C4H3FN2O2
130.08 g/mol
APIDanger
5-Fluorouracil
CAS51-21-8EC200-085-6
Category
API
Compound Class
Heterocycle
Primary Use
Pharmaceutical Raw Material
5-Fluorouracil is a fluorinated pyrimidine compound used as a pharmaceutical raw material in the manufacturing of antineoplastic medications. It is a low-molecular-weight, aromatic heterocyclic compound with two hydrogen bond donors and two hydrogen bond acceptors.
Antineoplastic pharmaceutical raw materialAntimetabolite compound for pharmaceutical manufacturing
Content scope: Information here supports chemical identification and industrial supply, research, and manufacturing contexts. It is not a therapeutic claim, medical advice, or drug-use instructions.
Restricted or banned substances
Substances on this list are banned or restricted under the named regulation. This page is a compliance reference — verify your obligations under applicable law.
Relevant lists:California Proposition 65
CAS 51-21-8
Related Compounds
ReferenceSame Category
Tiratricol
CAS51-24-1
pharmaceutical raw material
ReferenceSame Category
Isoproterenol hydrochloride
CAS51-30-9
pharmaceutical raw material
ReferenceSame Category
L-scopolamine
CAS51-34-3
pharmaceutical raw material
ReferenceSame Category
Hydroxyproline
CAS51-35-4
pharmaceutical raw material
Safety Reference
Danger
H301Toxic if swallowed
H312Harmful in contact with skin
H315Causes skin irritation
H319Causes serious eye irritation
H335May cause respiratory irritation
H340May cause genetic defects
H360May damage fertility or the unborn child
H412Harmful to aquatic life with long lasting effects
H341Suspected of causing genetic defects
H372Causes damage to organs through prolonged or repeated exposure
Regulatory Compliance1
- California Proposition 65USRegulation
Customs Tariff Classification
The international HS code for 5-Fluorouracil (CAS 51-21-8) is 2933.59.
HS code (international, 6-digit)
2933.59
EU CN code (8-digit)
2933 59 95
Classification per the EU customs inventory ECICS (2026-07 snapshot, HS 2022). National tariff lines and product form can affect the final classification.
Identifiers
IUPAC Name
5-fluoro-1H-pyrimidine-2,4-dione
InChIKey
GHASVSINZRGABV-UHFFFAOYSA-N
SMILES
C1=C(C(=O)NC(=O)N1)F
Synonyms (129)
- 5-FU
- U-8953
- URF
- Fluorouracil (JP18/USP/INN)
- Fluorouracil, British Pharmacopoeia (BP)
- Fluorouracil, European Pharmacopoeia (EP)
- Fluorouracil, United States Pharmacopeia (USP)
- Fluorouracil, meets USP testing specifications
- Fluorouracil; 5-Fluoropyrimidine-2,4(1H,3H)-dione; Flucytosine Imp. A (EP); Flucytosine Impurity A
- Fluorouracil; Flucytosine EP Impurity A
- Fluorouracilo [INN-Spanish]
- Fluorouracilum [INN-Latin]
- 1upf
- 2,4-Dioxo-5-fluoropryimidine
- 2,4-Dioxo-5-fluoropyrimidine
- 5 FU Lederle
- 5 FU medac
- 5 Fluorouracil biosyn
- 5 Fluorouracilum
- 5 HU Hexal
- 5-FU (TN)
- 5-Faracil
- 5-Fluor-2,4-pyrimidindiol
- 5-Fluoracil
- 5-Fluoracil [German]
- 5-Fluoracyl
- 5-Fluoro-2,4-pyrimidinedione
- 5-Fluoropyrimidin-2,4-diol
- 5-Fluoropyrimidine-2,4-dione
- 5-Fluorouracil
- 5-Fluorouracil (5-FU)
- 5-Fluorouracil (Standard)
- 5-Fluoruracil
- 5-Fluoruracil [German]
- 5-Fluracil
- 5-Ftouracyl
- 5-florouracil
- 5-fluoro-2,4-dioxo-pyrimidin
- 5-fluoropyrimidine-2,4-diol
- 5-fluorouacil
- 5-fluorourasil
- 5-fluorpyrimidin-2,4-diol
- 5F-uracil
- AccuSite
- Adrucil
- Adrucil (Fluorouracil)
- Adrucil (ICN)
- Adrucil (TN)
- Arumel
- Carac
- Carac (TN)
- Carzonal
- Cinco FU
- Dakota, Fluorouracile
- EMTRICITABINE IMPURITY F
- Effluderm
- Effluderm (free base)
- Efudex
- Efudix
- Efurix
- FLUCYTOSINE IMPURITY A
- FLUOROURACIL [MART.]
- Fluoro Uracile ICN
- Fluoro-uracil roche
- Fluoro-uracile
- Fluoroblastin
- Fluoroplex
- Fluoroplex (TN)
- Fluorouracil CRS
- Fluorouracil Cream
- Fluorouracil GRY
- Fluorouracil RS
- Fluorouracil, 5-
- Fluorouracilo
- Fluorouracilum
- Fluorouricil
- Fluoruracil
- Fluouracil
- Flurablastin
- Fluracil
- Fluracilum
- Fluri
- Fluril
- Fluro Uracil
- Fluroblastin
- Flurodex
- Folfox component fluorouracil
- Ftoruracil
- Haemato fu
- Kecimeton
- Phthoruracil
- Phtoruracil
- Queroplex
- Ro 2-9757
- Timazin
- Tolak
- Ulup
- Uracil, 5-fluoro-
- fluorouracil