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ChemicalBook CAS DataBase List 2,4-Dimethoxybenzeneboronic acid
133730-34-4

2,4-Dimethoxybenzeneboronic acid synthesis

5synthesis methods
-

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

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