反应详情

A solution of hydrazine hydrate (459 mg, 9.16 mol) in ethanol (5 mL) was added to a solution of ethyl 3-ethoxy-2-(trifluoroacetyl)acrylate (2.00 g, 8.33 mmol) in ethanol (15 mL) at 0° C. The reaction was allowed to warm to RT and stirred for 24 hrs. The reaction was concentrated in vacuo, dissolved in ethyl acetate (30 mL), washed with 5% citric acid (25 mL), saturated sodium bicarbonate (25 mL) and brine (25 mL), dried (Na2SO4) and concentrated in vacuo to afford ethyl 3-(trifluoromethyl)-1H-pyrazole-4-carboxylate (1.365 g, 79% yield). 1H NMR (300 MHz, DMSO-d6): δ 1.24 (t, 3 H), 4.22 (q, 2 H), 8.56 (s, 1 H); MS (ESI) m/z: 209.0 (M+H+).

1. concentrationThe reaction was concentrated in vacuo
2. dissolutiondissolved in ethyl acetate (30 mL)
3. washwashed with 5% citric acid (25 mL), saturated sodium bicarbonate (25 mL) and brine (25 mL)
4. dry with materialdried (Na2SO4)
5. concentrationconcentrated in vacuo