Title: Pyrimidine
CAS Registry Number: 289-95-2
Additional Names: 1,3-Diazine; metadiazine; miazine
Molecular Formula: C4H4N2
Molecular Weight: 80.09
Percent Composition: C 59.99%, H 5.03%, N 34.98%
Literature References: Prepd by reducing 2,4,6-trichloropyrimidine with zinc dust: Gabriel, Ber. 33, 3666 (1900); by reducing tetrachloropyrimidine: Emery, ibid. 34, 4180 (1901); by reducing 2,4-dichloropyrimidine with magnesium oxide and palladium-charcoal: Wittaker, J. Chem. Soc. 1953, 1646.
Properties: Liquid or cryst mass; penetrating odor. mp 20-22°. bp762 123-124°. uv max (water): 240 nm (e 2400). Soluble in water, alcohol, ether.
Melting point: mp 20-22°
Boiling point: bp762 123-124°
Absorption maximum: uv max (water): 240 nm (e 2400)
Derivative Type: Methiodide
Molecular Formula: C4H4N2.CH3I
Molecular Weight: 222.03
Percent Composition: C 27.05%, H 3.18%, N 12.62%, I 57.16%
Properties: Yellow plates from ethanol, mp 136-137°.
Melting point: mp 136-137°
Pyriminil Pyrimithate Pyrinoline Pyriproxyfen Pyrisuccideanol

Pyrimidine 2D aromatic full.svg Pyrimidine 2D numbers.svg
Pyrimidine molecule Pyrimidine molecule
CAS number 289-95-2 YesY
PubChem 9260
ChemSpider 8903 YesY
KEGG C00396 YesY
MeSH pyrimidine
ChEBI CHEBI:16898 YesY
Jmol-3D images Image 1
Molecular 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
Acidity (pKa) 1.10[1] (protonated pyrimidine)
 YesY (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Pyrimidine is an aromatic heterocyclic organic compound similar to pyridine.[2] One of the three diazines (six-membered heterocyclics with two nitrogen atoms in the ring), it has the nitrogens at positions 1 and 3 in the ring.[3] The other diazines are pyrazine (nitrogens 1 and 4) and pyridazine (nitrogens 1 and 2). In nucleic acids, three types of nucleobases are pyrimidine derivatives: cytosine (C), thymine (T), and uracil (U).