Hydrochloric Acid → 3-Cyanophenylboronic acid

Participants

Reaction Conditions

Reaction Steps

3-Bromobenzonitrile (3.6 g, 20 mmol) in anhydrous THF (100 ml) is treated with triisopropyl borate (13 ml, 56 mmol) followed by 1.6 M butyllithium in hexane (14 ml, 22 mmol) over 15 min. at −78° C. The reaction is stirred at −78° C. for 45 min . then warmed to room temperature over 60 min. The reaction mixture is poured into 40 ml 2 N HCl and the precipitated solid is collected . The filter cake is washed with water (3×) and methylene chloride (3×) to yield 3-cyanophenyl boronic acid (2.3 g, 15.6 mmol). 1H NMR (CDCl3, 300 MHz) δ 8.4 (br, 2H), 8.13 (s, 1H), 8.07 (d, 1H), 7.85 (d, 1H), 7.55 (t, 1H). EI MS M+ 147.

Provenance & Evidence