反应详情

Commercially available ethyl 5-amino-1H-pyrazole-4-carboxylate (5.0 g, 32 mmol) was taken into glacial acetic acid (3.2 mL) followed by addition of ethyl 3-oxo-3-phenylpropanoate (6.1 mL, 35 mmol) and the mixture was refluxed for 12 h. The mixture was allowed to cool to room temperature and concentrated in vacuo. The crude solid was recrystallized (ethanol) and collected to yield 3.1 g (61%) of crystalline ethyl 7-hydroxy-5-phenylpyrazolo[1,5-a]pyrimidine-3-carboxylate. 1H NMR (400 MHz, d6-DMSO): 11.75 (s, 1H), 8.28 (s, 1H), 7.80 (m, 2H), 7.61 (m, 3H), 6.28 (s, 1H), 4.31 (q, 2H), 1.34 (t, 3H).

1. temperaturethe mixture was refluxed for 12 h
2. concentrationconcentrated in vacuo
3. customThe crude solid was recrystallized (ethanol)
4. customcollected