Palladium-catalyzed amino group arylation of 1,3-disubstituted 1H-pyrazol-5-amine based on Buchwald–Hartwig reaction

An efficient Pd-catalyzed C–N bond formation for the synthesis of different pyrazole derivatives using XPhos as a ligand and KOH as a base is presented. The developed procedure can be successfully applied for the synthesis of 5-N-aryl-1,3-disubstituted 1H-pyrazol-5-amines. Contrary to previously described procedures, this one proceeds in one step utilizing commercially available aminopyrazoles and aryl halides. Thus, a series of 5-N-aryl-1,3-disubstituted 1H-pyrazol-5-amines were obtained with satisfactory yields under optimized reaction conditions.