Compound: Phenidone
SMILES: O=C1NN(c2ccccc2)CC1
InChIKey: CMCWWLVWPDLCRM-UHFFFAOYSA-N
Synonyms: Phenidone, 92-43-3, 1-PHENYL-3-PYRAZOLIDINONE, 1-Phenyl-3-pyrazolidone, 3-Pyrazolidinone, 1-phenyl-, DTXSID1049433, H0U5612P6K, NSC-30306, DTXCID0029393, RefChem:172692, 202-155-1, 1-phenylpyrazolidin-3-one, Fenidon, Pyrazolidinone, 1-phenyl-, 1-Phenyl-3-oxopyrazolidine, 2-Pyrazolin-3-ol, 1-phenyl-, MFCD00003094, 1-P-3-P, 1-Phenyl-pyrazolidin-3-one, 1-Phenylpyrazolid-3-one, CHEMBL7660, 1-phenyl-4,5-dihydro-1H-pyrazol-3-ol, MLS002639322, Phenidone A, CCRIS 3624, EINECS 202-155-1, UNII-H0U5612P6K, Edaravone Impurity 25, WLN: T5NMVTJ AR, N-phenylpyrazolidin-3-one, ChemDiv3_006595, TimTec1_001225, Oprea1_428400, SCHEMBL235192, orb1305951, SCHEMBL7549726, SCHEMBL7549730, SCHEMBL9670254, SCHEMBL14916963, 2-Pyrazolin-3-one, 1-phenyl-, 1-Phenyl-3-pyrazolidinone, 97%, HMS1491L17, HMS1537H15, HMS3091P11, HMS3886E10, ALBB-010492, NSC30306, Tox21_202877, BDBM50009004, EBC-00002, s5520, SBB000141, STK084358, STK741678, AKOS000119161, AKOS003264132, pyrazole, tetrahydro-3-oxo-1-phenyl-, (phenidone)1-Phenyl-pyrazolidin-3-one, 1-Phenyl-pyrazolidin-3-one(Phenidone), CCG-207926, CS-W010860, FS-4504, HY-W010144, SDCCGMLS-0064787.P001, CAS-92-43-3, IDI1_024505, 1-PHENYL-3-PYRAZOLIDINONE [MI], 1-Phenyl-pyrazolidin-3-one (Phenidone), NCGC00174656-01, NCGC00260423-01, SMR001548767, ST016346, SY048400, DB-057302, NS00019857, P0153, EN300-19052, D78316, F368147, SR-01000516084, Q3297749, SR-01000516084-1, F0905-7615, Z104472448, 14776-33-1, InChI=1/C9H10N2O/c12-9-6-7-11(10-9)8-4-2-1-3-5-8/h1-5H,6-7H2,(H,10,12
Theoretical properties:
molecular_formula: C9H10N2O
molecular_weight: 162.19 g/mol
exact_mass: 162.079312947 g/mol
formal_charge: 0
hydrogen_bond_donor_count: 1
hydrogen_bond_acceptor_count: 2
rotatable_bond_count: 1
heavy_atom_count: 12
topological_polar_surface_area: 32.3 Å²
isotope_atom_count: 0
covalently_bonded_unit_count: 1
Physical properties:
vapor_pressure: 0.0000163 [mmHg]
Descriptions:
chembl: PHENIDONE is a small molecule listed in the ChEMBL database but has not progressed to an approved clinical phase.
wikipedia: Phenidone (1-phenyl-3-pyrazolidinone) is an organic compound that is primarily used as a photographic developer. It has ten to eighteen times the amount of efficiency and stability as Metol, capable of achieving the same level of development in both less time and at a lower concentration. It also has low toxicity and unlike some other developers, does not cause dermatitis upon skin contact. As a developer, Phenidone is typically used in conjunction with hydroquinone for black and white photography and performs better at lower pH levels (about 9.8-10.4). This is comparable to Metol whose working pH is approximately 10.3. 
Phenidone is Ilford's trademark for this material, which was first filed on Feb. 24, 1953, but has since expired. 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. It begun to be used by large companies, such as Agfa/Orwo, in the 1960s in place of Metol. 
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:

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