Phosphorus oxychloride → 2-Chloro-7-(1-ethylpropyl)-4-methoxy-1-methyl-1H-benzimidazole
Reaktionsgleichung
[CH2:1]([CH:3]([C:6]1[C:11]2[N:12]([CH3:16])[C:13](=O)[NH:14][C:10]=2[C:9]([O:17][CH3:18])=[CH:8][CH:7]=1)[CH2:4][CH3:5])[CH3:2].P(Cl)(Cl)([Cl:21])=O>>[Cl:21][C:13]1[N:12]([CH3:16])[C:11]2[C:6]([CH:3]([CH2:4][CH3:5])[CH2:1][CH3:2])=[CH:7][CH:8]=[C:9]([O:17][CH3:18])[C:10]=2[N:14]=1Komponenten
3
Reaktionsbedingungen
- Temperatur
- 110 °C
Versuchsvorschrift
A mixture of 7-(1-ethylpropyl)-4-methoxy-1-methyl-1,3-dihydro-2H-benzimidazol-2-one (190 mg, 0.765 mmol) in phosphorous oxychloride (2.14 mL) was stirred at 110° C. for 6 h. The reaction was allowed to cool to room temperature and concentrated in vacuo. The residue was dissolved in ethyl acetate and washed with aqueous sodium bicarbonate and brine. The organic layer was dried over magnesium sulfate, filtered, and concentrated in vacuo. The residue was purified by column chromatography on silica gel (n-hexane/ethyl acetate 10:1-1:1) and crystallized from ethyl acetate/n-hexane to afford the title compound as colorless crystals (123 mg, 60%).