CompoundList
Sign in
Oncology and immunology drugs

Leflunomide

Also known as Arava, Leflunomida, 5-methyl-N-[4-(trifluoromethyl)phenyl]-1,2-oxazole-4-carboxamide

CAS 75706-12-6Formula C12H9F3N2O2Molar mass 270.21 g/molEC 616-254-6
GHS signal word: Danger. Pictograms: Acute toxicity (severe), Harmful or irritant 135 suppliers listed Drug substance
Get quotes Compare 135 suppliers
Leflunomide chemical structure, C12H9F3N2O2, CAS 75706-12-6
2D chemical structure

Key facts

What buyers check first

All properties
Appearance
Crystals from toluene
Melting point
166.5 °C
Solubility
In water, 153 mg/L at 25 °C /Estimated/
HS code
293499
Category
Oncology and immunology drugs
Illustrative photo, closed jumbo bulk bags in a warehouse in a warehouse
Typical packagingIllustrative packaging image, not the actual product

What is Leflunomide?

Plain description, key identifiers and synonyms

Leflunomide is a monocarboxylic acid amide obtained by formal condensation of the carboxy group of 5-methyl-1,2-oxazole-4-carboxylic acid with the anilino group of 4-(trifluoromethyl)aniline. The prodrug of teriflunomide. It has a role as an antiparasitic agent, a non-steroidal anti-inflammatory drug, an antineoplastic agent, an immunosuppressive agent, an EC 3.1.3.16 (phosphoprotein phosphatase) inhibitor, a tyrosine kinase inhibitor, a prodrug, a hepatotoxic agent, an EC 1.3.98.1 [dihydroorotate oxidase (fumarate)] inhibitor and a pyrimidine synthesis inhibitor. It is a monocarboxylic acid amide, a member of isoxazoles and a member of (trifluoromethyl)benzenes.

Identifiers

Registry numbers, names and line notations, tap to copy

IUPAC name
5-methyl-N-[4-(trifluoromethyl)phenyl]-1,2-oxazole-4-carboxamide
CAS number
75706-12-6 CAS number cross-checked
EC number
616-254-6
Molecular formula
C12H9F3N2O2
UNII
G162GK9U4W
MDL number
MFCD00867593
InChIKey
VHOGYURTWQBHIL-UHFFFAOYSA-N
InChI
InChI=1S/C12H9F3N2O2/c1-7-10(6-16-19-7)11(18)17-9-4-2-8(3-5-9)12(13,14)15/h2-6H,1H3,(H,17,18)
SMILES (canonical and isomeric)
CC1=C(C=NO1)C(=O)NC2=CC=C(C=C2)C(F)(F)F

Synonyms

  • Arava
  • Leflunomida
  • 5-methyl-N-[4-(trifluoromethyl)phenyl]-1,2-oxazole-4-carboxamide
  • Leflunomidum
  • Repso
  • leflunomide medac
  • Leflunomide teva
  • 5-Methylisoxazole-4-carboxylic acid (4-trifluoromethyl)anilide
  • Leflunomide winthrop
  • SULOL
  • Leflunomide ratiopharm
  • 5-Methyl-N-(4-(trifluoromethyl)phenyl)-4-isoxazolecarboxamide
  • alpha,alpha,alpha-Trifluoro-5-methyl-4-isoxazolecarboxy-p-toluidide
  • 4-Isoxazolecarboxamide, 5-methyl-N-[4-(trifluoromethyl)phenyl]-
  • 5-methyl-N-[4-(trifluoromethyl)phenyl]-4-isoxazolecarboxamide
  • 4-Isoxazolecarboxamide, 5-methyl-N-(4-(trifluoromethyl)phenyl)-
  • N-(4-(Trifluoromethyl)phenyl) 5 methylisoxazole-4-carboxamide
  • 5-methyl-N-(4-(trifluoromethyl)phenyl)-1,2-oxazole-4-carboxamide
  • N-(4-trifluoromethyphenyl)-5-methylisoxazole-4-carboxamide
  • lefunamide
  • HWA 486
  • 5-methyl-N-(4-(trifluoromethyl)phenyl)isoxazole-4-carboxamide
  • Arava (TN)
  • 5-methyl-N-[4-(trifluoromethyl)phenyl]isoxazole-4-carboxamide
  • SU 101
Show all 33 synonyms
  • 5-Methylisoxazole-4-(4-trifluoromethyl)carboxanilide
  • SU 101 (pharmaceutical)
  • Lefunomide [Inn-Spanish]
  • 5-Methylisoxazole-4-(4-trifluoromethylcarboxanilide)
  • Arabloc
  • Leflunomide CRS
  • N-(4'-Trifluoromethylphenyl)-5-methylisoxazole-4-carboxamide
  • Leflunomide (Standard)

Physical and chemical properties

Measured values and descriptors computed from the structure

Physical and chemical properties

Measured values, check the supplier specification for your grade

Appearance
Crystals from tolueneexp.
Melting point
166.5 °Cexp.
Solubility
In water, 153 mg/L at 25 °C /Estimated/exp.
Vapour pressure
1.25 × 10⁻⁶ mm Hg at 25 °C /Estimated/exp.

Values vary by grade. Ask suppliers for the COA or TDS of the batch you buy.

Computed descriptors

Calculated from the structure, useful for screening and formulation

Molecular weight
270.21 g/molcalc.
Exact mass
270.0616 Dacalc.
LogP (octanol/water)
3.25calc.
Topological polar surface area
55.13 Ųcalc.
Hydrogen bond donors
1calc.
Hydrogen bond acceptors
3calc.
Rotatable bonds
2calc.
Heavy atoms
19calc.
Rings
2calc.
Aromatic rings
2calc.
Fraction sp3 carbons
0.17calc.
Formal charge
0calc.
Stereocentres
0calc.
Lipinski rule of five
Passes (0 violations)calc.

Calculated for screening. Confirm critical figures with the supplier.

Murcko scaffold

The ring system that remains when every side chain is removed

Murcko scaffold of this chemical, O=C(Nc1ccccc1)c1cnoc1

O=C(Nc1ccccc1)c1cnoc1

2 rings, 14 atoms, the N-Phenyl-4-isoxazolecarboxamide ring system.

159 other chemicals share this scaffold

Safety and hazards

GHS classification summary, not a safety data sheet

GHS signal word
Danger
GHS06: Acute toxicity (severe)
Acute toxicity (severe)
GHS07: Harmful or irritant
Harmful or irritant

Hazard statements

  • H301Toxic if swallowed.
  • H315Causes skin irritation.
  • H319Causes serious eye irritation.
  • H335May cause respiratory irritation.
Precautionary statements (19)
  • P261Avoid breathing dust, fume, gas, mist, vapours or spray.
  • P264Wash skin thoroughly after handling.
  • P264 + P265Wash skin thoroughly after handling. Do not touch eyes.
  • P270Do not eat, drink or smoke when using this product.
  • P271Use only outdoors or in a well-ventilated area.
  • P280Wear protective gloves, protective clothing, eye protection and face protection.
  • P301 + P316If swallowed: Get emergency medical help immediately.
  • P302 + P352If on skin: Wash with plenty of water.
  • P304 + P340If inhaled: Remove person to fresh air and keep comfortable for breathing.
  • P305 + P351 + P338If in eyes: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
  • P319Get medical help if you feel unwell.
  • P321Specific treatment (see supplemental first aid instructions on the label).
  • P330Rinse mouth.
  • P332 + P317If skin irritation occurs: Get medical help.
  • P337 + P317If eye irritation persists: Get medical help.
  • P362 + P364Take off contaminated clothing. And wash it before reuse.
  • P403 + P233Store in a well-ventilated place. Keep container tightly closed.
  • P405Store locked up.
  • P501Dispose of contents and container in accordance with local regulations.

GHS classification summary, not a safety data sheet (SDS). Classifications can differ by supplier, grade and concentration. Always check the supplier's SDS.

Full safety data and first aid

Leflunomide suppliers

Sponsored listings first, then the documented ranking: membership, verification, replies, completeness, freshness and ratings

All 135 suppliers
30 of 30 offers

Suppliers marked Unclaimed profile have not claimed their profile yet. They are not verified by CompoundList, their offers are price on request and details may have changed, so please confirm them with the supplier. Company representatives can claim a profile with a business email on the company's own website domain. Our team verifies each claim and sends the result by email.

Where suppliers are based

135 suppliers in 24 countries

Send one request to many suppliers

Choose up to 10 suppliers or let us match your request. Compare quotes side by side, free.

Choose suppliersPost a request

Leflunomide price

Indicative price range per kg from live supplier offers

No published prices right now

Suppliers quote this chemical on request. Send one free request and compare quotes side by side.

Get latest price

Uses and applications

What the substance is used for, by industry and function

Medication: antirheumatic.

Pharmacological actions

  • Enzyme Inhibitors
  • Immunosuppressive Agents

Roles

  • aetiopathogenetic role
  • anti-HIV agent
  • anti-inflammatory agent
  • anti-inflammatory drug
  • antiinfective agent
  • antimicrobial agent
  • antineoplastic agent
  • antiparasitic agent
  • antirheumatic drug
  • antiviral agent
  • enzyme inhibitor
  • hepatotoxic agent
  • immunomodulator
  • immunosuppressive agent
  • non-steroidal anti-inflammatory drug
  • ophthalmology drug
  • pathway inhibitor
  • pharmaceutical
  • pro-agent
  • prodrug
  • protein kinase inhibitor
  • pyrimidine synthesis inhibitor
  • tyrosine kinase inhibitor

Pharmacology

Leflunomide is an Antirheumatic Agent.

Regulatory status

Inventories, regulations and trade controls that list this substance

Health and food

  • Active ingredient in FDA approved drug labels

HS code and trade data

Customs classification and reported world trade statistics

Global trade

World import and export statistics for the HS code Leflunomide is traded under.

HS 2934.99Indicative HS code

Nucleic acids and their salts, other heterocyclic compounds, not elsewhere classified in heading 2934

World exports in 2024
$26.7B
+15.0% vs 2023, imports $26.3B
2019 to 2024
Top exporters
  1. Ireland26.3%
  2. China15.7%
  3. Singapore10.3%
Top importers
  1. United States24.5%
  2. Germany23.1%
  3. Japan4.5%
Reported customs values in USD, not prices.Full trade data

The HS code shown for Leflunomide is indicative (it was assigned by structure rules). Confirm the classification with your customs broker before shipping.

Frequently asked questions

Quick answers about Leflunomide, based on the data on this page

What is Leflunomide?

Leflunomide is a monocarboxylic acid amide obtained by formal condensation of the carboxy group of 5-methyl-1,2-oxazole-4-carboxylic acid with the anilino group of 4-(trifluoromethyl)aniline. The prodrug of teriflunomide.

What is the CAS number of Leflunomide?

The CAS registry number of Leflunomide is 75706-12-6.

What is the molecular formula and weight of Leflunomide?

The molecular formula of Leflunomide is C12H9F3N2O2 and its molar mass is 270.21 g/mol.

What is Leflunomide used for?

Medication: antirheumatic.

Is Leflunomide hazardous?

Leflunomide carries the GHS signal word "Danger". Main hazards: toxic if swallowed, causes skin irritation, causes serious eye irritation. This summary is not an SDS, always read the supplier safety data sheet.

What is the HS code of Leflunomide?

Leflunomide is usually classified under HS code 293499 (Nucleic acids and their salts, whether or not chemically defined, other heterocyclic…). This is indicative, confirm it with your customs broker before shipping.

Where can I buy Leflunomide?

CompoundList lists 135 suppliers of Leflunomide in United States, China, India, Germany and 20 more. Send one free request to get and compare quotes. Your contact details stay private until you accept a quote.

Where can I buy Leflunomide in India?

17 suppliers in India list Leflunomide on CompoundList. Filter the suppliers list by country and send a request to compare prices, grades and delivery times.

What is the price of Leflunomide?

Suppliers quote Leflunomide on request because prices depend on grade, purity, quantity and destination. A free request on CompoundList gets you several quotes to compare.

Guides for buyers

Practical guides that help when you source, ship or handle Leflunomide

Get quotes for Leflunomide

Post one free request with your grade, quantity and destination. Matching suppliers send quotes you can compare side by side.
Post a request Sell Leflunomide
Data last updated 7 Oct 2026. Details may have changed, please confirm them with the supplier. Report an error on this page
Embed this structure on your websiteShow code

Paste this code into your page to show the 2D structure of Leflunomide with a 3D view, its CAS number where known and a link back to this page. Free to use with the link kept.

<iframe src="https://www.compoundlist.com/embed/structure/leflunomide-75706-12-6" title="Leflunomide structure on CompoundList" width="360" height="420" style="border:1px solid #E7E2DA;border-radius:12px;max-width:100%" loading="lazy" referrerpolicy="strict-origin-when-cross-origin"></iframe>
Preview the embed

Explore more in Oncology and immunology drugs or HS code 293499

135 suppliers
Free quotes, contact stays private
Get quotes