Triethylamine → Ethyl 1-(6-chloropyridin-2-yl)-5-(trifluoromethyl)-1h-pyrazole-4-carboxylate

Participants

Reaction Steps

To a solution 2-chloro-6-hydrazinopyridine (1.00 g, 6.97 mmol) and triethylamine (971 mL, 6.97 mmol) in acetonitrile (35 mL) was added ethyl 2-(ethoxymethylene)-4,4,4-trifluoro-3-oxobutyrate (1.36 mL, 6.97 mmol). After 20 min, the reaction mixture was placed in a 60° C. oil bath. After 30 min, the reaction mixture was allowed to cool to ambient temperature, then was concentrated in vacuo. Purification by flash chromatography on silica gel (0 to 30% EtOAc in hexanes, then 30 to 100% EtOAc in hexanes) gave the title compound (PCT publication WO 2009/032249): LCMS m/z 319.9 [M+H]; 1H NMR (500 MHz, CDCl3) δ 8.10 (s, 1 H),7.88 (t, J=7.5 Hz, 1 H),7.58 (d, J=8.0 Hz, 1 H),7.47 (d, J=8.0 Hz, 1 H),4.38 (q, J=7.0 Hz, 2 H), 1.38 (t, J=7.0 Hz, 3 H).

Provenance & Evidence