Water → ethyl 4-chloro-5-methyl-1H-pyrazole-3-carboxylate

Beteiligte Stoffe

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Reaktionsschritte

To a solution of ethyl 5-methyl-1H-pyrazole-3-carboxylate (Maybridge, 4.41 g, 28.6 mmol) in DMF (14 mL) was added N-chlorosuccinimide (3.86 g, 28.9 mmol). The resulting solution was heated at 60° C. for 3 h and then cooled to room temperature. Water was added until a white precipitate formed, and the solid was collected by filtration washing with water. The solid was dissolved in CH2Cl2, washed with water (2×), dried over MgSO4 and concentrated in vacuo to provide the title compound (5.14 g, 90%) as a white solid. 1H NMR (CDCl3) δ 8.03 (s, 1H), 4.42 (q, J=7.0 Hz, 2H), 2.32 (s, 3H), 1.42 (t, J=7.1 Hz, 3H); MS(ESI+) m/z 188.9 (M+H)+.

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