Phenidone

Phenidone
Names
IUPAC name
1-phenyl-3-pyrazolidinone
Identifiers
92-43-3 Yes
ChEMBL ChEMBL7660 Yes
ChemSpider 6823 Yes
EC number 202-155-1
Jmol-3D images Image
PubChem 7090
Properties
Molecular formula
C9H10N2O
Molar mass 162.19 g·mol−1
Appearance Crystal leaflets or needles
Melting point 121 °C (250 °F; 394 K)
10 g/100 ml at 100 °C
Solubility in ethanol 10 g/100 ml (hot)
Solubility in diethyl ether practically insoluble
Hazards
MSDS External MSDS
Main hazards Harmful if swallowed
R-phrases R20 R22
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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Infobox references

Phenidone (1-phenyl-3-pyrazolidinone) is an organic compound that is primarily used as a photographic developer. It has five to ten times the developing power as Metol. It also has low toxicity and, unlike some other developers, does not cause dermatitis upon skin contact.[1]

Phenidone is Ilford's trademark for this material, which was first prepared in 1890. It was not until 1940 that J. D. Kendall, in the laboratories of Ilford Limited, discovered the reducing properties of this compound. Large scale production did not become feasible until 1951.[2]

Phenidone functions as a reducing agent. It converts to the N-phenyl-hydroxypyrazole:

Reaction of phenidone with silver bromide, as occurs in photographic development.

Preparation

Phenidone can be prepared by heating phenyl hydrazine with 3-chloropropanoic acid.[1]

References

  1. 1.0 1.1 Merck Index of Chemicals and Drugs, 9th ed. monograph 7115
  2. Karlheinz Keller et al. "Photography" in Ullmann's Encyclopedia of Industrial Chemistry, 2005, Wiley-VCH, Weinheim. doi: 10.1002/14356007.a20_001