Tribromoborane-methyl sulfide → 1-Methyl-2-(methylamino)-1H-benzo[d]imidazol-4-ol

HRID 636512Notes

Reaction equation

HRID 636512 reaction equation
C([O:8][C:9]1[C:17]2[N:16]=[C:15]([NH:18][CH3:19])[N:14]([CH3:20])[C:13]=2[CH:12]=[CH:11][CH:10]=1)C1C=CC=CC=1.[B-](Br)(Br)(Br)[S+](C)C.C(Cl)(Cl)Cl.CO>ClCCl>[OH:8][C:9]1[C:17]2[N:16]=[C:15]([NH:18][CH3:19])[N:14]([CH3:20])[C:13]=2[CH:12]=[CH:11][CH:10]=1

Participants

5

Reactant 3

HCID 4181510Tribromoborane-methyl sulfideHCID 106594804-benzyloxy-1-methyl-2-methylamino-1H-benzimidazoleHCID 21584188Chloroform methanol

Product 1

HCID 108211861-Methyl-2-(methylamino)-1H-benzo[d]imidazol-4-olYield 49.3%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a suspension of 4-benzyloxy-1-methyl-2-methylamino-1H-benzimidazole (150 mg) in dichloromethane (2 ml) was added boron tribromide—methyl sulfide complex (211 mg) in dryice-aceton bath, and the mixture was stirred for 1 hour under ice-cooling and then at ambient temperature overnight. To the reaction mixture were added chloroform—methanol (3:1, v/v) and saturated sodium bicarbonate solution, and insoluble material was filtered off. The separated organic layer was concentrated in vacuo. The residue was purified by preparative thin layer chromatography (chloroform:methanol=8:1, v/v) to give 4-hydroxy-1-methyl-2-methylamino-1H-benzimidazole (49 mg).

Workup

  1. temperaturecooling
  2. customat ambient temperature
  3. customovernight
  4. filtrationv/v) and saturated sodium bicarbonate solution, and insoluble material was filtered off
  5. concentrationThe separated organic layer was concentrated in vacuo
  6. customThe residue was purified by preparative thin layer chromatography (chloroform

Sources & evidence

ORD record
ord-7ca9da831ca94625ac21bc24943093ed
Source dataset
uspto-grants-2001_02
Patent number
US06194396B1

Reaction notes

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