Phenidone

Phenidone
Names
Preferred IUPAC name
1-Phenylpyrazolidin-3-one
Identifiers
3D model (JSmol)
ChEMBL
ChemSpider
ECHA InfoCard 100.001.960 Edit this at Wikidata
EC Number
  • 202-155-1
UNII
  • InChI=1S/C9H10N2O/c12-9-6-7-11(10-9)8-4-2-1-3-5-8/h1-5H,6-7H2,(H,10,12) checkY
    Key: CMCWWLVWPDLCRM-UHFFFAOYSA-N checkY
  • InChI=1/C9H10N2O/c12-9-6-7-11(10-9)8-4-2-1-3-5-8/h1-5H,6-7H2,(H,10,12)
    Key: CMCWWLVWPDLCRM-UHFFFAOYAF
  • O=C2NN(c1ccccc1)CC2
Properties
C9H10N2O
Molar mass 162.192 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
Occupational safety and health (OHS/OSH):
Main hazards
 Harmful if swallowed
GHS labelling:
GHS07: Exclamation markGHS09: Environmental hazard
Warning
H302, H411
P264, P270, P273, P301+P312, P330, P391, P501
Safety data sheet (SDS) External MSDS
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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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, capable of achieving the same level of development in both less time and at a lower concentration.[1] It also has low toxicity and unlike some other developers, does not cause dermatitis upon skin contact.[2] As a developer, Phenidone is typically used in conjunction with hydroquinone for black and white photography and performs better at lower pH levels.[3]

Phenidone is Ilford's trademark for this material, which was first filed on Feb. 24, 1953, but has since expired.[4] Although the compound 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.[5]

Phenidone functions as a reducing agent. It converts to the N-phenyl-hydroxypyrazole. It is oxidized in acidic conditions, contributing the electrons it loses to reduce silver halides such as those found in film[6]:

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

Phenidone is also a dual cyclooxygenase/lipoxygenase inhibitor, capable of blocking the synthesis ofarachidonic acid, which plays a role in causing inflammation in systemic inflammatory response syndrome[7] and neuronal damage in kainic acid-induced seizures.[8]

  1. ^ Axford, A.J.; Kendall, J.D. (January 1, 1954). "Phenidone—Part 1; The Mechanism of its Developing Action and its Super-additivity with Hydroquinone *". The Journal of Photographic Science. 2 (1): 1–7. doi:10.1080/03700240.1954.11736538. ISSN 0370-0240.
  2. ^ Merck Index of Chemicals and Drugs, 9th ed. monograph 7115
  3. ^ Mason, L. F. A. (January 1, 1965). "Role of Phenidone in Modern Processing". The Journal of Photographic Science. 13 (4): 205–209. doi:10.1080/00223638.1965.11737306. ISSN 0022-3638.
  4. ^ "Trademark Status & Document Retrieval". tsdr.uspto.gov. Retrieved 2024-11-19.
  5. ^ Karlheinz Keller et al. "Photography" in Ullmann's Encyclopedia of Industrial Chemistry, 2005, Wiley-VCH, Weinheim. doi:10.1002/14356007.a20_001
  6. ^ Spirin, M. G.; Brichkin, S. B.; Razumov, V. F. (2002). "Phenidone Oxidation during Photoinitiated Chemical Reduction of AgBr Nanocrystals in Water Pools of Reverse Micelles". Colloid Journal. 64 (3): 364–368. doi:10.1023/A:1015981028758.
  7. ^ Schroeder, Torsten (March 2008). "Activity of the lipoxygenase inhibitor 1-phenyl-3-pyrazolidinone (phenidone) and derivatives on the inhibition of adhesion molecule expression on human umbilical vascular endothelial cells". Biologics: Targets & Therapy: 151. doi:10.2147/BTT.S2542. ISSN 1177-5475. PMC 2727783. PMID 19707438.
  8. ^ Kim, Hyoung-Chun; Jhoo, Wang-Kee; Bing, Guoying; Shin, Eun-Joo; Wie, Myung-Bok; Kim, Won-Ki; Ko, Kwang Ho (August 18, 2000). "Phenidone prevents kainate-induced neurotoxicity via antioxidant mechanisms". Brain Research. 874 (1): 15–23. doi:10.1016/S0006-8993(00)02560-9.