Uracil
[CAS# 66-22-8]

Identification

• Classification: Pharmaceutical intermediate >> Heterocyclic compound intermediate >> Pyrimidine compound >> Urinary (urea) pyrimidine
• Name: Uracil
• Synonyms: 2,4(1H,3H)-Pyrimidinedione; 2,4-Dihydroxypyrimidine
• Molecular Formula: C₄H₄N₂O₂
• Molecular Weight: 112.09
• CAS Registry Number: 66-22-8
• EC Number: 200-621-9
• SMILES: C1=CNC(=O)NC1=O

Properties

• Melting point: 335 °C
• Water solubility: SOLUBLE IN HOT WATER

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H302-H315-H319-H332-H335
• Safety Statements: P261-P280-P301+P312-P302+P352-P305+P351+P338

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Skin irritation	Skin Irrit.	2	H315
Specific target organ toxicity - single exposure	STOT SE	3	H335
Eye irritation	Eye Irrit.	2A	H319
Eye irritation	Eye Irrit.	2	H319

Discovery and Applications

Uracil was first discovered in 1900 by German chemist Robert Behrend. Its name is derived from the Greek word "ouron," meaning urine, because uracil was originally isolated from urine. This pyrimidine derivative was subsequently recognized as an essential component of ribonucleic acid (RNA), one of the two major nucleic acids essential for life. Together with adenine, guanine, and cytosine, uracil forms the basic building block of RNA, which carries genetic information from DNA and directs protein synthesis within cells.

Unlike DNA, which contains thymine, RNA utilizes uracil as the complementary base to adenine during transcription. This substitution enables RNA to act as a messenger, translating the genetic instructions encoded in DNA into proteins. This critical role makes uracil key in the complex mechanisms of gene expression and cellular function.

The importance of uracil is not limited to its fundamental role in genetics. It is a cornerstone of a variety of scientific disciplines and practical applications. The involvement of uracil in RNA makes it a key target for research in molecular biology and genetics. Research often focuses on understanding the structure, function, and regulation of RNA, aiming to shed light on diseases that stem from genetic abnormalities.

Uracil-based compounds have found applications in medicine, particularly in chemotherapy. Drugs such as fluorouracil (5-FU) and capecitabine are widely used in cancer treatments, interfering with RNA and DNA synthesis in rapidly dividing cancer cells, thereby inhibiting tumor growth.

In agriculture, uracil is integral to the development of genetically modified crops. RNA interference (RNAi) technology uses uracil-containing RNA molecules to silence specific genes in plants, providing targeted insect resistance and increasing crop yields.

In addition to biology, uracil derivatives are used in industrial processes such as dye production and chemical synthesis. Their diverse chemical properties contribute to a variety of applications in manufacturing and materials science.

References

1991. Role of uracil-DNA glycosylase in mutation avoidance by Streptococcus pneumoniae. Journal of Bacteriology, 173(1).
DOI: 10.1128/jb.173.1.283-290.1991

1979. Effect of 5-alkyl substitution of uracil on the thermal stability of poly[d(A-r5U)] copolymers. Nucleic Acids Research, 6(8).
DOI: 10.1093/nar/6.8.2839

1979. Determination of uracil and thymine and their nucleosides and nucleotides in picomole amounts by gas chromatography mass spectrometry selected ion monitoring. Biological Mass Spectrometry, 6(5).
DOI: 10.1002/bms.1200060505