Boron tribromide → Ethyl 3-(1-(4-bromobenzyl)-6-hydroxy-1H-benzo[d]imidazol-2-yl)-2,2-dimethylpropanoate

HRID 1848700Notes

Reaction equation

B(Br)(Br)Br.[Br:5][C:6]1[CH:32]=[CH:31][C:9]([CH2:10][N:11]2[C:15]3[CH:16]=[C:17]([O:20]C)[CH:18]=[CH:19][C:14]=3[N:13]=[C:12]2[CH2:22][C:23]([CH3:30])([CH3:29])[C:24]([O:26][CH2:27][CH3:28])=[O:25])=[CH:8][CH:7]=1>C(Cl)Cl>[Br:5][C:6]1[CH:7]=[CH:8][C:9]([CH2:10][N:11]2[C:15]3[CH:16]=[C:17]([OH:20])[CH:18]=[CH:19][C:14]=3[N:13]=[C:12]2[CH2:22][C:23]([CH3:29])([CH3:30])[C:24]([O:26][CH2:27][CH3:28])=[O:25])=[CH:31][CH:32]=1

Participants

Conditions

Temperature: 5 °C

Procedure

A solution of boron tribromide (3.1 mL, 1 M in DCM) was added drop-wise to a 100 mL round bottomed flask containing ethyl 3-(1-(4-bromobenzyl)-6-methoxy-1H-benzo[d]imidazol-2-yl)-2,2-dimethylpropanoate (700 mg, 1.6 mmol) and DCM (30 mL) at −78° Celsius. The resulting solution was allowed to warm to 5° Celsius over 3 h and partitioned with sat. NaHCO3 (50 mL). The aqueous layer was extracted with DCM (3×25 mL). The combine organic layers were dried with sodium sulfate, filtered, and concentrated to dryness. The residue was subjected to FCC to give the title compound (410 mg, 60%). MS (ESI): mass calcd. for C21H23BrN2O3, 430.08; m/z found, 431.0 [M+H]+.

Workup

custompartitioned with sat. NaHCO3 (50 mL)
extractionThe aqueous layer was extracted with DCM (3×25 mL)
dry with materialThe combine organic layers were dried with sodium sulfate
filtrationfiltered
concentrationconcentrated to dryness

Sources & evidence

ORD record: ord-2841c41c171040cfa19655b4fcd06d04
Source dataset: uspto-grants-2015_02
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08952177B2

Reaction notes

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