Thymine

Description

Thymine · CAS 65-71-4 · C5H6N2O2. UNII QR26YLT7LT. Melting Point: 316; Melting Point: 320 °C; Solubility: 3820.

Identification

CAS Registry Number	65-71-4
PubChem CID	1135
Molecular formula	C5H6N2O2
IUPAC name	5-methyl-1H-pyrimidine-2,4-dione
UNII (FDA)	QR26YLT7LT

Computed Descriptors

Molecular Weight	126.11
XLogP3	-0.6
Hydrogen Bond Donor Count	2
Hydrogen Bond Acceptor Count	2
Rotatable Bond Count	0
Exact Mass	126.042927438
Monoisotopic Mass	126.042927438
Topological Polar Surface Area	58.2
Heavy Atom Count	9
Formal Charge	0

Physical & Chemical Properties

Melting Point	316
Melting Point	320 °C
Solubility	3820
Solubility	3.82 mg/mL
Vapor Pressure	0.00000133 [mmHg]
LogP	-0.62
LogP	-0.57
Ionization Efficiency	1.16
Ionization Efficiency	2.7
Ionization Efficiency	MeCN (80%)

Physical description & handling notes

• Solid; [Merck Index] White crystalline powder; [Alfa Aesar MSDS]
• Solid
• Positive
• Agilent XCT
• Electrospray ionization
• formic acid (5.3nM)

Regulatory Status

GHS notification summary	57.1% (4 / 7)

GHS Hazard Classification

GHS notification summary	57.1% (4 / 7)
Reported hazard statements	H319 (42.9%)

Documented Uses

• Component of nucleic acids; Used in biochemical research; [Merck Index]
• 2,4(1H,3H)-Pyrimidinedione, 5-methyl-: ACTIVE
• Beta Ureidopropionase Deficiency
• MNGIE (Mitochondrial Neurogastrointestinal Encephalopathy)
• UMP Synthase Deficiency (Orotic Aciduria)

Synonyms

thymine; 65-71-4; 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; DTXSID4052342; QR26YLT7LT; NSC14705; CHEBI:17821; NSC-14705

Frequently Asked Questions

What are the CAS number and molecular formula of Thymine?

CAS 65-71-4; molecular formula C5H6N2O2; molecular weight — g/mol.

What other names is Thymine known by?

thymine, 65-71-4, 5-methyluracil, 2,4-Dihydroxy-5-methylpyrimidine, Thymin, Thymine anhydrate.

Is Thymine classified as hazardous?

57.1% of GHS notifications report no hazard classification (4 of 7).

What are the key physical properties of Thymine?

Melting Point: 316; Melting Point: 320 °C; Solubility: 3820; Solubility: 3.82 mg/mL.

Facts on this page are taken from PubChem (US National Library of Medicine) and Wikidata. Grade-specific data — assay, moisture, particle size, packaging, shelf life — is issued per batch on the COA and is not published here.