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

HRID 70688Notes

Reaction equation

C([Li])CCC.Br[C:7]1[CH:12]=[CH:11][C:10]([S:13]([CH:16]2[CH2:18][CH2:17]2)(=[O:15])=[O:14])=[C:9]([Cl:19])[CH:8]=1.[B:20](OC(C)C)([O:25]C(C)C)[O:21]C(C)C.Cl>O1CCCC1>[Cl:19][C:9]1[CH:8]=[C:7]([B:20]([OH:25])[OH:21])[CH:12]=[CH:11][C:10]=1[S:13]([CH:16]1[CH2:18][CH2:17]1)(=[O:15])=[O:14]

Participants

Conditions

Temperature: -78 °C

Procedure

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).

Workup

extractionthe reaction solution, still basic, was extracted with chloroform
extractionfollowed by extraction with chloroform
customThe solvent was evaporated from the organic layer under reduced pressure

Sources & evidence

ORD record: ord-2cef8486ac064fdf91af2336ed5ae8d7
Source dataset: uspto-grants-2014_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08822503B2

Reaction notes

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