 They are commonly used in combination with azo groups to give a sub-family of azo dyes; sometimes referred to as azopyrazolones (tartrazine, orange B, mordant red 19, yellow 2G).Acid Yellow 17, Acid Yellow 23 (tartrazine), Pigment Yellow 13, and Pigment Red 38 are produced on the multi-ton scale annually.Pyrazolones have been studied as ligands.