Boron tribromide → 2-Bromo-1,3-benzothiazol-6-ol

HRID 1698095Notes

Reaction equation

HRID 1698095 reaction equation
[Br:1][C:2]1[S:3][C:4]2[CH:10]=[C:9]([O:11]C)[CH:8]=[CH:7][C:5]=2[N:6]=1.CN(C)C1N=CC(C2SC3C=C(O)C=CC=3N=2)=CN=1.B(Br)(Br)Br>CO>[Br:1][C:2]1[S:3][C:4]2[CH:10]=[C:9]([OH:11])[CH:8]=[CH:7][C:5]=2[N:6]=1

Participants

5

Reactant 3

HCID 25134Boron tribromideHCID 112187652-Bromo-6-methoxy-1,3-benzothiazoleHCID 248040662-[2-(Dimethylamino)pyrimidin-5-yl]-1,3-benzothiazol-6-ol

Product 1

HCID 451167822-Bromo-1,3-benzothiazol-6-olYield 76.7%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

2-Bromo-6-methoxy-1,3-benzothiazole (0.832 g, 3.41 mmol) was subjected to the procedure used for the preparation of 2-[2-(dimethylamino)pyrimidin-5-yl]-1,3-benzothiazol-6-ol, with the following exceptions: 4.4 equiv BBr3-solution was used, and after being stirred on, the mixture was poured into MeOH and then concentrated under reduced pressure. A slurry of this residue in EtOAc was filtered through silica and eluted with EtOAc/DCM/MeOH 10:10:1 and DCM/MeOH 9:1. The crude product was recrystallized from EtOAc to give 2-bromo-1,3-benzothiazol-6-ol (0.602 g). 1H NMR δ 10.00 (br s, 1H) 7.77 (d, 1H) 7.39 (d, 1H) 6.97 (dd, 1H).

Workup

  1. concentrationconcentrated under reduced pressure
  2. filtrationA slurry of this residue in EtOAc was filtered through silica
  3. washeluted with EtOAc/DCM/MeOH 10:10:1 and DCM/MeOH 9:1
  4. customThe crude product was recrystallized from EtOAc

Sources & evidence

ORD record
ord-d12c267d4e1f43e59e2c3bd24af5a4b9
Source dataset
uspto-grants-2012_04
Patent number
US08163928B2

Reaction notes

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