Hydrogen Sulfide → 1-Ethyl-5-fluoro-6-[4-methyl-1-piperazinyl]-2-benzimidazolecarbothioamide

HRID 1974629Notes

Reaction equation

HRID 1974629 reaction equation
[CH2:1]([N:3]1[C:7]2[CH:8]=[C:9]([N:13]3[CH2:18][CH2:17][N:16]([CH3:19])[CH2:15][CH2:14]3)[C:10]([F:12])=[CH:11][C:6]=2[N:5]=[C:4]1CC#N)[CH3:2].C([N:25]([CH2:28]C)CC)C.[SH2:30]>N1C=CC=CC=1>[CH2:1]([N:3]1[C:7]2[CH:8]=[C:9]([N:13]3[CH2:14][CH2:15][N:16]([CH3:19])[CH2:17][CH2:18]3)[C:10]([F:12])=[CH:11][C:6]=2[N:5]=[C:4]1[C:28](=[S:30])[NH2:25])[CH3:2]

Participants

5

Reactant 3

HCID 402Hydrogen SulfideHCID 8471TriethylamineHCID 191016981-Ethyl-5-fluoro-6-(4-methyl-1-piperazinyl)-2-benzimidazoleacetonitrile

Product 1

HCID 191016961-Ethyl-5-fluoro-6-[4-methyl-1-piperazinyl]-2-benzimidazolecarbothioamideYield 80%

Reagents, catalysts & solvents 1

HCID 1049PyridineSolvent

Procedure

1-Ethyl-5-fluoro-6-(4-methyl-1-piperazinyl)-2-benzimidazoleacetonitrile (834 mg, 2.77 mmol) is dissolved in pyridine (20 ml) and triethylamine (2.8 g, 27.7 mmol). The solution is cooled to 0°. Subsequently, hydrogen sulfide is introduced during 30 minutes. The thus-obtained deep green solution is heated to 45° for 2 hours. The solvent is distilled off and the residue is dried in a high vacuum and then crystallized from acetonitrile. The crystals are filtered off, dissolved in an ethyl acetate/methanol mixture (10 ml, 1:1) and then chromatographed on silica gel (eluent: ethyl acetate/methanol 6:4). The product is recrystallized from ethyl acetate. There are obtained 745 mg (80%) of 1-ethyl-5-fluoro-6-[4-methyl-1-piperazinyl]-2-benzimidazolecarbothioamide.

Workup

  1. temperatureThe solution is cooled to 0°
  2. temperatureThe thus-obtained deep green solution is heated to 45° for 2 hours
  3. distillationThe solvent is distilled off
  4. customthe residue is dried in a high vacuum
  5. customcrystallized from acetonitrile
  6. filtrationThe crystals are filtered off
  7. dissolutiondissolved in an ethyl acetate/methanol mixture (10 ml, 1:1)
  8. customchromatographed on silica gel (eluent: ethyl acetate/methanol 6:4)
  9. customThe product is recrystallized from ethyl acetate

Sources & evidence

ORD record
ord-4ccfc55e55bd4d039554dd3dafdaf878
Source dataset
uspto-grants-1994_02
Patent number
US05283248

Reaction notes

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