反应详情

温度

80 °C

A mixture of 3-amino-5-(pyridin-4-yl)thiophene-2-carboxamide (0.108 g, 0.500 mmol), 3-hexanone (2.0 mL), p-toluenesulfonic acid monohydrate (0.0095 g, 0.050 mmol) and acetic acid (2.0 mL) was stirred overnight at 80° C. in a sealed tube. The mixture was poured into sat. aqueous sodium hydrogen carbonate (150 mL). Extraction with ethyl acetate (100 mL), drying over magnesium sulfate, filtration and concentration at reduced pressure gave an oil. This oil was purified by column chromatography (Combiflash, 12 g silica gel, dichloromethane to 90:10 dichloromethane/methanol), then recrystallized from methanol, and the precipitate was collected by filtration. This yellow solid contained methanol, so it was stirred in ethyl acetate (5.0 mL) for 30 min at 70° C. After cooling, the precipitate was collected by filtration to afford the title compound (0.0334 g, 22%) as a yellow solid:

1. extractionExtraction with ethyl acetate (100 mL)
2. dry with materialdrying over magnesium sulfate, filtration and concentration at reduced pressure
3. customgave an oil
4. customThis oil was purified by column chromatography (Combiflash, 12 g silica gel, dichloromethane to 90:10 dichloromethane/methanol)
5. customrecrystallized from methanol
6. filtrationthe precipitate was collected by filtration
7. stirringso it was stirred in ethyl acetate (5.0 mL) for 30 min at 70° C
8. temperatureAfter cooling
9. filtrationthe precipitate was collected by filtration