Hydrazine → 3-(trifluoromethyl)-1H-pyrazol-5-amine

Temperature

80 °C

A mixture of (E)-4-amino-4-ethoxy-1,1,1-trifluorobut-3-en-2-one (5.00 g, 27 mmol) and hydrazine (1.05 g) in anhydrous EtOH (20 mL) was stirred at 80° C. in a sealed vial overnight. The reaction was quenched with water (50 mL), and extracted with EtOAc (100 ml, then 2×50 mL). The EtOAc layers were combined and sequentially washed with water (25 mL), brine (25 mL), dried over Na2SO4 and evaporated to give a light brown oily residue. The crude product was purified by silica chromatography (30-100% EtOAc in hexanes gradient) to give 5-(trifluoromethyl)-1H-pyrazol-3-amine as an off white solid; ESMS m/z 152.0 (M+H+).

1. customThe reaction was quenched with water (50 mL)
2. extractionextracted with EtOAc (100 ml
3. washsequentially washed with water (25 mL), brine (25 mL)
4. dry with materialdried over Na2SO4
5. customevaporated
6. customto give a light brown oily residue
7. customThe crude product was purified by silica chromatography (30-100% EtOAc in hexanes gradient)

ORD record

ord-3a987e84a18b4d508bbce2aee4d78131

Source dataset

uspto-grants-2014_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08859574B2