Iodine → ethyl 2-(5-acetamido-4-iodo-3-phenyl-1H-pyrazol-1-yl)acetate

Participants

Reaction Conditions

Reaction Steps

A suspension of ethyl 2-(5-acetamido-3-phenyl-pyrazol-1-yl)acetate (37 g, 129 mmol), iodic acid (5.6 g, 32 mmol) and iodine (19.7 g, 77 mmol) in ethanol (400 mL) was heated at 50° C. for 2 h and cooled to room temperature. The reaction mixture was concentrated in vacuo and the residue was eluted through a pad of silica gel with CH2Cl2 diethyl ether (1:0 to 97:3). The residue was partitioned between CH2Cl2 and 2 M Na2S2O3 aq. solution. The layers were separated and the organic washed was dried (MgSO4), and concentrated in vacuo to provide a residue that was partially purified by chromatography (silica gel, CH2Cl2/isohexane 1:1 to 1:0, then CH2Cl2/diethyl ether 9:1 to 8:2), then triturated with diethyl ether to provide the title compound as an off-white solid (43 g).

Provenance & Evidence