反应详情

温度

75 °C

A mixture of 3-amino-5-methylpyrazole (50.0 g), pyruvic acid methyl ester (58.4 g) and 4-hydroxybenzaldehyde (62.9 mL) in acetic acid/methanol (v/v=1/1, 300 mL) was stirred at 75° C. for 15 h, cooled to r.t., and the precipitate formed was isolated by suction filtration and dried in vacuum at 60° C. 6-(4-Hydroxy-phenyl)-3-methyl-1H-pyrazolo[3,4-b]pyridine-4-carboxylic acid methyl ester (15 g, 10% yield) were obtained as pale yellow solid.

1. temperaturecooled to r.t.
2. customthe precipitate formed
3. customwas isolated by suction filtration
4. customdried in vacuum at 60° C