Dimethyl hydrazine-1,2-dicarboxylate–triphenylphosphine oxide (1/1)

In the crystal structure of the title compound, C4H8N2O4·C18H15OP, two triphenylphosphine oxide molecules and two dimethyl hydrazine-1,2-dicarboxylate molecules are connected via N—H...O hydrogen bonds of moderate strength and are related via a twofold rotational axis. Weak Car—H... O contacts strengthen the crystal structure.