Trimethyl borate → 4-(Cyclopropylmethoxy)phenylboronic acid

Participants

Reaction Conditions

Reaction Steps

Butyl lithium (2.5 M in hexane, 14.4 mL, 36 mmol) was added dropwise (5 min) to a cooled (−78° C.) and stirred solution of 4-(cyclopropylmethoxy)iodobenzene 1 (9.00 g, 32.8 mmol) in tetrahydrofuran (100 mL). After 20 min, trimethyl borate (11.3 mL, 10.4 g, 100 mmol) was added dropwise (10 mL). The reaction was stirred for an additional 20 min, and was then allowed to warm to rt. The reaction was quenched with 1 M hydrochloric acid (300 mL) and stirring was continued for 30 min. The product was extracted with diethyl ether (4×100 mL) and then the combined organic extracts were dried over anhydrous magnesium sulfate and concentrated in vacuo. The residue was dissolved in toluene and then concentrated. This operation was repeated (5×) until the distillate was colorless and left 5.67 g (90%) of crude product. This material was used without purification or analysis.

Provenance & Evidence