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Impurities and reference standards

Thymine

Also known as 5-methyluracil, 2,4-Dihydroxy-5-methylpyrimidine, Thymin

CAS 65-71-4Formula C5H6N2O2Molar mass 126.12 g/molEC 200-616-1
GHS signal word: Warning. Pictograms: Harmful or irritant 107 suppliers listed
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Thymine chemical structure, C5H6N2O2, CAS 65-71-4
2D chemical structure

Key facts

What buyers check first

All properties
CAS number
65-71-4
Formula
C5H6N2O2
Molar mass
126.12 g/mol
EC number
200-616-1
HS code
293359
Category
Impurities and reference standards

What is Thymine?

Plain description, key identifiers and synonyms

Thymine is a pyrimidine nucleobase that is uracil in which the hydrogen at position 5 is replaced by a methyl group. It has a role as a mouse metabolite, an Escherichia coli metabolite and a human metabolite. It is a pyrimidine nucleobase and a pyrimidone.

Identifiers

Registry numbers, names and line notations, tap to copy

IUPAC name
5-methyl-1H-pyrimidine-2,4-dione
CAS number
65-71-4 CAS number cross-checkedOther or deprecated CAS: 123430-67-1, 153445-43-3, 24523-96-4, 2792-47-4, 3059-73-2, 691841-57-3, 69497-78-5
EC number
200-616-1
Molecular formula
C5H6N2O2
UNII
QR26YLT7LT
MDL number
MFCD00006026
INCI name
THYMINE
InChIKey
RWQNBRDOKXIBIV-UHFFFAOYSA-N
InChI
InChI=1S/C5H6N2O2/c1-3-2-6-5(9)7-4(3)8/h2H,1H3,(H2,6,7,8,9)
SMILES (canonical and isomeric)
CC1=CNC(=O)NC1=O

Synonyms

  • 5-methyluracil
  • 2,4-Dihydroxy-5-methylpyrimidine
  • Thymin
  • Thymine anhydrate
  • 5-Methyl-1,2,3,4-tetrahydropyrimidine-2,4-dione
  • 2,4(1H,3H)-Pyrimidinedione, 5-methyl-
  • Thymin (purine base)
  • 5-methyl-1H-pyrimidine-2,4-dione
  • 5-methyl-2,4(1H,3H)-pyrimidinedione
  • 5 Methyluracil
  • 5-methylpyrimidine-2,4(1H,3H)-dione
  • 5-Methyl Uracil
  • Thymine-13c1
  • thymine-d4
  • 5-Methylpyrimidine-2,4(1H,3H)-dione (thymine)
  • Thymine-t
  • Zidovudine EP Impurity C
  • Thy
  • Thymine (VAN)
  • (3H)Methylthymidine
  • 5-methyl-1,3-dihydropyrimidine-2,4-dione
  • Methyl-3H thymidine
  • Thymine (8CI)
  • 5-methylpyrimidine-2,4-diol
  • 5-methyl-uracil
Show all 32 synonyms
  • Thymine (Standard)
  • Thymine, >=99%
  • 2,4(1H,3H)-Pyrimidinedione, 5-methyl- (9CI)
  • 5-Methyl-2,4-dioxypyrimidine
  • 2.6-Dioxy-5-methyl-pyrimidin
  • 2,4(1H,3H)-Pyrimidinedione, 5-methyl-, labeled with tritium
  • 2,3H)-Pyrimidinedione, 5-methyl-

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

No measured properties are recorded for this substance yet. Ask suppliers for a technical data sheet.

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
126.12 g/molcalc.
Exact mass
126.0429 Dacalc.
LogP (octanol/water)
-0.63calc.
Topological polar surface area
65.72 Ųcalc.
Hydrogen bond donors
2calc.
Hydrogen bond acceptors
2calc.
Rotatable bonds
0calc.
Heavy atoms
9calc.
Rings
1calc.
Aromatic rings
1calc.
Fraction sp3 carbons
0.2calc.
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=c1cc[nH]c(=O)[nH]1

O=c1cc[nH]c(=O)[nH]1

1 ring, 8 atoms, the Uracil ring system.

2,933 other chemicals share this scaffold

Safety and hazards

GHS classification summary, not a safety data sheet

GHS signal word
Warning
GHS07: Harmful or irritant
Harmful or irritant

Hazard statements

  • H319Causes serious eye irritation.
Precautionary statements (4)
  • P264 + P265Wash skin thoroughly after handling. Do not touch eyes.
  • 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.
  • P337 + P317If eye irritation persists: Get medical help.

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

Thymine suppliers

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

All 107 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

107 suppliers in 15 countries

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Thymine 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

Cosmetic ingredient, INCI name THYMINE(skin conditioning)

Roles

  • Escherichia coli metabolite
  • animal metabolite
  • bacterial metabolite
  • eukaryotic metabolite
  • human metabolite
  • mammalian metabolite
  • metabolite
  • mouse metabolite
  • prokaryotic metabolite

Functional uses

  • Softener and conditioner

Cosmetic functions

  • Skin conditioning

Regulatory status

Inventories, regulations and trade controls that list this substance

Health and food

  • EU cosmetic ingredient inventory

United States

  • TSCA inventory (USA)
    Status: Active in US commerce

HS code and trade data

Customs classification and reported world trade statistics

Global trade

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

HS 2933.59Indicative HS code

Compounds containing a pyrimidine ring (whether or not hydrogenated) or piperazine ring, other

World exports in 2024
$18.4B
+10.5% vs 2023, imports $24.8B
2019 to 2024
Top exporters
  1. Ireland43.6%
  2. Switzerland * partner reported26.3%
  3. China7.9%
Top importers
  1. Slovenia30.3%
  2. United States30.1%
  3. Germany15.3%

* Partner reported figures, a lower bound.

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

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

Frequently asked questions

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

What is Thymine?

Thymine is a pyrimidine nucleobase that is uracil in which the hydrogen at position 5 is replaced by a methyl group. It has a role as a mouse metabolite, an Escherichia coli metabolite and a human metabolite. It is a pyrimidine nucleobase and a pyrimidone.

What is the CAS number of Thymine?

The CAS registry number of Thymine is 65-71-4. Other or deprecated CAS numbers: 123430-67-1, 153445-43-3, 24523-96-4.

What is the molecular formula and weight of Thymine?

The molecular formula of Thymine is C5H6N2O2 and its molar mass is 126.12 g/mol.

What is Thymine used for?

Known uses and roles of Thymine include skin conditioning agents in cosmetics and personal care, escherichia coli metabolite, animal metabolite, bacterial metabolite, eukaryotic metabolite and 7 more.

Is Thymine hazardous?

Thymine carries the GHS signal word "Warning". Main hazards: causes serious eye irritation. This summary is not an SDS, always read the supplier safety data sheet.

What is the HS code of Thymine?

Thymine is usually classified under HS code 293359 (Compounds containing a pyrimidine ring (whether or not hydrogenated) or piperazine ring…). This is indicative, confirm it with your customs broker before shipping.

Where can I buy Thymine?

CompoundList lists 107 suppliers of Thymine in China, United States, Germany, United Kingdom and 11 more. Send one free request to get and compare quotes. Your contact details stay private until you accept a quote.

What is the price of Thymine?

Suppliers quote Thymine 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 Thymine

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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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