Acetic Acid → 4-(Propan-2-yl)-1H-pyrazol-5-amine

Next, 2-formyl-3-methylbutanenitrile 2 (9.97 g, 90 mmol), hydrazine hydrate (5.68 mL, 117 mmol) and glacial acetic acid (9.02 mL, 158 mmol) were dissolved in EtOH (250 mL) and the mixture was heated under reflux for 16 h. The reaction was then concentrated to approximately one third of the original volume. The residue was diluted with sat. NaHCO3 (100 mL) and the product extracted with CH2Cl2 (3×100 mL). The combined organic fractions were washed with brine, dried over MgSO4 and the solvent was removed in vacuum. Crude 4-isopropyl-1H-pyrazol-5-amine (3) was obtained as a yellow oil (7.17 g, 64%).

1. temperaturethe mixture was heated
2. temperatureunder reflux for 16 h
3. concentrationThe reaction was then concentrated to approximately one third of the original volume
4. additionThe residue was diluted with sat. NaHCO3 (100 mL)
5. extractionthe product extracted with CH2Cl2 (3×100 mL)
6. washThe combined organic fractions were washed with brine
7. dry with materialdried over MgSO4
8. customthe solvent was removed in vacuum

ORD record

ord-d940100ff84d48088dd0f14f709bf3f0

Source dataset

uspto-grants-2011_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08067424B2