反应详情

温度

100 °C

The mixture of ethyl 4-[7-(1-ethylpropyl)-2-oxo-2,3-dihydro-1H-benzimidazol-1-yl]butanoate (Reference Example 31; 1.94 g, 6.09 mmol) and phosphorus oxychloride (4.33 mL) was stirred at 100° C. for 2.5 hr. After cooling, the mixture was poured into ice water and neutralized with sodium hydrogen carbonate. The precipitate was removed by filtration and the filtrate was extracted with ethyl acetate (×3). The combined organic layer was washed with brine, dried over anhydrous magnesium sulfate, filtered and concentrated in vacuo. The residue was purified by silica gel column chromatography eluting with a 0-15% ethyl acetate/n-hexane gradient mixture to give the title compound as a colorless oil (942.6 mg, 2.80 mmol, 46%).

1. temperatureAfter cooling
2. customThe precipitate was removed by filtration
3. extractionthe filtrate was extracted with ethyl acetate (×3)
4. washThe combined organic layer was washed with brine
5. dry with materialdried over anhydrous magnesium sulfate
6. filtrationfiltered
7. concentrationconcentrated in vacuo
8. customThe residue was purified by silica gel column chromatography
9. washeluting with a 0-15% ethyl acetate/n-hexane gradient mixture