Nitrodeiodination of Polyiodopyrazoles: a Convenient Synthesis of 4-Nitroiodopyrazoles

A number of 3,4-, 4,5-diiodo- and 3,4,5-triiodo-1-methylpyrazoles 2a–f have been converted into the corresponding almost inaccessible 3-, 5-iodo- and 3,5-diiodo-1-methyl-4-nitropyrazoles 3a–f by nitration with an HNO₃–H₂SO₄ mixture.