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IUPAC name
Other names
C.I. 10355
Molar mass 169.23 g/mol
Appearance White colorless solid
Odor Dry plant-like
Density 1.16 g/cm3
Melting point 53 °C (127 °F; 326 K)
Boiling point 302 °C (576 °F; 575 K)
0.003 g/100 ml (0 °C)
0.00316 g/100 ml (15 °C)
0.007 g/100 ml (28 °C)
0.012 g/100 ml (50 °C)
0.032 g/100 ml (85 °C)[1]
Solubility Reacts with acids
Soluble in acetone, benzene, carbon disulfide, carbon tetrachloride, diethyl ether, ethanol, ethyl acetate, methanol, pyridine, xylene
Solubility in acetone 239.83 g/100 ml (0 °C)
298.59 g/100 ml (28 °C)
Solubility in benzene 110.674 g/100 ml (0 °C)
277.99 g/100 ml (28 °C)
Solubility in carbon disulfide 112.452 g/100 ml (0 °C)
314.12 g/100 ml (28 °C)
Solubility in carbon tetrachloride 27.734 g/100 ml (0 °C)
122.63 g/100 ml (28 °C)
Solubility in chloroform 86.545 g/100 ml (0 °C)
206.26 g/100 ml (28 °C)
Vapor pressure 6.7·10-4 mmHg (25 °C)
142.5 kJ/mol
Safety data sheet Sigma-Aldrich
Flash point 152 °C (306 °F; 425 K)
Lethal dose or concentration (LD, LC):
2,900 mg/kg (mouse, oral)
Related compounds
Related compounds
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Diphenylamine is an organic compound with the formula (C6H5)2NH. The compound is a derivative of aniline, consisting of an amine bound to two phenyl groups.



Diphenylamine is a weak base, with a Kb of 10−14. It reacts with acids to form salts.

Diphenylamine undergoes various cyclisation reactions. With sulfur, it gives phenothiazine, a precursor to pharmaceuticals.[2]

(C6H5)2NH + 2 S → S(C6H4)2NH + H2S

With iodine, it undergoes dehydrogenation to give carbazole, with release of hydrogen iodide:

(C6H5)2NH + I2 → (C6H4)2NH + 2 HI

Arylation with iodobenzene gives triphenylamine.[3]

Oxidation of diphenylamine with potassium permanganate yields tetraphenylhydrazine.

Diphenylamine slowly oxidizes in air, turning gray, yellow, orange or brown.


Diphenylamine is a colorless solid, insoluble in water but very soluble in organic solvents. Impure product tends to be gray or brown.


Diphenylamine is sold by chemical suppliers.


Diphenylamine is manufactured by the thermal deamination of aniline over oxide catalysts:

2 C6H5NH2 → (C6H5)2NH + NH3

Can also be prepared by reacting acetanilidie with bromobenzene. The reaction yields N,N-diphenylacetamide, which is hydrolyzed with HCl to crude diphenylamine hydrochloride, which is then purified to diphenylamine.[4]


  • Make triphenylamine
  • Stabilizer for reagents and energetic materials, such as smokeless powder
  • Redox indicator in alkaline redox titrations
  • Diphenylamine test for nitrates
  • Synthesis of azo dyes (Metanil Yellow, Disperse Orange 1, Acid orange 5, etc.)
  • Synthesis of tetraphenylhydrazine
  • Apple scald inhibitor



Diphenylamine appears to be moderate toxic. It can cause severe irritation to the eyes, though it is not a skin irritant. Diphenylamine targets the red blood cell system and can cause abnormal erythropoiesis in the spleen, and thus congestion of the spleen, and haemosiderosis. Changes in liver and kidneys were found upon longer exposure.

Diphenylamine has low acute and short-term toxicity to birds, but is very toxic to aquatic organisms. Risk to biological methods of sewage treatment was assessed as low.


In closed airtight bottles, away from acids and air.


Can be neutralized by burning it in an incinerator.


  1. Seidell A. Solubilities of organic compounds. - 3ed., vol.2. - New York: D. Van Nostrand Company, 1941
  2. https://onlinelibrary.wiley.com/doi/10.1002/14356007.a02_303 T. Kahl, K.-W. Schröder, F. R. Lawrence, W. J. Marshall, Hartmut Höke, Rudolf Jäckh, "Aniline" in Ullmann's Encyclopedia of Industrial Chemistry, 2005, Wiley-VCH: Weinheim
  3. http://www.orgsyn.org/demo.aspx?prep=CV1P0544
  4. https://www.prepchem.com/synthesis-of-diphenylamine/

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