反应详情

3-Ethoxycarbonyl-7-hydroxypyrazolo[1,5-a]pyrimidine-6-carboxylic acid (27.0 g, 0.11 mol) obtained in Example 19, step 2 was suspended in 1,2-dichloroethane (320 mL), and thionyl chloride (39 mL, 0.54 mol) was added. DMF (22 mL) was added, and the mixture was heated under reflux for 6 hr. The reaction mixture was cooled to room temperature, and the solvent was evaporated under reduced pressure. The residue was suspended in methylene chloride (300 mL), and triethylamine (75 mL, 0.54 mol) was added in an ice bath. Methanol (50 mL) was added dropwise over 30 min, and the mixture was stirred at room temperature for 2 hr. The solvent was evaporated under reduced pressure, and the residue was added to 2 mol/L hydrochloric acid containing ice (about 500 mL). The precipitated solid was collected by filtration, and washed with water (50 mL) to give the title compound (27.5 g, 95%).

1. temperaturethe mixture was heated
2. temperatureunder reflux for 6 hr
3. customthe solvent was evaporated under reduced pressure
4. customThe solvent was evaporated under reduced pressure
5. additionthe residue was added to 2 mol/L hydrochloric acid
6. additioncontaining ice (about 500 mL)
7. filtrationThe precipitated solid was collected by filtration
8. washwashed with water (50 mL)