An efficient one-pot method is described for the highly regioselective synthesis of α-ketoamide -arylpyrazoles from secondary β-enamino diketones. For this, the key intermediate, 4-acyl 3,5-dihydroxypyrrolone, was generated in situ and underwent bimolecular nucleophilic substitution at C-5 by arylhydrazine, with subsequent heterocyclization at the carbonyl carbon of the acyl group. This strategy allowed for regiochemical control of α-ketoamide -arylpyrazoles from β-enamino diketones and arylhydrazines.
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