Isocytosine

Isocytosine

IUPAC name 2-Amino-3H-pyrimidin-4-one
Other names 2-Aminouracil
Identifiers
CAS number	108-53-2
PubChem	66950
ChemSpider	60309^Y
ChEBI	CHEBI:55502^Y
ChEMBL	CHEMBL56260^Y
Jmol-3D images	Image 1
SMILES O=C1/C=C\N=C(\N)N1
InChI InChI=1S/C4H5N3O/c5-4-6-2-1-3(8)7-4/h1-2H,(H3,5,6,7,8)^Y Key: XQCZBXHVTFVIFE-UHFFFAOYSA-N^Y InChI=1/C4H5N3O/c5-4-6-2-1-3(8)7-4/h1-2H,(H3,5,6,7,8) Key: XQCZBXHVTFVIFE-UHFFFAOYAD
Properties
Molecular formula	C₄H₅N₃O
Molar mass	111.102
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Isocytosine or 2-aminouracil is a pyrimidine base that is an isomer of cytosine. It is used in combination with isoguanine in studies of unnatural nucleic acid analogues of the normal base pairs in DNA.