Introduction of N‐Containing Heterocycles into Pyrazole by Nucleophilic Aromatic Substitution

Abstract The nucleophilic aromatic substitution on 5‐chloropyrazoles activated by the electron‐withdrawing formyl group offers a useful method to introduce a wide range of N‐containing heterocycles into them. The rate of reaction was greatly affected by the electronic nature of the N‐1 substitution.