) was added followed by 2N aqueous sodium hydroxide solution (10 mL) to sissolve the solids. The organic phase was separated. The aqueous phase was acidified to pH3 using 6N HCl and the resulting white solid was collected by filtration and dried under vacuum to give the title compound, 0.74 g (78%). 1H NMR (DMSO-d6) δ 8.65 (br s, 2H), 8.21 (d, 1H, J=4.8 Hz), 7.59 (t, 1H, J=4.8 Hz), 7.37 (d, 1H, J=1.8 Hz).

Workup

stirringto stir to room temperature over 2 hours
customThe organic phase was separated
filtrationthe resulting white solid was collected by filtration
customdried under vacuum

Sources & evidence

ORD record: ord-cb4ce0eee5d347c0bcf47bf43affc585
Source dataset: uspto-grants-2006_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07034030B2

Reaction notes

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