How to Make Phenylenediamine?

The first method involves reacting chlorobenzene with nitric acid and reacting the resulting product, p-nitrochlorobenzene with ammonia to yield 4-nitroaniline, followed by hydrogenation of 4-nitroaniline to produce p-phenylenediamine.

How is phenylenediamine made?

PPD is produced via three routes. Most commonly, 4-nitrochlorobenzene is treated with ammonia and the resulting 4-nitroaniline is then hydrogenated: ClC₆H₄NO₂ + 2 NH₃ → H₂NC₆H₄NO₂ + NH₄Cl. H₂NC₆H₄NO₂ + 3 H₂ → H₂NC₆H₄NH₂ + 2 H₂O.

Where does p-phenylenediamine come from?

P-phenylenediamine, PPD, is one of many coal-tar colors, which are derived from petroleum. Unlike most color additives, coal-tar dyes are exempt from needing FDA approval, despite the numerous health effects associated with coal-tar dyes.