Diisopropylethylamine → 1-[2-(5-Fluorobenzimidazol-2-ylthio)ethyl]-4-formylpiperazine

HRID 1354260Notes

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].[F:12][C:13]1[CH:22]=[CH:21][C:16]2[N:17]=[C:18]([SH:20])[NH:19][C:15]=2[CH:14]=1.C(N(C(C)C)CC)(C)C.[I-].C(C[P+](C)(C)C)#N>C(#N)CC.O>[F:12][C:13]1[CH:22]=[CH:21][C:16]2[N:17]=[C:18]([S:20][CH2:10][CH2:9][N:6]3[CH2:7][CH2:8][N:3]([CH:1]=[O:2])[CH2:4][CH2:5]3)[NH:19][C:15]=2[CH:14]=1

Participants

Conditions

Temperature: 92 °C

Procedure

1-Formyl-4-(2-hydroxyethyl)piperazine (1.20 g, 7.6 mmol), 5-fluoro-2-mercaptobenzimidazole (1.28 g, 7.6 mmol), and diisopropylethylamine (3.93 g, 30.4 mmol) was dissolved in propionitrile (50 mL), and cyanomethyltrimethylphosphonium iodide (7.39 g, 30.4 mmol) was added to the mixture, followed by stirring for one hour at 92° C. under argon. The reaction mixture was allowed to cool and then poured into water (100 mL), followed by extraction with chloroform (100 mL×3) The resultant organic layer was washed with saturated brine and then dried over sodium sulfate anhydrate, followed by concentration under reduced pressure. The crude product was crystallized from acetone-ether, to thereby yield 1-[2-(5-fluorobenzimidazol-2-ylthio)ethyl]-4-formylpiperazine (1.87 g, yield 80%) as a brown crystalline powder.

Workup

temperatureto cool
extractionfollowed by extraction with chloroform (100 mL×3) The resultant organic layer
washwas washed with saturated brine
dry with materialdried over sodium sulfate anhydrate
concentrationfollowed by concentration under reduced pressure
customThe crude product was crystallized from acetone-ether

Sources & evidence

ORD record: ord-27a4d1b7b6ce4a5a8e5779686c918492
Source dataset: uspto-grants-2007_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07223764B2

Reaction notes

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