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Oncology and immunology drugs

Exemestane

Also known as Aromasin, 6-Methyleneandrosta-1,4-diene-3,17-dione, Exemestano

CAS 107868-30-4Formula C20H24O2Molar mass 296.41 g/molEC 643-090-2
GHS signal word: Danger. Pictograms: Harmful or irritant, Serious health hazard, Hazardous to the environment 100 suppliers listed Drug substance
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Exemestane chemical structure, C20H24O2, CAS 107868-30-4
2D chemical structure

Key facts

What buyers check first

All properties
Appearance
White to slightly yellow crystalline powder
Melting point
188 to 191
Solubility
Freely soluble in N,N-dimethylformamide, soluble in methanol, practically insoluble in w…
HS code
293729
Category
Oncology and immunology drugs
Illustrative photo, off-white crystalline powder in an HDPE jar on a laboratory bench
Typical packagingIllustrative packaging image, not the actual product

What is Exemestane?

Plain description, key identifiers and synonyms

Exemestane is a 17-oxo steroid that is androsta-1,4-diene-3,17-dione in which the hydrogens at position 6 are replaced by a double bond to a methylene group. A selective inhibitor of the aromatase (oestrogen synthase) system, it is used in the treatment of advanced breast cancer. It has a role as an antineoplastic agent, a xenobiotic, an EC 1.14.14.14 (aromatase) inhibitor and an environmental contaminant. It is a 17-oxo steroid and a 3-oxo-Delta(1),Delta(4)-steroid. It derives from a hydride of an androstane.

Identifiers

Registry numbers, names and line notations, tap to copy

IUPAC name
(8R,9S,10R,13S,14S)-10,13-dimethyl-6-methylidene-7,8,9,11,12,14,15,16-octahydrocyclopenta[a]phenanthrene-3,17-dione
CAS number
107868-30-4 CAS number cross-checked
EC number
643-090-2
Molecular formula
C20H24O2
UNII
NY22HMQ4BX
MDL number
MFCD00866994
InChIKey
BFYIZQONLCFLEV-DAELLWKTSA-N
InChI
InChI=1S/C20H24O2/c1-12-10-14-15-4-5-18(22)20(15,3)9-7-16(14)19(2)8-6-13(21)11-17(12)19/h6,8,11,14-16H,1,4-5,7,9-10H2,2-3H3/t14-,15-,16-,19+,20-/m0/s1
Canonical SMILES
C=C1CC2C(CCC3(C)C(=O)CCC23)C2(C)C=CC(=O)C=C12
Isomeric SMILES
C[C@]12CC[C@H]3[C@H]([C@@H]1CCC2=O)CC(=C)C4=CC(=O)C=C[C@]34C

Synonyms

  • Aromasin
  • 6-Methyleneandrosta-1,4-diene-3,17-dione
  • Exemestano
  • Exemestanum
  • Androsta-1,4-diene-3,17-dione, 6-methylene-
  • (8R,9S,10R,13S,14S)-10,13-dimethyl-6-methylidene-7,8,9,11,12,14,15,16-octahydrocyclopenta[a]phenanthrene-3,17-dione
  • examestane
  • (1S,2R,10R,11S,15S)-2,15-dimethyl-8-methylidenetetracyclo(8.7.0.0^(2,7).0^(11,15))heptadeca-3,6-diene-5,14-dione
  • (1S,2R,10R,11S,15S)-2,15-dimethyl-8-methylidenetetracyclo[8.7.0.0^{2,7}.0^{11,15}]heptadeca-3,6-diene-5,14-dione
  • (8R,9S,10R,13S,14S)-10,13-dimethyl-6-methylidene-7,8,9,11,12,14,15,16-octahydrocyclopenta(a)phenanthrene-3,17-dione
  • Fce 24304
  • Exemestan
  • 6-Methylene-androsta-1,4-diene-3,17-dione
  • (8R,9S,10R,13S,14S)-10,13-dimethyl-6-methylene-7,8,9,10,11,12,13,14,15,16-decahydro-3H-cyclopenta[a]phenanthrene-3,17(6H)-dione
  • Exemestane (Standard)
  • 6-Methylenandrosta-1,4-diene-3,17-dione
  • Aromasine
  • Aromasil
  • 6-methylideneandrosta-1,4-diene-3,17-dione
  • Nikidess
  • (8alpha,10alpha,13alpha)-6-Methylideneandrosta-1,4-Diene-3,17-Dione
  • Aromasin (TN)
  • Exemestane (JAN/USP/INN)
  • Aromasin,
  • Exemestane CRS
Show all 29 synonyms
  • Androsta-1,4-diene-3,17-dione, 6-methylene-, 6-Methyleneandrosta-1,4-diene-3,17-dione, Aromasil, Aromasin, Exemestane, FCE 24304
  • Exemestane, aromasin
  • PNU 155971
  • (8R,9S,10R,13S,14S)-10,13-Dimethyl-6-methylene-7,8,9,11,12,13,15,16-octahydro-6H-cyclopenta[a]phenanthrene-3,17(10H,14H)-dione

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
White to slightly yellow crystalline powderexp.
Melting point
188 to 191exp.
Solubility
Freely soluble in N,N-dimethylformamide, soluble in methanol, practically insoluble in waterexp.

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
296.41 g/molcalc.
Exact mass
296.1776 Dacalc.
LogP (octanol/water)
4.03calc.
Topological polar surface area
34.14 Ųcalc.
Hydrogen bond donors
0calc.
Hydrogen bond acceptors
2calc.
Rotatable bonds
0calc.
Heavy atoms
22calc.
Rings
4calc.
Aromatic rings
0calc.
Fraction sp3 carbons
0.6calc.
Formal charge
0calc.
Stereocentres
5calc.
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, C=C1CC2C(CCC3C(=O)CCC32)C2C=CC(=O)C=C12

C=C1CC2C(CCC3C(=O)CCC32)C2C=CC(=O)C=C12

4 rings, 20 atoms.

1 other chemical share this scaffold

Safety and hazards

GHS classification summary, not a safety data sheet

GHS signal word
Danger
GHS07: Harmful or irritant
Harmful or irritant
GHS08: Serious health hazard
Serious health hazard
GHS09: Hazardous to the environment
Hazardous to the environment

Hazard statements

  • H319Causes serious eye irritation.
  • H360May damage fertility or the unborn child.
  • H411Toxic to aquatic life with long lasting effects.
Precautionary statements (10)
  • P203Obtain, read and follow all safety instructions before use.
  • P264 + P265Wash skin thoroughly after handling. Do not touch eyes.
  • P273Avoid release to the environment.
  • P280Wear protective gloves, protective clothing, eye protection and face protection.
  • P305 + P351 + P338If in eyes: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
  • P318If exposed or concerned, get medical advice.
  • P337 + P317If eye irritation persists: Get medical help.
  • P391Collect spillage.
  • 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

Exemestane suppliers

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All 100 suppliers
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Where suppliers are based

100 suppliers in 21 countries

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Exemestane price

Indicative price range per kg from live supplier offers

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Uses and applications

What the substance is used for, by industry and function

Therapeutic category: Antineoplastic (hormonal).

Use classes: Pharmaceuticals.

Pharmacological actions

  • Antineoplastic Agents
  • Aromatase Inhibitors

Roles

  • agonist
  • androgen
  • antineoplastic agent
  • environmental contaminant
  • enzyme inhibitor
  • hormone
  • molecular messenger
  • pharmaceutical
  • sex hormone
  • xenobiotic

Functional uses

  • Pharmaceutical

Pharmacology

Exemestane is an Aromatase Inhibitor. The mechanism of action of exemestane is as an Aromatase Inhibitor.

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 Exemestane is traded under.

HS 2937.29Indicative HS code

Steroidal hormones, their derivatives and structural analogues, other

World exports in 2024
$2.32B
+5.7% vs 2023, imports $2.41B
2019 to 2024
Top exporters
  1. Belgium25.3%
  2. United States24.9%
  3. China13.0%
Top importers
  1. Italy18.0%
  2. Canada13.0%
  3. Belgium12.2%
Reported customs values in USD, not prices.Full trade data

The HS code shown for Exemestane is indicative (it is known at chapter level only). Confirm the classification with your customs broker before shipping.

Frequently asked questions

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

What is Exemestane?

Exemestane is a 17-oxo steroid that is androsta-1,4-diene-3,17-dione in which the hydrogens at position 6 are replaced by a double bond to a methylene group. A selective inhibitor of the aromatase (oestrogen synthase) system, it is used in the treatment of advanced breast cancer.

What is the CAS number of Exemestane?

The CAS registry number of Exemestane is 107868-30-4.

What is the molecular formula and weight of Exemestane?

The molecular formula of Exemestane is C20H24O2 and its molar mass is 296.41 g/mol.

What is Exemestane used for?

Therapeutic category: Antineoplastic (hormonal). Use classes: Pharmaceuticals.

Is Exemestane hazardous?

Exemestane carries the GHS signal word "Danger". Main hazards: causes serious eye irritation, may damage fertility or the unborn child, toxic to aquatic life with long lasting effects. This summary is not an SDS, always read the supplier safety data sheet.

What is the HS code of Exemestane?

Exemestane is usually classified under HS code 293729 (Steroidal hormones, their derivatives and structural analogues, other). This is indicative, confirm it with your customs broker before shipping.

Where can I buy Exemestane?

CompoundList lists 100 suppliers of Exemestane in China, United States, India, Spain and 17 more. Send one free request to get and compare quotes. Your contact details stay private until you accept a quote.

Where can I buy Exemestane in India?

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

What is the price of Exemestane?

Suppliers quote Exemestane 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 Exemestane

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Data last updated 7 Oct 2026. Details may have changed, please confirm them with the supplier. Report an error on this page
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