Boron tribromide → 4-methyl-1H-indol-5-ol

HRID 45145

Reaction equation

HRID 45145 reaction equation
C[O:2][C:3]1[C:4]([CH3:12])=[C:5]2[C:9](=[CH:10][CH:11]=1)[NH:8][CH:7]=[CH:6]2.B(Br)(Br)Br.C(=O)(O)[O-].[Na+]>C(Cl)Cl>[CH3:12][C:4]1[C:3]([OH:2])=[CH:11][CH:10]=[C:9]2[C:5]=1[CH:6]=[CH:7][NH:8]2

Participants

5

Reactant 3

HCID 25134Boron tribromideHCID 516892Sodium BicarbonateHCID 32962425-Methoxy-4-methylindole

Product 1

HCID 216912444-methyl-1H-indol-5-ol

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Conditions

Temperature
0 °C

Procedure

5-Methoxy-4-methyl-1H-indole (10 g, 62.0 mmol) is dissolved in DCM (400 mL) and cooled to 0° C. BBr3 (155 mL, 155 mmol) is added dropwise over 1 hour and the black mixture is allowed to warm to room temperature overnight (17 hours). The reaction is poured over a mixture of ice and sodium bicarbonate (aq) solution and extracted with ethyl acetate (1.5 L) and concentrated to a black oil. The oil is absorbed onto silica and separated via FCC (0-50% ethyl acetate:heptanes) to obtain the title compound as a solid. MS (ESI) m/z 148.23 (M+1).

Workup

  1. temperatureto warm to room temperature overnight (17 hours)
  2. extractionextracted with ethyl acetate (1.5 L)
  3. concentrationconcentrated to a black oil
  4. customThe oil is absorbed onto silica
  5. customseparated via FCC (0-50% ethyl acetate:heptanes)

Sources & evidence

ORD record
ord-191d2f4148c141ae8c91cc9f7f567cfc
Source dataset
uspto-grants-2013_09
Patent number
US08541432B2

Linked notes

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