1,2-Diazenedicarboxylic Acid 1-Ethyl 2-(phenylmethyl) Ester is an intermediate used to synthesize Tetrahydro-1H-pyrazolo[1,2-a]pyridazine-1,3(2H)-dione (T296020) which is a reagent used to prepare alkylphenylpyrazolines, -pyrroles, -furans, -thiophenes, or -thiazines as herbicides.