Rh(III)-catalyzed intermolecular C-H amination of 1-aryl-1H-pyrazol-5(4H)-ones with alkylamines.

An intermolecular C-H amination of 1-aryl-1H-pyrazol-5(4H)-ones was achieved under mild reaction conditions, using a low catalyst loading and with a broad scope of aminating reagents. This protocol not only provides the first example of rhodium(III)-catalyzed intermolecular aromatic C-H amination directed by an intrinsic functionality of the substrate/product but also features aminating an existing drug with either primary or secondary N-benzoate alkylamines as the coupling partners.