Diphenylamine

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Diphenylamine
Skeletal formula
Ball-and-stick model
style="background: #F8EABA; text-align: center;" colspan="2" | Identifiers
CAS number 122-39-4 YesY
RTECS number 9
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style="background: #F8EABA; text-align: center;" colspan="2" | Properties
Molecular formula C12H11N
Molar mass 169.23 g/mol
Appearance White crystals
Density 1.2 g/cm³
Melting point

53 °C (326 K)

Boiling point

302 °C (575 K)

Solubility in water Slightly
style="background: #F8EABA; text-align: center;" colspan="2" | Hazards
R-phrases R23 R24 R25 R33 R50 R53
S-phrases S36 S37 S45 S60 S61
NFPA 704
1
3
0
Flash point 152°C
style="background: #F8EABA; text-align: center;" colspan="2" | Related compounds
Related Amine Aniline
 YesY (what is this?)  (verify)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Diphenylamine is the organic compound with the formula (C6H5)2NH. It is a colourless solid, but samples are often yellow due to oxidized impurities.[1]

Preparation and reactivity

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

2 C6H5NH2 → (C6H5)2NH + NH3

It is a weak base, with a Kb of 10−14. With strong acids, it forms the water soluble salt.

Applications

Diphenylamine is used as a pre- or postharvest scald inhibitor for apples. Its anti-scald activity is the result of its antioxidant properties, which protect the apple skin from the oxidation products of alpha-farnesene during storage.[2]

Diphenylamine derivatives are also useful. Ring-alkylated derivatives of diphenylamine are used as "antiozinates" in the manufacture of rubber products, reflecting the antioxidant nature of aniline derivatives. The compound undergoes various cyclisaton reactions. With sulfur, it gives phenothiazine, a precursor to certain pharmaceuticals.[3]

(C6H5)2NH + 2 S → S(C6H4)2NH + H2S

With iodine, it cyclises to carbazole:

(C6H5)2NH + I2 → (C6H4)2NH + 2 HI

Arylation with iodobenzene gives triphenylamine.[4]

Diphenylamine finds niche use as a test for nitrates (see nitrate test).

References

  1. P. F. Vogt, J. J. Gerulis, “Amines, Aromatic” in Ullmann’s Encyclopedia of Industrial Chemistry 2005, Wiley-VCH, Weinheim.
  2. "Apple Scald, a Complex Problem" W.J. Bramlage (University of Massachusetts Department of Plant and Soil Sciences) Post Harvest Pomology Newsletter, 6(2): 11-14 September 1988 http://postharvest.tfrec.wsu.edu/pgDisplay.php?article=N6I2C
  3. 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.
  4. F. D. Hager (1941), "Triphenylamine", Org. Synth. ; Coll. Vol., 1: 544  Missing or empty |title= (help)

External links

fr:Diphénylamine it:Difenilammina nl:Difenylamine ja:ジフェニルアミン pl:Difenyloamina pt:Difenilamina ru:Дифениламин fi:Difenyyliamiini zh:二苯胺