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ChemicalBook CAS DataBase List Pyridine-4-boronic acid
1692-15-5

Pyridine-4-boronic acid synthesis

7synthesis methods
4-Bromopyridine

1120-87-2

Trimethyl borate

121-43-7

Water

7732-18-5

Pyridine-4-boronic acid

1692-15-5

Under argon protection, 4-bromopyridine (1.5 g, 10 mmol) was placed in a 200 mL Schlenk flask and 40 mL of anhydrous deoxytetrahydrofuran was added. After cooling the reaction mixture to -78 °C, 5 mL (2.2 M, 11 mmol) of n-butyllithium solution was slowly added dropwise and the reaction was maintained at this temperature for 1 hour. Subsequently, 4 mL of trimethyl borate was added and the reaction continued at -78 °C for 1 hour. Upon completion of the reaction, the mixture was slowly warmed to room temperature and stirred overnight. The reaction was quenched with 2 mol/L hydrochloric acid solution and purified by recrystallization from hexane to give pyridine-4-boronic acid hydrochloride (0.8 g, 65% yield).

-

Yield:1692-15-5 65%

Reaction Conditions:

Stage #1: 4-bromopyridinwith n-butyllithium in tetrahydrofuran at -78; for 1 h;Inert atmosphere;
Stage #2: Trimethyl borate in tetrahydrofuran at -78; for 1 h;Inert atmosphere;
Stage #3: waterwith hydrogenchloride in tetrahydrofuran at 0;Inert atmosphere;

Steps:

7

In the Ar gas protection,4-Bromo-pyridine (1.5 g; 10 mmol) was placed in a 200 ml Schlenk flask,After addition of 40 ml of anhydrous deoxygenated tetrahydrofuran,The reaction mixture was cooled to -78 ° C in a low temperature reactor,5 ml (2.2 M; 11 mmol) of butyllithium was added dropwise,After reaction for 1 h,4 ml of methyl borate was added,Low temperature reaction 1h and removed overnight.The reaction was quenched with 2 mol / L dilute hydrochloric acid,After recrystallization from n-hexane 0.8 g (0.8 g, 65% yield) was obtained.

References:

CN104326980,2016,B Location in patent:Paragraph 0064; 0065

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