反应详情

To acetic anhydride (4.7 ml) under ice cooling, formic acid (4.7 ml) was added dropwise, to which 2-aminothiophene-3-carboxylic acid ethyl ester (2.8 g, 16.4 mmol) was added and stirred at room temperature for 2 hours. After the solvent was distilled off under reduced pressure, ether was added, and the precipitate that deposited was filtered off. Ether was distilled off under reduced pressure to obtain 2-formylaminothiophene-3-carboxylic acid ethyl ester (3.0 g, 15.3 mmol).

1. additionwas added
2. distillationAfter the solvent was distilled off under reduced pressure, ether
3. additionwas added
4. filtrationthe precipitate that deposited was filtered off
5. distillationEther was distilled off under reduced pressure