反应详情

温度

120 °C

96 gms. of benzoylacetic acid ethyl ester (0.5 mol.) are added dropwise to a stirred mixture of 55.5 gms. of 5-amino-1,3-dimethylpyrazole (0.5 mol) and 250 gms. of polyphosphorus acid heated to 120° C. After the reaction has occurred, which can be recognized by the changing of the color, the whole is heated for an additional hour at 120° C. After the mixture has cooled to room temperature, 600 ml. of water are added and stirring is continued until the compound becomes crystalline. The mixture is allowed to stand overnight and is then filtered off. The collected 1,3-dimethyl-4-hydroxy-6-phenyl-1H-pyrazolo[3,4-b]pyridine is washed with dilute ammonia, dried and treated with ethyl acetate yielding 73.6 gms. (61.6%), m.p. 262°-264°.

1. temperaturethe whole is heated for an additional hour at 120° C
2. temperatureAfter the mixture has cooled to room temperature
3. filtrationis then filtered off
4. washThe collected 1,3-dimethyl-4-hydroxy-6-phenyl-1H-pyrazolo[3,4-b]pyridine is washed with dilute ammonia
5. customdried
6. additiontreated with ethyl acetate yielding 73.6 gms