反应详情

3-Aminopyrazole (9 g, 108 mmol) was dissolved in DCM (250 ml). Triethylamine (27 g, 262 mmol) was added in one portion. Pivaloyl chloride (30 g, 248 mmol) was added slowly at room temperature. After stirring at room temperature for 6 hours, the solvent was concentrated under reduced pressure to give a solid. The solid was dissolved in methanol (200 ml). Aqueous NaOH (2.5M, 120 ml) was added slowly and the mixture was stirred at room temperature for 30 minutes. The solvent was evaporated off under reduced pressure. The slurry was transferred into water (300 ml). The solid was filtrated and dried to give the title product (13.5 g) as a yellow solid, yield: 76%. 1H-NMR (400 MHz, d6-DMSO): δ 12.3 (s, 1H), 9.77 (s, 1H), 7.58 (s, 1H), 6.49 (s, 1H), 1.2 (s, 9H).

1. concentrationthe solvent was concentrated under reduced pressure
2. customto give a solid
3. stirringthe mixture was stirred at room temperature for 30 minutes
4. customThe solvent was evaporated off under reduced pressure
5. filtrationThe solid was filtrated
6. customdried