Hydrochloric Acid → 3-Chloro-4-(cyclopropylsulfonyl)phenylboronic acid

Participants

Reaction Conditions

Reaction Steps

n-Butyllithium (1.6 M solution in hexane, 9.2 mL) was added dropwise to a solution of 4-bromo-2-chloro-1-(cyclopropylsulfonyl)benzene obtained in Reference Example 5-30 (1.45 g) and triisopropyl borate (5.54 g) in tetrahydrofuran (15 mL) under cooling at an external temperature of −78° C. in a nitrogen atmosphere, after which the mixture was stirred at the same temperature for three hours. 1 M hydrochloric acid (10 mL) was added and the reaction solution, still basic, was extracted with chloroform. The aqueous layer was made acidic with 1 M hydrochloric acid (10 mL), followed by extraction with chloroform. The solvent was evaporated from the organic layer under reduced pressure to give a crude product of 3-chloro-4-(cyclopropylsulfonyl)phenylboronic acid (1.02 g).

Provenance & Evidence