Triisopropyl borate → 4-tert-Butoxyphenylboronic acid

Participants

Reaction Steps

A solution of tert-butyllithium (1.7 M in pentane, 12 ml, CAUTION-PYROPHORIC) was added dropwise to a stirring solution of 4-bromophenyl tert-butyl ether (2.33 g) in tetrahydrofuran (20 ml) at -70° C. After a further 5 minutes the resulting solution of anion was added dropwise to a solution of triisopropyl borate (6 ml) in tetrahydrofuran (10 ml) at -70 ° C. After the addition was complete the reaction mixture was allowed to warm to room temperature. After 20 minutes a solution of saturated aqueous ammonium chloride (25 ml) and ether (25 ml) was added. The layers were separated and the aqueous phase washed with ether (50 ml). The combined organic extracts were washed with dilute hydrochloric acid (5%, 25 ml) and were then dried over anhydrous magnesium sulfate. The solution was filtered and concentrated under reduced pressure to give a white solid. This was purified by column chromatography over silica eluting with ether then methanol to give the sub-title compound as a white solid (0.69 g).

Provenance & Evidence