Pyrimidine

Pyrimidine
Names
	Preferred IUPAC name Pyrimidine
	Systematic IUPAC name 1,3-Diazabenzene
	Other names 1,3-Diazine; m-Diazine
Identifiers
CAS Number	289-95-2 ;
3D model (JSmol)	Interactive image;
ChEBI	CHEBI:16898 ;
ChEMBL	ChEMBL15562 ;
ChemSpider	8903 ;
ECHA InfoCard	100.005.479
KEGG	C00396 ;
MeSH	pyrimidine
PubChem CID	9260;
UNII	K8CXK5Q32L ;
CompTox Dashboard (EPA)	DTXSID1051228 ;
	InChI InChI=1S/C4H4N2/c1-2-5-4-6-3-1/h1-4H Key: CZPWVGJYEJSRLH-UHFFFAOYSA-N ; InChI=1/C4H4N2/c1-2-5-4-6-3-1/h1-4H Key: CZPWVGJYEJSRLH-UHFFFAOYAT;
	SMILES n1cnccc1;
Properties
Chemical formula	C4H4N2
Molar mass	80.088 g mol−1
Density	1.016 g cm−3
Melting point	20 to 22 °C (68 to 72 °F; 293 to 295 K)
Boiling point	123 to 124 °C (253 to 255 °F; 396 to 397 K)
Solubility in water	Miscible (25°C)
Acidity (pKa)	1.10 (protonated pyrimidine)
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Pyrimidine (C₄H₄N₂; /pɪˈrɪ.mɪˌdiːn, paɪˈrɪ.mɪˌdiːn/) is an aromatic, heterocyclic, organic compound similar to pyridine (C₅H₅N).^[3] 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.^[4]^: 250 The other diazines are pyrazine (nitrogen atoms at the 1 and 4 positions) and pyridazine (nitrogen atoms at the 1 and 2 positions).

In nucleic acids, three types of nucleobases are pyrimidine derivatives: cytosine (C), thymine (T), and uracil (U).

^ "Front Matter". Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. 2014. p. 141. doi:10.1039/9781849733069-FP001. ISBN 978-0-85404-182-4.
^ Brown, H. C.; et al. (1955). Baude, E. A.; F. C., Nachod (eds.). Determination of Organic Structures by Physical Methods. New York, NY: Academic Press.
^ Gilchrist, Thomas Lonsdale (1997). Heterocyclic chemistry. New York: Longman. ISBN 978-0-582-27843-1.
^ Joule, John A.; Mills, Keith, eds. (2010). Heterocyclic Chemistry (5th ed.). Oxford: Wiley. ISBN 978-1-405-13300-5.