Reaktion #340405

Reaktionsgleichung

α-acetylacetonitrile

triethylamine

hydrazine dihydrochloride

→

3-methyl-4-phenyl-1H-pyrazol-5-amine

Ausbeute 176.2%

Lösungsmittel

ethanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturbefore cooling to rt
2. 2
   SonstigeThe volatile materials were removed in vacuo
3. 3
   SonstigeThe crude residue was purified by flash chromatography (gradient: 5% methanol in CH2Cl2 to 10% methanol in CH2Cl2)

Vorschrift

To a solution of α-acetylacetonitrile (2 g, 12.6 mmol) in ethanol was added triethylamine (1.05 mL, 7.6 mmol) and hydrazine dihydrochloride (1.6 g, 15.1 mmol). The mixture was heated to 80° C. and stirred for 2 h before cooling to rt. The volatile materials were removed in vacuo. The crude residue was purified by flash chromatography (gradient: 5% methanol in CH2Cl2 to 10% methanol in CH2Cl2) to provide 1.92 g of 3-methyl-4-phenyl-1H-pyrazol-5-amine (11.1 mmol, 88% yield). 1H NMR (400 MHz, CDCl3): δ7.40 (m, 2H), 7.34-7.32 (m, 2H), 7.27-7.23 (m, 1H), 3.71 (br s, 2H), 2.30 (s, 3H); MS (EI) for C10H11N3: 174 (MH+).

Quelle