Iodine → 3,5-diethyl 4-iodo-1H-pyrazole-3,5-dicarboxylate

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Reaction Steps

To a solution of 10 g 1H-Pyrazole-3,5-dicarboxylic acid diethyl ester in 400 ml acetonitrile 13 g ammonium cerium(iv) nitrate (CAN) and 7.17 g iodine were added and the mixture was heated to reflux for 5 h. Then, after cooling to RT, 30 ml sat. sodium thiosulfate solution were added. The mixture was extracted with ethyl acetate (3×100 ml), the combined organic layers were washed with water and then dried over MgSO4, filtered and the solvents were removed under reduced pressure. The residue was filtered through a pad of silica gel eluting with heptane/ethyl acetate 1:1. Yield: 13 g.

Provenance & Evidence