Altox

Database / Pharmaceutical impurity

Pharmaceutical impurity

Phenytoin EP Impurity D

Phenytoin EP Impurity D is listed in the pharmaceutical impurity collection under CAS 5157-15-3. Its represented structure has formula C16H14N4O2 and a calculated molecular weight of 294.31 g/mol.

2D chemical structure

O N H N H O H N H N

Chemical identity

Catalog name
Phenytoin EP Impurity D
Common name
Phenytoin EP Impurity D
Chemical name
3a,6a-diphenyl-1,3,4,6-tetrahydroimidazo[4,5-d]imidazole-2,5-dione
CAS
5157-15-3
SMILES
O=C1NC2(c3ccccc3)NC(=O)NC2(c2ccccc2)N1
InChI
InChI=1S/C16H14N4O2/c21-13-17-15(11-7-3-1-4-8-11)16(19-13,20-14(22)18-15)12-9-5-2-6-10-12/h1-10H,(H2,17,19,21)(H2,18,20,22)
InChIKey
WUDVGTHXCLJVJN-UHFFFAOYSA-N
Associated API
Phenytoin

Record ID: A111a0ef54341

Computed properties

C16H14N4O2 Molecular formula
294.314 g/molMolecular weight
294.1117 DaMonoisotopic exact mass
82.26 ŲTopological polar surface area
1.318 Calculated LogP (Wildman–Crippen)
79.5748 cm³/molMolar refractivity (Wildman–Crippen)
2 countHydrogen-bond acceptors
4 countHydrogen-bond donors

Descriptors are calculated from the displayed SMILES. Calculated LogP is not a measured partition coefficient or a pH-specific LogD.

Molecular descriptor profile

Descriptor radar

Mol. weight LogP TPSA HBA HBD Rotatable 25 50 75 100

Structural feature counts

0 2 4 Count H-bond acceptors H-bond donors Rotatable bonds Rings Aromatic rings Stereo centers

Element composition

C H N O 0 4 8 12 16 Number of atoms

Radar scale: 0–100 percentile within 25,771 distinct represented structures in this release, using the midpoint rank for ties. Larger values indicate a higher descriptor rank, not greater safety or toxicity. Element counts include hydrogen and combine isotopes under each element.

Radar values and percentile reference
DescriptorValuePercentile
Molecular weight294.31442.37
Calculated LogP (Wildman–Crippen)1.31830.40
Topological polar surface area82.2659.79
Hydrogen-bond acceptors215.92
Hydrogen-bond donors489.70
Rotatable bonds (strict)224.16

Complete molecular descriptors

PropertyCalculated valueUnit / type
Molecular formulaC16H14N4O2dimensionless
Molecular weight294.314g/mol
Monoisotopic exact mass294.1117Da
Topological polar surface area82.26Ų
Calculated LogP (Wildman–Crippen)1.318dimensionless
Molar refractivity (Wildman–Crippen)79.5748cm³/mol
Hydrogen-bond acceptors2count
Hydrogen-bond donors4count
Rotatable bonds (strict)2count
Heavy atoms22count
Heteroatoms6count
Rings4count
Aromatic rings2count
Aliphatic rings2count
Saturated rings2count
Aromatic heterocycles0count
Aliphatic heterocycles2count
Saturated heterocycles2count
Aromatic carbocycles2count
Aliphatic carbocycles0count
Fraction of sp³ carbon atoms0.125fraction
Formal charge0e
Disconnected components1count
Isotopically specified atoms0count
Potential atom stereocenters0count
Unspecified atom stereocenters0count
Spiro atoms0count
Bridgehead atoms0count
Labute approximate surface area126.4591Ų
Valence electrons110count
Radical electrons0count
Bertz complexity663.7558index
Balaban J1.9753index

Ring categories overlap and should not be summed. No toxicity result, PDE, HBEL or acceptable intake is inferred from these descriptors.

Toxicological services and resources for Phenytoin EP Impurity D

Qualification and safety assessment of Phenytoin EP Impurity D

Explore toxicological qualification of Phenytoin EP Impurity D and ICH M7 mutagenic impurity assessment of Phenytoin EP Impurity D for evaluation of this impurity in its pharmaceutical context.

Where data gaps need to be addressed, resources include read-across assessment for Phenytoin EP Impurity D and acceptable intake and limit justification for Phenytoin EP Impurity D. The relevant approach depends on the available evidence, exposure and duration of use.

Related Altox services and technical resources

Other catalogue designations with the same represented structure

These are separate catalogue entries; shared structure does not establish interchangeable pharmacopoeial designations.

Identity sources and calculation method

Identifiers originate from the source catalogues and available public identity records. InChI and InChIKey on this page are generated from the displayed SMILES. RDKit validation checks the molecular representation; it does not independently verify every catalogue assignment.

Discuss an assessment for Phenytoin EP Impurity D

Explore Altox services and software through the Altox Pharma-Hub.