4-(NAPHTHALEN-1-YL)PHENYLBORONIC ACID synthesis

Yield:870774-25-7 67%

Reaction Conditions:

Stage #1: 1-(4-bromo-phenyl)-naphthalenewith n-butyllithium in tetrahydrofuran;hexane at -60; for 2 h;Inert atmosphere;
Stage #2: with Triisopropyl borate in tetrahydrofuran;hexane at -60 - 20; for 17 h;Inert atmosphere;
Stage #3: with hydrogenchloride in tetrahydrofuran;hexane;water at 20; for 1 h;

Steps:

4.2 [Synthesis Reference 4-2] Synthesis of 4-(1-naphthyl)phenylboronic acid

Under an argon gas atmosphere, a mixture of 208.8 g (737.4 mmol) of 1-(4-bromophenyl)naphthalene and 2.1 L of dehydrated TI-IF was cooled down to minus 60 degree C. Then, 567 ml (884.9 mmol) of hexane solution of 1.56M n-butyllithium was dropped into the mixture while the mixture was being stirred. The reaction mixture was further stirred at minus 60 degrees for 2 hours. 416 g (2.21 mol) of triisopropylborate was dropped into the reaction mixture at minus 60 degrees C. The reaction mixture was then stirred at room temperature for 17 hours. The reaction mixture was added with aqueous solution of hydrochloric acid and stirred at room temperature for 1 hour. After the reaction, the reaction mixture was added with toluene, and aqueous phase thereof was eliminated. Then, organic phase thereof was dried with magnesium sulfate, and the solvent was distilled away under reduced pressure. By recrystallizing the obtained solid by toluene, 126 g of 4-(1-naphthyl)phenylboronic acid was obtained at an yield of 67%.

References:

US2010/331585,2010,A1 Location in patent:Page/Page column 96-97