反应详情

In a 300 ml three-necked flask, 7.2 g of 4-bromodibenzofuran was dissolved in −78° C. anhydrous tetrahydrofuran (THF) under an argon atmosphere. Then, 20 ml of an n-butyl lithium-n-hexane solution (1.6 M, 1.1 eq) was added and stirred for 1 hour. 4.23 ml (1.3 eq) of trimethoxyborane (B(OMe)3) was added and stirred for 2 hours, and the temperature of the reaction system was increased to room temperature. 200 ml of 1 N hydrochloric acid was added into the reactant and stirred for 3 hours. An organic layer was separated, and solvents were distilled off. In the crude product thus obtained, hexane was added. Precipitated product was filtered to obtain 4.94 g of dibenzofuran-4-boronic acid as a white solid (yield 80%). The product was measured by FAB-MS, and dibenzofuran-4-boronic acid having a molecular weight of 212 was detected.

1. stirringstirred for 2 hours
2. stirringstirred for 3 hours
3. customAn organic layer was separated
4. distillationsolvents were distilled off
5. customIn the crude product thus obtained
6. filtrationPrecipitated product was filtered