Trimethyl borate → (4-(1H-imidazol-1-yl)-2-methoxyphenyl)boronic acid

HRID 1027174Notes

Reaction equation

Br[C:2]1[CH:7]=[CH:6][C:5]([N:8]2[CH:12]=[CH:11][N:10]=[CH:9]2)=[CH:4][C:3]=1[O:13][CH3:14].C([Li])CCC.[B:20](OC)([O:23]C)[O:21]C>C1COCC1>[N:8]1([C:5]2[CH:6]=[CH:7][C:2]([B:20]([OH:23])[OH:21])=[C:3]([O:13][CH3:14])[CH:4]=2)[CH:12]=[CH:11][N:10]=[CH:9]1

Participants

Conditions

Temperature: -78 °C

Procedure

To a stirred solution of 1-(4-bromo-3-methoxyphenyl)-1H-imidazole in THF (5 mL) was added 2.5 M n-butyl lithium in hexanes (0.348 ml, 0.869 mmol) dropwise at −78° C. over 15 min. After addition was complete, the reaction solution was stirred at −78° C. for 15 min, and trimethyl borate (0.353 mL, 3.16 mmol) was added. The reaction was allowed to warm to RT, and continued to stir overnight. The reaction was quenched with 1 M HCl aqueous solution to pH 2, diluted with water and extracted with DCM (3×). The product remained in the aqueous solution which was concentrated in vacuo to give crude (4-(1H-imidazol-1-yl)-2-methoxyphenyl)boronic acid (120 mg, MS: 219.2 [M+H+]).

Workup

additionAfter addition
temperatureto warm to RT
stirringto stir overnight
customThe reaction was quenched with 1 M HCl aqueous solution to pH 2
additiondiluted with water
extractionextracted with DCM (3×)
concentrationwas concentrated in vacuo

Sources & evidence

ORD record: ord-72ddd791864547208faa52aa37c0a43f
Source dataset: uspto-grants-2014_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08729263B2

Reaction notes

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