反应详情

A mixture of 2-(5-amino-1-methyl-1 H-pyrazol-3-yl)-2-methylpropanenitrile (1.4 g, 8.5 mmol) in EtOH (30 mL) was treated with cone. H2SO4 (3 mL) and the resulting mixture was refluxed for 10 days. The reaction mixture was neutralized with saturated aq NaHCO3 solution, and the mixture was extracted with EtOAc. The organics were washed with brine, dried (MgSO4) and concentrated in vacuo. Recrystallization (EtOAc/petroleum ether) provided ethyl 2-(5-amino-1-methyl-1 H-pyrazol-3-yl)-2-methylpropanoate (0.8 g, 44% yield). 1H NMR (300 MHz, DMSO-d6): δ5.13 (s, 1 H), 5.04 (s, 2 H), 4.00 (q, J=6.9 Hz, 2 H), 3.41 (s, 3 H), 1.11 (t, J=6.9 Hz, 6 H); MS (ESI) m/z: 212.0 [M+H]+.

1. additionwas treated with cone
2. extractionthe mixture was extracted with EtOAc
3. washThe organics were washed with brine
4. dry with materialdried (MgSO4)
5. concentrationconcentrated in vacuo
6. customRecrystallization (EtOAc/petroleum ether)