Hydrochloric Acid → 9-(dibenzo[b,d]thiophen-4-yl)-9H-carbazol-3-ylboronic acid

Participants

Reaction Conditions

Reaction Steps

An excess of 1.6M n-BuLi in hexane (14 mL, 22.3 mmol) was added to a solution of 3-bromo-9-(diberizo[b,d]thiophen-4-yl)-9H-carbazole (8.7 g, 20.3 mmol) in 100 ml dry tetrahydrofuran at −78° C. under N2. The reaction mixture was then maintained at 0° C. for 1 h before cooling to −78° C. Trimethylborate (2.8 g, 26.4 mmol) was added dropwise; the solution was then warmed slowly to room temperature and stirred for 24 h. 2N HCl (50 ml) was added and then the mixture was stirred for a further 1 h. The reaction mixture was extracted with ethyl acetate and water, dried with anhydrous magnesium sulfate, the solvent was evaporated in vacuum, and the residue was crystallized from n-hexane to give the 9-(dibenzo[b,d]thiophen-4-yl)-9H-carbazol-3-ylboronic acid 4.7 g (59%)

Provenance & Evidence