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

HRID 454312Notes

Reaction equation

HRID 454312 reaction equation
C[O:2][C:3]1[C:4]([N+:12]([O-:14])=[O:13])=[C:5]2[C:9](=[CH:10][CH:11]=1)[NH:8][CH:7]=[CH:6]2.B(Br)(Br)Br>ClCCl.O>[OH:2][C:3]1[C:4]([N+:12]([O-:14])=[O:13])=[C:5]2[C:9](=[CH:10][CH:11]=1)[NH:8][CH:7]=[CH:6]2

Participants

5

Reactant 2

HCID 25134Boron tribromideHCID 156921715-Methoxy-4-nitro-1H-indole

Product 1

HCID 156921694-nitro-1H-indol-5-olYield 67%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6344DichloromethaneSolvent3×

Procedure

A solution of 5-methoxy-4-nitroindole (110 mg, 0.57 mmol) in dichloromethane (12 ml) was cooled to −30° C. under an atmosphere of nitrogen. Boron tribromide (0.74 ml of a 1M solution in dichloromethane, 0.74 mmol) was added dropwise then the mixture warmed to ambient temperature and stirred for 1 hour. The mixture was cooled to 5° C., diluted with dichloromethane (5 ml), and water (10 ml). After stirring for 5 minutes the insoluble material was filtered off and the dichloromethane layer separated, dried (MgSO4), and evaporated to give a dark oil which was and purified by silica column chromatography eluting with dichloromethane to give 5-hydroxy-4-nitroindole (68 mg, 67%).

Workup

  1. temperatureThe mixture was cooled to 5° C.
  2. stirringAfter stirring for 5 minutes the insoluble material
  3. filtrationwas filtered off
  4. customthe dichloromethane layer separated
  5. dry with materialdried (MgSO4)
  6. customevaporated
  7. customto give a dark oil which
  8. custompurified by silica column chromatography
  9. washeluting with dichloromethane

Sources & evidence

ORD record
ord-f2cdd08e3f40414bb328906f89c6c31a
Source dataset
uspto-grants-2013_07
Patent number
US08492560B2

Reaction notes

Loading…