反应详情

温度

80 °C

To a suspension of tert-butyl 5-nitrothiophene-2-carboxylate (Int. 54) (2.230 g, 9.73 mmol) in a mixture of EtOH (60 ml) and water (30 ml), iron powder (3.26 g, 58.4 mmol) and ammonium chloride (0.364 g, 6.81 mmol) were added. The reaction was stirred at 80° C. for 3 hours and then at RT overnight. The mixture was filtered through a celite pad and the filtrate was evaporated to dryness. The crude was then dissolved in EtOAc and washed with brine; the organic phase was dried over sodium sulfate and the solvent evaporated under vacuum. The residue was purified by filtration through a silica gel cartridge (petroleum ether/EtOAc=9/1 to 6/4) to yield tert-butyl 5-aminothiophene-2-carboxylate (Int. 55) (1.481 g, 7.43 mmol, MS/ESI+200.0 [MH]+).

1. additionwere added
2. customat RT
3. customovernight
4. filtrationThe mixture was filtered through a celite pad
5. customthe filtrate was evaporated to dryness
6. dissolutionThe crude was then dissolved in EtOAc
7. washwashed with brine
8. dry with materialthe organic phase was dried over sodium sulfate
9. customthe solvent evaporated under vacuum
10. filtrationThe residue was purified by filtration through a silica gel cartridge (petroleum ether/EtOAc=9/1 to 6/4)