Ethanol → 3-tert-butyl-1-(3-phenoxyphenyl)-1H-pyrazol-5-amine

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

In a 250 mL Erlenmeyer flask with a magnetic stir bar, 3-phenoxyphenylamine (4.81 g, 0.026 mol) was added to 6 N HCl (40 mL) and cooled with an ice bath to 0° C. A solution of NaNO2 (2.11 g, 0.0306 mol, 1.18 eq.) in water (5 mL) was added drop wise. After 30 min, SnCl22H2O (52.0 g, 0.23 mol, 8.86 eq.) in 6 N HCl (100 mL) was added and the reaction mixture was allowed to stir for 3 h, and then subsequently transferred to a 500 mL round bottom flask. To this, 4,4-dimethyl-3-oxopentanenitrile (3.25 g, 0.026 mol) and EtOH (100 ml) were added and the mixture refluxed for 4 h, concentrated in vacuo and the residue extracted with EtOAc (2×100 mL) and purified by column chromatography using hexane/EtOAc/Et3N (8:2:0.2) to yield 3-tert-butyl-1-(3-phenoxyphenyl)-1H-pyrazol-5-amine (1.40 g, 17%). mp: 108-110° C.; 1H NMR (CDCl3): δ 7.3 (m, 10H), 5.7 (s, 1H), 4.9 (brs, 2H), 1.3 (s, 9H).

Herkunft & Nachweise