Ammonium thiocyanate → Riluzole

HRID 1966052Notes

Reaction equation

HRID 1966052 reaction equation
[F:1][C:2]([F:12])([F:11])[O:3][C:4]1[CH:10]=[CH:9][C:7]([NH2:8])=[CH:6][CH:5]=1.[S-:13][C:14]#[N:15].[NH4+].[Br-].[Br-].[Br-].C([N+](C)(C)C)C1C=CC=CC=1.C([N+](C)(C)C)C1C=CC=CC=1.C([N+](C)(C)C)C1C=CC=CC=1.C([O-])(O)=O.[Na+]>C(#N)C>[NH2:15][C:14]1[S:13][C:9]2[CH:10]=[C:4]([O:3][C:2]([F:11])([F:12])[F:1])[CH:5]=[CH:6][C:7]=2[N:8]=1

Participants

6

Reactant 4

HCID 15666Ammonium thiocyanateHCID 516892Sodium BicarbonateHCID 6008484-(Trifluoromethoxy)anilineHCID 53442637Benzyltrimethylammoniumtribromide

Product 1

HCID 5070RiluzoleYield 80%

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

To a mixture of 4-trifluoromethoxyaniline (2.07 mmol) and ammonium thiocyanate (2 mmol) in acetonitrile, is added benzyltrimethylammonium tribromide, at room temperature. The reaction is left to proceed while stirring at room temperature for 24 hours; it is then neutralised with NaHCO3 and extracted with CH2Cl2. The combined organic extracts are washed with H2O, dried over Na2SO4, filtered and then evaporated under vacuum. The crude product is purified by chromatography through silica, eluting with petroleum ether/AcOEt (1:1), and a solid obtained that is recrystallised from hexane/ethyl ether to give 2-amino-6-(trifluoromethoxy)-benzothiazole as pale yellow flakes, with a yield of 80%.

Workup

  1. customat room temperature
  2. waitThe reaction is left
  3. extractionextracted with CH2Cl2
  4. washThe combined organic extracts are washed with H2O
  5. dry with materialdried over Na2SO4
  6. filtrationfiltered
  7. customevaporated under vacuum
  8. customThe crude product is purified by chromatography through silica
  9. washeluting with petroleum ether/AcOEt (1:1)
  10. customa solid obtained that
  11. customis recrystallised from hexane/ethyl ether

Sources & evidence

ORD record
ord-ea3037a9ac644e3c89ff05e546eecfed
Source dataset
uspto-grants-2013_04
Patent number
US08420634B2

Reaction notes

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