Diisopropylethylamine → 1-[2-(5,6-Difluorobenzimidazol-2-ylthio)ethyl]-4-formylpiperazine

Participants

Reaction Conditions

Reaction Steps

1-Formyl-4-(2-hydroxyethyl)piperazine (1.11 g, 7.0 mmol), 5,6-difluoro-2-mercaptobenzimidazole (1.30 g, 7.0 mmol), and diisopropylethylamine (3.62 g, 28.0 mmol) were dissolved in propionitrile (50 mL), and cyanomethyltrimethylphosphonium iodide (6.80 g, 28.0 mmol) was added thereto, followed by stirring for one hour at 92° C. under argon. The reaction mixture was allowed to cool and then poured in water (100 mL), followed by extraction with chloroform (100 mL×3). The organic layer was washed with saturated brine and then dried over sodium sulfate anhydrate, and the product was concentrated under reduced pressure. The crude product was crystallized from acetone-ether, to thereby yield 1-[2-(5,6-difluorobenzimidazol-2-ylthio)ethyl]-4-formylpiperazine (1.78 g, yield 78%) as a yellow crystalline powder.

Provenance & Evidence