2-Chloroacrylonitrile → 1-tert-Butyl-1H-pyrazol-3-amine

Temperature

80 °C

A mixture of tert-butylhydrazine (2.4 g, 27 mmol), 2-chloroacrylonitrile (2.9 g, 33 mmol), NaOAc (3.17 g, 38 mmol) and ethanol (30 mL) was heated to 80° C. with stirring for 12 h. The solvent was removed in vacuo and the resulting mixture was treated with saturated NaHCO3 solution (200 mL) and extracted with ethyl acetate (200 mL×3). The organic layers were dried over NaSO4, concentrated in vacuo, purified by chromatography (silica gel, 200-300 mesh, petroleum ether:ethyl acetate=2:1 to 1:2) to give 1-tert-butyl-1H-pyrazol-3-amine (1.39 g, 37%) as a brown oil. LC-MS: [M+H]+, 140.2, tR=0.696 min.

1. customThe solvent was removed in vacuo
2. additionthe resulting mixture was treated with saturated NaHCO3 solution (200 mL)
3. extractionextracted with ethyl acetate (200 mL×3)
4. dry with materialThe organic layers were dried over NaSO4
5. concentrationconcentrated in vacuo
6. custompurified by chromatography (silica gel, 200-300 mesh, petroleum ether:ethyl acetate=2:1 to 1:2)

ORD record

ord-5830c03ebfdc46859f6eed8d2db7a0ba

Source dataset

uspto-grants-2015_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09169259B2