Diisopropylethylamine → 1-Formyl-4-[2-(benzimidazol-2-ylthio)ethyl]piperazine

HRID 890827Notes

Reaction equation

HRID 890827 reaction equation
[CH:1]([N:3]1[CH2:8][CH2:7][N:6]([CH2:9][CH2:10]O)[CH2:5][CH2:4]1)=[O:2].[SH:12][C:13]1[NH:14][C:15]2[CH:21]=[CH:20][CH:19]=[CH:18][C:16]=2[N:17]=1.C(N(CC)C(C)C)(C)C.[I-].C(C[P+](C)(C)C)#N>C(#N)CC.O>[CH:1]([N:3]1[CH2:8][CH2:7][N:6]([CH2:9][CH2:10][S:12][C:13]2[NH:14][C:15]3[CH:21]=[CH:20][CH:19]=[CH:18][C:16]=3[N:17]=2)[CH2:5][CH2:4]1)=[O:2]

Participants

7

Reactant 4

HCID 81531DiisopropylethylamineHCID 99422134-(2-Hydroxyethyl)piperazine-1-carbaldehydeHCID 10514344(Cyanomethyl)trimethylphosphanium iodideHCID 178527775HCID 178527775, compound

Product 1

HCID 99617881-Formyl-4-[2-(benzimidazol-2-ylthio)ethyl]piperazineYield 86.1%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 7854PropionitrileSolvent

Procedure

To a solution containing 1-formyl-4-(2-hydroxyethyl)piperazine (1.90 g, 12 mmol), 2-mercaptobenzimidazole (1.50 g, 10 mmol), and N,N-diisopropylethylamine (1.80 g, 14 mmol) in propionitrile (16 mL), cyanomethyltrimethylphosphonium iodide (2.80 g, 11.5 mmol) was added under argon, and the mixture was refluxed for 2 hours. After cooling, the reaction mixture was poured into water (100 mL), and the liquid was subjected to extraction with chloroform (100 mL×3) . The organic layer was washed with saturated brine, followed by drying over sodium sulfate anhydrate and removing the solvent through filtration. The thus-formed crude product was crystallized from acetone-diethyl ether, thereby yielding 2.50 g of 1-formyl-4-[2-(benzimidazol-2-ylthio)ethyl]piperazine (yield: 86%) as a colorless crystalline powder.

Workup

  1. additionwas added under argon
  2. temperaturethe mixture was refluxed for 2 hours
  3. temperatureAfter cooling
  4. extractionthe liquid was subjected to extraction with chloroform (100 mL×3)
  5. washThe organic layer was washed with saturated brine
  6. dry with materialby drying over sodium sulfate anhydrate
  7. customremoving the solvent
  8. filtrationthrough filtration
  9. customThe thus-formed crude product
  10. customwas crystallized from acetone-diethyl ether

Sources & evidence

ORD record
ord-f8a06442bfd246029a215d279bc017e9
Source dataset
uspto-grants-2006_02
Patent number
US06998486B2

Reaction notes

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