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

Participants

Reaction Conditions

Reaction Steps

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).

Provenance & Evidence