Hydrochloric Acid → 4'-Pentyloxybiphenyl-4-boronic Acid

HRID 264597

Reaction equation

[CH2:1]([O:6][C:7]1[CH:12]=[CH:11][C:10]([C:13]2[CH:18]=[CH:17][C:16](Br)=[CH:15][CH:14]=2)=[CH:9][CH:8]=1)[CH2:2][CH2:3][CH2:4][CH3:5].C([Li])CCC.C([O:28][B:29](OC(C)C)[O:30]C(C)C)(C)C.Cl>O1CCCC1>[CH2:1]([O:6][C:7]1[CH:12]=[CH:11][C:10]([C:13]2[CH:18]=[CH:17][C:16]([B:29]([OH:30])[OH:28])=[CH:15][CH:14]=2)=[CH:9][CH:8]=1)[CH2:2][CH2:3][CH2:4][CH3:5]

Participants

Conditions

Temperature: -78 °C

Procedure

To a stirred suspension of 4-(4-n-pentoxyphenyl)bromobenzene (1.0 g, 3.13 mmol) in anhydrous tetrahydrofuran (20 ml) at -78° C. under a nitrogen atmosphere was added n-butyllithium in hexanes (2.5M, 1.32 ml, 3.30 mmol). After a period of 15 rain, triisopropylborate (760 μl, 3.30 mmol) was added. Stirring at -78° C. was continued for 15 min and then at 25° C. for 40 min. The mixture was acidified with 0.5N HCl (20 mL) and then partitioned between ether (50 ml) and water (40 ml). The organic phase was washed with water (3×) and brine and dried with magnesium sulfate. The solvent was removed in vacuo to give 4-(4-n-pentoxyphenyl)phenylboronic acid (750 mg) as a solid: 1H NMR (400 MHz, DMSO-d6) δ0.89 (t, 3H, J=7.2 Hz), 1.38 (m, 4H), 1.72 (m, 2H), 3.99 (t, 2H, 1-6.5Hz), 6.99 (d, 2H, J=8.8 Hz), 7.57 (d, 2H, J=8.2 Hz), 7.60 (d, 2H, J=8.8 Hz), 7.83 (d, 2H, J=8.2 Hz).

Workup

waitat 25° C. for 40 min
custompartitioned between ether (50 ml) and water (40 ml)
washThe organic phase was washed with water (3×) and brine
dry with materialdried with magnesium sulfate
customThe solvent was removed in vacuo

Sources & evidence

ORD record: ord-795bc943dcb3460594dfe3d775cf1ec5
Source dataset: uspto-grants-1997_07
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05646245

Linked notes

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