Ammonium thiocyanate → 1022151-32-1

HRID 1890913Notes

Reaction equation

HRID 1890913 reaction equation
[Br:1][C:2]1[CH:8]=[CH:7][C:5]([NH2:6])=[CH:4][C:3]=1[F:9].[S-:10][C:11]#[N:12].[NH4+].BrBr>CC(O)=O>[Br:1][C:2]1[C:3]([F:9])=[CH:4][C:5]2[N:6]=[C:11]([NH2:12])[S:10][C:7]=2[CH:8]=1

Participants

5

Reactant 3

HCID 15666Ammonium thiocyanateHCID 24408BromineHCID 8218484-Bromo-3-fluoroaniline

Product 1

HCID 754809671022151-32-1Yield 57%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent2×

Procedure

To a solution of 4-bromo-3-fluoro-aniline (3.68 g, 19.37 mmol) in glacial AcOH (40 mL) was added ammonium thiocyanate (2.95 g, 38.74 mmol). When the reaction mixture was almost clear, it was placed in a cold water bath and a solution of bromine (3.1 g, 19.37 mmol) in glacial AcOH (10 mL) was added dropwise over a 10 min period. The reaction mixture was stirred at room temperature for 1 h, then it was concentrated in vacuo. The residue was partitioned between 1 N aqueous KOH and ethyl acetate. The aqueous layer was further extracted with ethyl acetate, and the combined organic layers were adsorbed on silica gel. Purification by flash chromatography on silica gel using a gradient of 0-70% ethyl acetate/hexane afforded 2.73 g of 6-bromo-5-fluoro-benzothiazol-2-ylamine as a light yellow solid (57% yield): 1H NMR (DMSO-d6) δ 7.29 (d, 1H), 7.78 (broad s, 2H), 7.99 (d, 1H); MS (m/z) 247, 249 [M+H+]+.

Workup

  1. customit was placed in a cold water bath
  2. concentrationit was concentrated in vacuo
  3. customThe residue was partitioned between 1 N aqueous KOH and ethyl acetate
  4. extractionThe aqueous layer was further extracted with ethyl acetate
  5. customPurification by flash chromatography on silica gel using a gradient of 0-70% ethyl acetate/hexane

Sources & evidence

ORD record
ord-112516d17a7f41e6a46f9ac90636a188
Source dataset
uspto-grants-2013_08
Patent number
US08507489B2

Reaction notes

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