3-Chlorophenylboronic acid synthesis

9synthesis methods

Product Name:3-Chlorophenylboronic acid
CAS Number:63503-60-6
Molecular formula:C6H6BClO2
Molecular Weight:156.37

Using m-dichlorobenzene as the starting material, iodine particles and 1,2-dibromoethane as the initiator reacts with magnesium in an organic solvent to prepare 3-chlorophenyl magnesium chloride. Then, the trimethyl borate is reacted with an organic solvent to prepare 3-chlorophenyl borate dimethyl ester. Finally, the product 3-chlorophenylboronic acid is obtained through hydrolysis, extraction, and crystallization.

108-37-2
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63503-60-6
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Yield:63503-60-6 57%

Reaction Conditions:

Stage #1:1-bromo-3-chlorobenzene with n-butyllithium in tetrahydrofuran;hexaneInert atmosphere;
Stage #2: with Trimethyl borate in tetrahydrofuran;hexaneInert atmosphere;

Steps:

General procedure for the synthesis of arylboronic acids
General procedure: Under an argon atmosphere a solution of the appropriate bromobenzene (1 equivalent) dissolved in anhydrous THF (approximately 30 mL per mmol bromobenzene) is cooled to -78 °C using a nitrogen-ethanol-bath. A solution of 2.3 equivalents of n-butyllithium in hexane is added drop wise keeping the temperature below -78 °C. After completion the mixture is stirred for one hour at this temperature. Then 1.5 equivalents of trimethyl borate are added slowly and the reaction mixture is stirred at -78 °C for another hour. The cooling bath is then removed, the reaction mixture is stirred until room temperature is reached and quenched with a saturated solution of ammonium chloride. THF and the major part of the water is removed under reduced pressure, the residue is laced with 3M hydrochloric acid until a pH of 3 is reached. After extraction with DCM (3 x) the organic phases are collected, washed with brine, dried over sodium sulphate and filtered. DCM is removed under reduced pressure, the resulting solid is washed first with ice cold water and then with PE and dried.

References:

Obermoser, Victoria;Mauersberger, Robert;Schuster, Daniela;Czifersky, Monika;Lipova, Marina;Siegl, Monika;Kintscher, Ulrich;Gust, Ronald [European Journal of Medicinal Chemistry,2017,vol. 126,p. 590 - 603] Location in patent:supporting information

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108-37-2
350 suppliers
$6.00/10g