反应详情

A solution of 69.1 g of 4-(2-chloronicotinoyl)-2,6-di-tertiary butylphenol and 45 g of hydrazine hydrate in 380 ml of pyridine is refluxed for 5 hours. After the pyridine is distilled off under reduced pressure, to the obtained residue is added water. The crude crystals precipitated are recrystallized from ethanol to give 62.5 g of 3-(3,5-di-tertiary butyl-4-hydroxyphenyl)-1H-pyrazolo[3,4-b]pyridine as white crystals, melting at 216°-217° C.

1. distillationAfter the pyridine is distilled off under reduced pressure, to the obtained residue
2. additionis added water
3. customThe crude crystals precipitated
4. customare recrystallized from ethanol