A summary of the most common chemical descriptors (InChI Key and SMILES codes) for Uracil are summarized together with 3D and 2D structures and relevant physico-chemical properties.

What is the Uracil?

The molecule Uracil presents a molecular formula of C4H4N2O2 and its IUPAC name is 1H-pyrimidine-2,4-dione.

Uracil is one of the four nucleotide bases found in RNA, the molecule that carries the genetic information of an organism. It is a pyrimidine base, meaning it has a single-ring structure. In DNA, the pyrimidine base thymine belongs in its place..

Uracil is involved in the synthesis of RNA, which occurs through a process called transcription. During transcription, DNA is copied into RNA, and uracil is synthesized from the nucleotide base cytosine through the action of the enzyme cytidine deaminase..

Uracil has a number of important biological functions. It is a key component of RNA, which plays a central role in the synthesis of proteins. It is also involved in the regulation of gene expression and the control of various cellular processes..

Uracil is not typically available as a dietary supplement, but it can be obtained through the diet by consuming foods that are rich in nucleotide bases, such as meat, fish, dairy products, and eggs. However, the body has mechanisms in place to synthesize uracil, so it is not necessary to consume it through the diet..


From all the above, this molecule is an important nucleotide base that plays a key role in the synthesis of RNA and has a number of important biological functions. It is not typically available as a dietary supplement, but it can be obtained through the diet by consuming foods that are rich in nucleotide bases..

3D structure

Cartesian coordinates

Geometry of Uracil in x, y and z coordinates (Å units) to copy/paste elsewhere. Generated with Open Babel software.

2D drawing


Uracil ISAKRJDGNUQOIC-UHFFFAOYSA-N chemical compound 2D structure molecule svg


Molecule descriptors

IUPAC name1H-pyrimidine-2,4-dione
InChI codeInChI=1S/C4H4N2O2/c7-3-1-2-5-4(8)6-3/h1-2H,(H2,5,6,7,8)

Other names (synonyms)

IUPAC nomenclature provides a standardized method for naming chemical compounds. Although this system is widely used in chemistry, many chemical compounds have also other names commonly used in different contexts. These synonyms can come from a variety of sources and are used for a variety of purposes.

One common source of synonyms for chemical compounds is the common or trivial names, assigned on the basis of appearance, properties, or origin of the molecule.

Another source of synonyms are historical or obsolete names employed in the past, however replaced nowadays by more modern or standardized names.

In addition to common and historical names, chemical compounds may also have synonyms that are specific to a particular field or industry.

  • 1,2,3,4-tetrahydropyrimidine-2,4-dione
  • 144104-68-7
  • 1H-Pyrimidine-2,4-dione
  • 1H-pyrimidine-2,4-dione;Uracil
  • 1ui0
  • 2,3H)-Pyrimidinedione
  • 2,4(1H,3H)-Pyrimidinedione
  • 2,4(1H,3H)-Pyrimidinedione (9CI)
  • 2,4-(1h,3h)-pyrimidinedione
  • 2,4-?Dihydroxypyrimidine
  • 2,4-Dihydroxypyrimidine
  • 2,4-Dioxopyrimidine
  • 2,4-Dioxypyrimidine
  • 2,4-Pyrimidinediol
  • 2,4-Pyrimidinediol (9CI)
  • 2,4-Pyrimidinedione
  • 2,6-Dihydroxypyrimidine
  • 2,6-Dioxypyrimidin
  • 2-Hydroxy-4(1H)-pyrimidinone
  • 2-Hydroxy-4(3H)-pyrimidinone
  • 4(3H)-Pyrimidinone, 2-hydroxy- (9CI)
  • 4-Hydroxy-2(1H)-pyrimidinone
  • 4-Hydroxyuracil
  • 51953-14-1
  • 56HH86ZVCT
  • 66-22-8
  • 66255-05-8
  • 8h-uracil
  • A835376
  • AB00171810_03
  • AB00171810_04
  • AB00918623-05
  • AC-907/30002021
  • AI3-25470
  • AM83913
  • BB 0242167
  • BCP26546
  • BDBM50549809
  • BMS 205603-01
  • BMS-205603-01
  • C00106
  • CCG-213042
  • CCG-35866
  • CCRIS 3077
  • CID 5274267
  • CS-W020104
  • D00027
  • DB-030518
  • DB-103964
  • DB03419
  • DSSTox_CID_1424
  • DSSTox_GSID_21424
  • DSSTox_RID_76153
  • E2FC11E5-1887-46DF-B415-82313CE9B2BD
  • Epitope ID:120356
  • F1796-0008
  • FT-0609769
  • FT-0694063
  • FT-0695907
  • FT-0695908
  • FT-0773727
  • Fluorouracil Impurity C
  • Fluorouracil specified compound c
  • GTPL4560
  • HMS2234E19
  • HMS3264C13
  • HMS3373E18
  • HMS3652N05
  • HY-I0960
  • Hybar X
  • Lamivudine impurity e
  • Lamivudine impurity e rs
  • MFCD00006016
  • MLS001304993
  • NCGC00181030-01
  • NCGC00181030-02
  • NCGC00247663-01
  • NCGC00258576-01
  • NCI60_003718
  • NCIMech_000782
  • NSC 3970
  • NSC-29742
  • NSC-3970
  • NSC-759649
  • NSC29742
  • NSC3970
  • NSC759649
  • PS-5279
  • Pharmakon1600-01502345
  • Pirod
  • Pyrimidine-2,4(1H,3H)-dione (Uracil)
  • Pyrod
  • Q182990
  • RU 12709
  • SB55489
  • SB55884
  • SMR000752912
  • SQ 6201
  • SQ 7726
  • SQ 8493
  • SQ-6201
  • SQ-7726
  • SQ-8493
  • STK301734
  • STL124066
  • SW220239-1
  • SY008943
  • U0013
  • Ura
  • Uracil
  • Uracil (8CI)
  • Uracil (JAN/USAN)
  • Uracil,(S)
  • Uracyl
  • Urazil
  • Z56889474
  • bmse000187
  • bmse000940
  • hydroxypyrimidinone
  • pyrimidine-2,4(1H,3H)-dione
  • pyrimidine-2,4-diol
  • pyrimidine-2,4-dione
  • s4177
  • uracil

Reference codes for other databases

There exist several different chemical codes commonly used in orded to identify molecules:
  • ZINC895045
  • CAS-66-22-8
  • AKOS000119989
  • AKOS002303991
  • DTXSID4021424
  • CHEMBL566
  • CHEBI:17568
  • Tox21_112680
  • Tox21_201023
  • Tox21_112680_1
  • EINECS 200-621-9
  • SCHEMBL8235

Physico-Chemical properties

IUPAC name1H-pyrimidine-2,4-dione
Molecular formulaC4H4N2O2
Molecular weight112.09
Melting point (ºC)
Boiling point (ºC)
Density (g/cm3)
Molar refractivity27.7
Topological polar surface area65.7

LogP and topological polar surface area (TPSA) values were estimated using Open Babel software.

The n-octanol/water partition coeficient (Kow) data is applied in toxicology and drug research. Kow values are used, to guess the environmental fate of persistent organic pollutants. High partition coefficients values, tend to accumulate in the fatty tissue of organisms. Molecules with a log(Kow) (or LogP) greater than 5 are considered to bioaccumulate.

TPSA values are the sum of the surface area over all polar atoms or molecules, mainly oxygen and nitrogen, also including hydrogen atoms.

In medicinal chemistry, TPSA is used to assess the ability of a drug to permeabilise cells.

For molecules to penetrate the blood-brain barrier (and act on receptors in the central nervous system), TPSA values below 90 Å2 are required. Thus, molecules with a polar surface area greater than 140 Å2 tend to be poorly permeable to cell membranes.