反应详情

After adding 25 ml of trifluoroacetic acid to a 50 ml solution of 3.30 g of 3-(N′-t-butoxycarbonylhydrazino)-1H-pyrazole-4-carboxylic acid ethyl ester in dichloromethane, the mixture was stirred for 2 hours at room temperature. Next, 100 ml of toluene was added and the solvent was removed under reduced pressure. The residue was dissolved in a small amount of methanol, and after adding a 4N hydrogen chloride-ethyl acetate solution until the solution reached acidity, the solvent was removed under reduced pressure. The residue was treated with 50 ml of t-butyl methyl ether, and the solid was collected by filtration and dried under reduced pressure to obtain the target compound (3.30 g) as a colorless solid.

1. customthe solvent was removed under reduced pressure
2. dissolutionThe residue was dissolved in a small amount of methanol
3. additionafter adding a 4N hydrogen chloride-ethyl acetate solution until the solution
4. customthe solvent was removed under reduced pressure
5. additionThe residue was treated with 50 ml of t-butyl methyl ether
6. filtrationthe solid was collected by filtration
7. customdried under reduced pressure