ChemicalBook CAS DataBase List 2,4-Dimethoxybenzeneboronic acid

2,4-Dimethoxybenzeneboronic acid synthesis

5synthesis methods

Product Name:2,4-Dimethoxybenzeneboronic acid
CAS Number:133730-34-4
Molecular formula:C8H11BO4
Molecular Weight:181.98

17715-69-4

133730-34-4

The general procedure for the synthesis of 2,4-dimethoxyphenylboronic acid from 2,4-dimethoxybromobenzene was as follows: first, 576 μL of 1-bromo-2,4-dimethoxybenzene was dissolved in 5.8 mL of tetrahydrofuran, which was cooled to -78 °C under argon protection. Subsequently, 3 mL of 1.6 mol/L n-butyllithium hexane solution was slowly added dropwise. After the dropwise addition, 1.1 mL of triisopropyl borate was added and the reaction continued to be stirred at -78 °C for 40 minutes, after which it was brought to room temperature and stirred for 2 hours. Upon completion of the reaction, the reaction mixture was quenched by adding 40 mL of water and 1 mL of 5N hydrochloric acid to the reaction mixture and then extracted with 50 mL of ethyl acetate. The organic layer was dried with anhydrous magnesium sulfate and the solvent was removed by distillation under reduced pressure. Finally, 610.2 mg of 2,4-dimethoxyphenylboronic acid was purified by silica gel column chromatography (eluent ratio hexane:ethyl acetate=2:1). The product was characterized by 1H-NMR (CDCl3): δ (ppm) 3.85 (3H, s), 3.89 (3H, s), 5.81 (2H, s), 6.46 (1H, s), 6.56 (1H, dd, J = 2.0,8.4 Hz), 7.77 (1H, d, J = 8.4 Hz).

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17715-69-4
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133730-34-4
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Yield:133730-34-4 610.2mg

Reaction Conditions:

Stage #1: Triisopropyl borate;1-Bromo-2,4-dimethoxybenzenewith n-butyllithium in tetrahydrofuran;hexane;water at -78 - 40; for 2.66667 h;Inert atmosphere;
Stage #2: with hydrogenchloride in tetrahydrofuran;hexane;water;

Steps:

33.a a) 2,4-Dimethoxyphenylboronic acid

a)
2,4-Dimethoxyphenylboronic acid
576 μl of 1-bromo-2,4-dimethoxybenzene was dissolved in 5.8 ml of tetrahydrofuran and 3 ml of 1.6 mol/l solution of n-butyl lithium in hexane was added dropwise at -78° C. under argon atmosphere.
Then, 1.1 ml of triisopropylborate was added, and after stirred at -78° C. for 40 minutes, the mixture was stirred at room temperature for 2 hours.
To the reaction mixture, 40 ml of water and 1 ml of 5N-hydrochloric acid was added, and extracted with 50 ml of ethyl acetate.
After the organic layer was dried over anhydrous magnesium sulfate, the solvent was distilled off under reduced pressure, and purified by silica gel column chromatography (hexane:ethyl acetate=2:1) to yield 610.2 mg of the title compound.
¹H-NMR (CDCl₃); δ (ppm) 3.85 (3H, s), 3.89 (3H, s), 5.81 (2H, s), 6.46 (1H, s), 6.56 (1H, dd, J=2.0, 8.4 Hz), 7.77 (1H, d, J=8.4 Hz).

References:

US2013/317074,2013,A1 Location in patent:Paragraph 0482; 0483; 0484

17715-69-4
301 suppliers
$9.00/10g

133730-34-4
299 suppliers
$6.00/1g

References

67-56-1 Synthesis