Potassium Phosphate, Tribasic → 3-(3-Methyl-3H-imidazol-4-yl)-phenylboronic acid

HRID 2234840Notes

Reaction equation

[C:1]1(B(O)O)[CH:6]=[CH:5][CH:4]=[C:3]([B:7]([OH:9])[OH:8])[CH:2]=1.Br[C:14]1[N:18]([CH3:19])[CH:17]=[N:16][CH:15]=1.P([O-])([O-])([O-])=O.[K+].[K+].[K+].C1(P(C2CCCCC2)C2C=CC=CC=2C2C=CC=CC=2N(C)C)CCCCC1>C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.C1C=CC(/C=C/C(/C=C/C2C=CC=CC=2)=O)=CC=1.[Pd].[Pd].CC(N(C)C)=O>[CH3:19][N:18]1[C:14]([C:1]2[CH:2]=[C:3]([B:7]([OH:9])[OH:8])[CH:4]=[CH:5][CH:6]=2)=[CH:15][N:16]=[CH:17]1

Participants

Conditions

Temperature: 130 °C

Procedure

1,3-Benzenediboronic acid (300 mg, 1.8 mmol), 5-bromo-1-methylimidazole (291 mg, 1.8 mmol), potassium phosphate (1.15 g, 5.4 mmol), tris(dibenzylideneacetone)dipalladium(0) (164 mg, 0.18 mmol), and 2-dicyclohexylphosphino-2′-(N,N-dimethylamino)biphenyl (142 mg, 0.36 mmol) were combined with DMA (3 mL) in a sealed tube purged with N2. The reaction was heated at 130° C. for 25 min in a microwave reactor. The solution was diluted with MeOH, filtered, and concentrated in vacuo. Purification by preparatory HPLC gave 166 mg (45%) of the title compound as a white solid. 1H NMR (400 MHz, DMSO-d6) δ 9.12 (s, 1H), 7.91-7.98 (m, 2H), 7.83 (s, 1H), 7.63 (d, J=7.6 Hz, 1H), 7.52 (t, J=7.6 Hz, 1H), 3.83 (s, 3H). [M+H] calc'd for C10H11BN2O2, 202; found, 202.

Workup

custompurged with N2
additionThe solution was diluted with MeOH
filtrationfiltered
concentrationconcentrated in vacuo
customPurification by preparatory HPLC

Sources & evidence

ORD record: ord-6253588f98f448f6817a2dadeaea74a1
Source dataset: uspto-grants-2010_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07713973B2

Reaction notes

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