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Oncology and immunology drugs

Letrozole

Also known as Letrozol, CGS 20267, 4-[(4-cyanophenyl)-(1,2,4-triazol-1-yl)methyl]benzonitrile

CAS 112809-51-5Formula C17H11N5Molar mass 285.31 g/molEC 675-034-8
GHS signal word: Danger. Pictograms: Harmful or irritant, Serious health hazard 164 suppliers listed Drug substance
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Letrozole chemical structure, C17H11N5, CAS 112809-51-5
2D chemical structure

Key facts

What buyers check first

All properties
Appearance
White to yellowish crystalline powder
Melting point
181 to 183
Solubility
Freely soluble in dichloromethane, slightly soluble in ethanol, practically insoluble in…
HS code
293399
Category
Oncology and immunology drugs
Illustrative photo, off-white crystalline powder in fibre drums in a warehouse
Typical packagingIllustrative packaging image, not the actual product

What is Letrozole?

Plain description, key identifiers and synonyms

Letrozole is a nitrile and a member of triazoles. It has a role as an antineoplastic agent and an EC 1.14.14.14 (aromatase) inhibitor.

Identifiers

Registry numbers, names and line notations, tap to copy

IUPAC name
4-[(4-cyanophenyl)-(1,2,4-triazol-1-yl)methyl]benzonitrile
CAS number
112809-51-5 CAS number cross-checked
EC number
675-034-8
Molecular formula
C17H11N5
UNII
7LKK855W8I
MDL number
MFCD00866241
InChIKey
HPJKCIUCZWXJDR-UHFFFAOYSA-N
InChI
InChI=1S/C17H11N5/c18-9-13-1-5-15(6-2-13)17(22-12-20-11-21-22)16-7-3-14(10-19)4-8-16/h1-8,11-12,17H
SMILES (canonical and isomeric)
C1=CC(=CC=C1C#N)C(C2=CC=C(C=C2)C#N)N3C=NC=N3

Synonyms

  • Letrozol
  • CGS 20267
  • 4-[(4-cyanophenyl)-(1,2,4-triazol-1-yl)methyl]benzonitrile
  • Benzonitrile, 4,4'-(1H-1,2,4-triazol-1-ylmethylene)bis-
  • 4,4'-(1H-1,2,4-Triazol-1-ylmethylene)dibenzonitrile
  • 4-[(4-Cyanophenyl)(1H-1,2,4-triazol-1-yl)methyl]benzonitrile
  • Kisqali femara co-pack component letrozole
  • letrozolum
  • 4-((4-cyanophenyl)-(1,2,4-triazol-1-yl)methyl)benzonitrile
  • 4-((4-cyanophenyl)(1H-1,2,4-triazol-1-yl)methyl)benzonitrile
  • Letrozole Tablets
  • 4,4'-(1H-1,2,4-triazol-1-yl-methylene)-bis(benzonitrile)
  • 4,4'-(1H-1,2,4triazol-1-ylmethylene)dibenzonitrile
  • 4,4'-((1h-1,2,4-triazol-1-yl)methylene)dibenzonitrile
  • 4,4'-(1h-1,2,4-triazol-1-ylmethylene)bisbenzonitrile
  • 4,4'-(1H-1,2,4-triazol-1-ylmethanediyl)dibenzonitrile
  • 1-[bis(4-cyanophenyl)methyl]-1,2,4-triazole
  • Letoval
  • Letrazole
  • 4,4'-[(1H-1,2,4-Triazol-1-yl)methylene]dibenzonitrile
  • Letrozole (JAN/USP/INN)
  • 4,4'-(1h-1,2,4-triazol-1-ylmethylene)bis-benzonitrile
  • Letrozole?
  • Letrozole CRS
  • Letrozole (Standard)
Show all 27 synonyms
  • 4,4'-(1h-1,2,4-triazol-1-ylmethylene) bis-benzonitrile
  • 1-[Bis-(4-cyanophenyl)methyl]-1,2,4-triazole

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 yellowish crystalline powderexp.
Odour
Practically odorlessexp.
Melting point
181 to 183exp.
Solubility
Freely soluble in dichloromethane, slightly soluble in ethanol, 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
285.31 g/molcalc.
Exact mass
285.1014 Dacalc.
LogP (octanol/water)
2.66calc.
Topological polar surface area
78.29 Ųcalc.
Hydrogen bond donors
0calc.
Hydrogen bond acceptors
4calc.
Rotatable bonds
3calc.
Heavy atoms
22calc.
Rings
3calc.
Aromatic rings
3calc.
Fraction sp3 carbons
0.06calc.
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, c1ccc(C(c2ccccc2)n2cncn2)cc1

c1ccc(C(c2ccccc2)n2cncn2)cc1

3 rings, 18 atoms, the 1-Benzhydryl-1,2,4-triazole ring system.

19 other chemicals 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

Hazard statements

  • H315Causes skin irritation.
  • H319Causes serious eye irritation.
  • H351Suspected of causing cancer.
  • H360May damage fertility or the unborn child.
  • H373May cause damage to organs through prolonged or repeated exposure.
Precautionary statements (15)
  • P203Obtain, read and follow all safety instructions before use.
  • P260Do not breathe dust, fume, gas, mist, vapours or spray.
  • P264Wash skin thoroughly after handling.
  • P264 + P265Wash skin thoroughly after handling. Do not touch eyes.
  • P280Wear protective gloves, protective clothing, eye protection and face protection.
  • P302 + P352If on skin: Wash with plenty of water.
  • 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.
  • P319Get medical help if you feel unwell.
  • P321Specific treatment (see supplemental first aid instructions on the label).
  • 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.
  • 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

Letrozole suppliers

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

All 164 suppliers
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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

164 suppliers in 29 countries

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Letrozole 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.

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Uses and applications

What the substance is used for, by industry and function

Antineoplastic.

Therapeutic category: Antineoplastic.

Use classes: Pharmaceuticals.

Industries and functions

Pharmacological actions

  • Antineoplastic Agents
  • Aromatase Inhibitors

Roles

  • antineoplastic agent
  • bone density conservation agent
  • enzyme inhibitor
  • pharmaceutical

Functional uses

  • Pharmaceutical

Pharmacology

Letrozole is an Aromatase Inhibitor. The mechanism of action of letrozole 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 Letrozole is traded under.

HS 2933.99Indicative HS code

Heterocyclic compounds with nitrogen hetero-atom(s) only, other

World exports in 2024
$12.1B
−31.0% vs 2023, imports $28.8B
2019 to 2024
Top exporters
  1. China30.5%
  2. India * partner reported16.3%
  3. Ireland9.0%
Top importers
  1. Slovenia31.7%
  2. Italy24.2%
  3. United States5.0%

* Partner reported figures, a lower bound.

Reported customs values in USD, not prices.Full trade data

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

Frequently asked questions

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

What is Letrozole?

Letrozole is a nitrile and a member of triazoles. It has a role as an antineoplastic agent and an EC 1.14.14.14 (aromatase) inhibitor.

What is the CAS number of Letrozole?

The CAS registry number of Letrozole is 112809-51-5.

What is the molecular formula and weight of Letrozole?

The molecular formula of Letrozole is C17H11N5 and its molar mass is 285.31 g/mol.

What is Letrozole used for?

Antineoplastic. Therapeutic category: Antineoplastic. Use classes: Pharmaceuticals.

Is Letrozole hazardous?

Letrozole carries the GHS signal word "Danger". Main hazards: causes skin irritation, causes serious eye irritation, suspected of causing cancer. This summary is not an SDS, always read the supplier safety data sheet.

What is the HS code of Letrozole?

Letrozole is usually classified under HS code 293399 (Heterocyclic compounds with nitrogen hetero-atom(s) only, other). This is indicative, confirm it with your customs broker before shipping.

Where can I buy Letrozole?

CompoundList lists 164 suppliers of Letrozole in China, United States, India, United Kingdom and 25 more. Send one free request to get and compare quotes. Your contact details stay private until you accept a quote.

Where can I buy Letrozole in India?

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

What is the price of Letrozole?

Suppliers quote Letrozole 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 Letrozole

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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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