反应详情

温度

95 °C

4-Bromo-1H-pyrazole-3-carbonitrile (150 mg, 0.87 mmol) is dissolved in 3,4-dihydro-2H-pyran (25 mL, 2.6 mmol) in the presence of a catalytic amount of TFA (1 mg, 0.009 mmol). The reaction mixture is stirred at 95° C. for 1 hour, cooled and then quenched using NaH (1.2 mg, 0.052 mmol). After removing the solvent, the residue is purified by silica gel column chromatography eluting with a mixture of 3:1 petroleum ether-dichloromethane, followed by 10:1 petroleum ether-ethyl acetate. The fractions containing the desired compounds are collected and concentrated in vacuo to afford the title compound as a colorless oil (90 mg, 40%).

1. temperaturecooled
2. customquenched
3. customAfter removing the solvent
4. customthe residue is purified by silica gel column chromatography
5. washeluting with a mixture of 3:1 petroleum ether-dichloromethane
6. additionThe fractions containing the desired compounds
7. customare collected
8. concentrationconcentrated in vacuo