phenylenediamine

noun

phe·​nyl·​ene·​di·​amine ˈfen-ᵊl-ˌēn-ˈdī-ə-ˌmēn, ˈfēn- 

: any of three toxic isomeric crystalline compounds C₆H₈N₂ that are derivatives of benzene containing two amino groups attached to carbon atoms in the ortho, meta, or para positions see quinoxaline