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 (MAI).

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-540c809f128b42a892aa9fe13765a847

Source dataset

uspto-grants-2013_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08519129B2