Chemical identity

Ondansetron

CAS not listed · C18H19N3O

01Identity

Identifiers and names for this exact compound. Empty fields are left unassigned.

Lazychem IDLC-54544
PubChem CID4595
NameOndansetron
CAS RNNot listed
Molecular formulaC18H19N3O
Molecular weight293.4 g/mol
IUPAC name9-methyl-3-[(2-methylimidazol-1-yl)methyl]-2,3-dihydro-1H-carbazol-4-one
InChIKeyFELGMEQIXOGIFQ-UHFFFAOYSA-N

02Structure identifiers

2D structurePubChem CID 4595
Two-dimensional chemical structure of Ondansetron
Two-dimensional structure for the PubChem identity linked to this record. Confirm the identifiers before analytical use.

The parsed structure contains 4 rings, includes aromatic atoms, includes aliphatic carbon. These statements are calculated from the published structure string.

Defined stereocentres0
Unassigned stereocentres1
Ring count4
Secondary amines0
Tertiary amines0
N-methyl amine sites0
SMILESCC1=NC=CN1CC2CCC3=C(C2=O)C4=CC=CC=C4N3C
InChINot listed
Formula from structureC18H19N3O
Molecular weight from structure293.4 g/mol

03Stereochemistry

The published structure contains 0 defined and 1 unassigned tetrahedral stereocentre. The exact wedge and dash depiction is shown above.

Defined centres0Structure assigned
Unassigned centres1Structure unspecified
Assignment statusUnassignedExact published identity
Tetrahedral upper bound≤ 2Before symmetry reduction

Published same-connectivity configurations

1 record

These records have the same connectivity, molecular formula and protonation layer, but a different complete InChIKey stereochemical layer. Only separately structure-linked records are shown.

No additional structure-linked configuration with the same connectivity is currently present in the LazyChem dataset.

Scope: The mathematical 2^n value is only an upper bound. Symmetry and other stereogenic elements can change the number of distinct stereoisomers. A hypothetical configuration is not published as a compound record without a verified structure identity.

04Possible N-nitroso structures

Shown for structural screening only. These candidates are not confirmed impurities, formation predictions or analytical findings.

Matched amine site1 candidate
Chemical structure of Ondansetron with the matched amine site highlighted in amber
Amber identifies the screened atom and adjacent bonds.
Possible structure candidateUnverified identity
First calculated possible N-nitroso structure derived from Ondansetron, with the new N-nitroso group highlighted in amber
The new N-N=O atoms and bonds are highlighted. No CAS number or compound name is assigned by this calculation.
Candidate 1Possible N-nitroso structural candidate
Calculated formula
C17H16N4O2
Candidate SMILES
Cc1nccn1CC1CCc2c(c3ccccc3n2N=O)C1=O

Interpretation: A structural alert alone does not establish that a nitrosamine forms. Evaluate nitrite sources, amine reagents, pH, temperature, process sequence, purge and analytical evidence.

05India status for this compound

These results apply only to this exact compound name and CAS number. Confirm the current official instruments before making a regulatory decision.

NDPS / RCSNO EXACT MATCH FOUNDNo CAS number is available for an exact comparison.
SCOMETNO EXACT REVIEWED CAS MATCHNo CAS number is available for an exact comparison.
Review date2026-08-01Recheck the current official instruments for the material, concentration, activity and date in question.

06Names and relationships

Associated parent compound

No parent compound is listed.

Other names

No synonyms are listed.

Related records from the same parent family

No related records are linked by parent name.

07Documented history

Dated discovery, occurrence, use and issue claims are published only when a suitable primary or government source is available.

No dated history available

No verified discovery, first report, occurrence, use or issue event is currently available for this identity.

08Sources