Pyrimidone is the name given to either of two

heterocyclic compound A heterocyclic compound or ring structure is a cyclic compound that has atoms of at least two different elements as members of its ring(s). Heterocyclic chemistry is the branch of organic chemistry dealing with the synthesis, properties, and ...

s with the formula C₄H₄N₂O: 2-pyrimidone and 4-pyrimidone. The compounds can also be called ''2-hydroxypyrimidine'' or ''4-hydroxypyrimidine'' respectively, based on a substituted

pyrimidine Pyrimidine (; ) is an aromatic, heterocyclic, organic compound similar to pyridine (). One of the three diazines (six-membered heterocyclics with two nitrogen atoms in the ring), it has nitrogen atoms at positions 1 and 3 in the ring. The other ...

, or 1,3-

diazine In organic chemistry, diazines are a group of organic compounds having the molecular formula . Each contains a benzene ring in which two of the C-H fragments have been replaced by isolobal nitrogen. There are three structural isomers: * pyridaz ...

, ring.

Derivatives

Derivatives of pyrimidone are the basis of many other biological molecules, including: *

Nucleobases Nucleobases, also known as ''nitrogenous bases'' or often simply ''bases'', are nitrogen-containing biological compounds that form nucleosides, which, in turn, are components of nucleotides, with all of these monomers constituting the basic b ...

, such as

cytosine Cytosine () ( symbol C or Cyt) is one of the four nucleobases found in DNA and RNA, along with adenine, guanine, and thymine (uracil in RNA). It is a pyrimidine derivative, with a heterocyclic aromatic ring and two substituents attached (an am ...

Barbiturates Barbiturates are a class of depressant drugs that are chemically derived from barbituric acid. They are effective when used medically as anxiolytics, hypnotics, and anticonvulsants, but have physical and psychological addiction potential as ...

, such as

metharbital Metharbital was patented in 1905 by Emil Fischer working for Merck. It was marketed as Gemonil by Abbott Laboratories. It is a barbiturate anticonvulsant, used in the treatment of epilepsy. It has similar properties to phenobarbital Phenobar ...

File:Cytosine chemical structure.png,

Cytosine Cytosine () ( symbol C or Cyt) is one of the four nucleobases found in DNA and RNA, along with adenine, guanine, and thymine (uracil in RNA). It is a pyrimidine derivative, with a heterocyclic aromatic ring and two substituents attached (an am ...

File:Metharbital.png,

Metharbital Metharbital was patented in 1905 by Emil Fischer working for Merck. It was marketed as Gemonil by Abbott Laboratories. It is a barbiturate anticonvulsant, used in the treatment of epilepsy. It has similar properties to phenobarbital Phenobar ...

*Antiulcer drugs including temelastine, icotidine, donetidine, and

lupitidine Lupitidine (INN; lupitidine hydrochloride (USAN); development code SKF-93479) is a long-acting H2 receptor antagonist developed by Smith, Kline & French and described as an antiulcerogenic that was never marketed. It was shown to inhibit noctur ...

. {{Heterocyclic-stub