5-fluorouracil
A nucleobase analogue that is uracil in which the hydrogen at position 5 is replaced by fluorine. It is an antineoplastic agent which acts as an antimetabolite - following conversion to the active deoxynucleotide, it inhibits DNA synthesis (by blocking the conversion of deoxyuridylic acid to thymidylic acid by the cellular enzyme thymidylate synthetase) and so slows tumour growth. — ChEBI
Safety documents & references
1 indexed referencesFind a product-specific SDS
Safety guides and government classification records are not a manufacturer’s SDS. Match supplier, product number, concentration, physical form, region and revision before using a document.
Identity & molecular properties
Source-linked values| CAS number | 51-21-8 | ChEBI ↗ |
| Molecular formula | C4H3FN2O2 | ChEBI ↗ |
| Molar mass | 130.078 g/mol | ChEBI ↗ |
| Monoisotopic mass | 130.01786 Da | ChEBI ↗ |
| Formal charge | 0 | ChEBI ↗ |
| ChEBI identifier | CHEBI:46345 | ChEBI ↗ |
Cross-source molecular data
PubChem| Molar mass | 130.08 g/mol | PubChem ↗ |
| Exact mass | 130.01785550 Da | PubChem ↗ |
| Computed XLogP | -0.9 | PubChem ↗ |
| Topological polar surface area (Ų) | 58.2 | PubChem ↗ |
| H-bond donors | 2 | PubChem ↗ |
| H-bond acceptors | 3 | PubChem ↗ |
| Rotatable bonds | 0 | PubChem ↗ |
PubChem computed values are shown separately from the ChEBI record. An exact InChIKey match was used to connect the records. Molecular descriptors do not describe a supplied product’s purity, particle size or performance.
Names & structural identifiers
Copy any identifier5-fluorouracil5-fluoropyrimidine-2,4(1H,3H)-dioneGHASVSINZRGABV-UHFFFAOYSA-NO=c1ncc(F)c(=O)n1InChI=1S/C4H3FN2O2/c5-2-1-6-4(9)7-3(2)8/h1H,(H2,6,7,8,9)Names & synonyms
Names are supplied by ChEBI. Trade names and related synonyms may describe a broader product context.
Classification & relationships
ChEBI ontologyRoles recorded in ChEBI
Database role annotations describe reported biological or chemical roles; they are not product approvals or recommendations for use.
Safety classification · Japan
NITE / Japanese government5-Fluorouracil · 22A4093
| Endpoint | Reported classification |
|---|---|
| Acute toxicity （Oral） | Category 3 |
| Germ cell mutagenicity | Category 2 |
| Reproductive toxicity | Category 1B |
| Specific target organ toxicity - Repeated exposure | Category 1 (digestive system, bone marrow, nervous system) |
Selected source-reported endpoints. Other endpoints, rationales and conditions remain in the original classification. Missing or unlisted information does not mean non-hazardous. This is not a global classification or transport decision.
Read the original NITE classificationMass ↔ amount of substance
Calculated from sourced massUses 130.078 g/mol from ChEBI. Assumes the substance described by this record; no purity or concentration correction is applied.
Elemental composition
Theoretical mass fractionsCONFHCalculated theoretical mass fractions from the reported formula and PubChem periodic-table atomic masses. These are not assay or purity results.
Research & patent references
Selected source associationsSources & record history
Checked 27 Sep 2026Release 255, 9 September 2026. ChEBI three-star (manually annotated) source entry. View original record ↗ · CC BY 4.0
PubCAS formats source data, connects references and computes explicitly labelled conversions. CAS cross-references are supplied by ChEBI; they do not constitute CAS verification or endorsement.