Boron tribromide → 1-Methyl-1H-benzo[d]imidazol-5-ol

HRID 1777129Notes

Reaction equation

HRID 1777129 reaction equation
C[O:2][C:3]1[CH:12]=[CH:11][C:6]2[N:7]([CH3:10])[CH:8]=[N:9][C:5]=2[CH:4]=1.B(Br)(Br)Br>C(Cl)Cl>[CH3:10][N:7]1[C:6]2[CH:11]=[CH:12][C:3]([OH:2])=[CH:4][C:5]=2[N:9]=[CH:8]1

Participants

4

Reactant 2

HCID 25134Boron tribromideHCID 42927805-Methoxy-1-methylbenzimidazole

Product 1

HCID 8404451-Methyl-1H-benzo[d]imidazol-5-olYield 21.9%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Conditions

Temperature
0 °C

Procedure

To a solution of 5-methoxy-1-methyl-1H-benzo[d]imidazole (500 mg, 3.08 mmol) in CH2Cl2 (6 ml) was added BBr3 (3.1 g, 12.33 mmol) dropwise at 0° C. After addition, the mixture was stirred for 2 h at 0° C. The mixture was then quenched by slow addition to ice water (50 mL). The resulting mixture was extracted with CH2Cl2 (2×20 mL). The combined organic layers were washed with brine (30 mL), dried over Na2SO4 and concentrated to give the title compound (100 mg, 21.9%) as a white solid which was used in next step without further purification. LCMS (m/z): 149.1 (M+1).

Workup

  1. additionAfter addition
  2. customThe mixture was then quenched by slow addition to ice water (50 mL)
  3. extractionThe resulting mixture was extracted with CH2Cl2 (2×20 mL)
  4. washThe combined organic layers were washed with brine (30 mL)
  5. dry with materialdried over Na2SO4
  6. concentrationconcentrated

Sources & evidence

ORD record
ord-7644576b56744519a821b874e5e5abf8
Source dataset
uspto-grants-2016_02
Patent number
US09266836B2

Reaction notes

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