Isocytosine

Synonym(s):2-Amino-4-hydroxypyrimidine;2-Aminouracil

CAS NO.：108-53-2
Empirical Formula: C4H5N3O
Molecular Weight: 111.1
MDL number: MFCD00057557
EINECS: 203-592-0
SAFETY DATA SHEET (SDS)
Update Date: 2026-05-28 05:54:01

What is Isocytosine?

Description

Isocytosine (2-aminouracil) is a non-natural nucleobase and an isomer of one of the four main bases in DNA and RNA. It pairs in a “reversed Watson–Crick” manner with natural guanine or in a normal manner with non-natural isoguanine. In aqueous solution, it exists as two tautomers, the one shown and the other with a proton on the ring nitrogen opposite the carbonyl group.

Chemical properties

White to Off-White Solid

The Uses of Isocytosine

Isocytosine is a useful intermediate for chemical modifications of base and sugar moieties in natural nucleosides

The Uses of Isocytosine

Isocytosine (2-aminouracil) is an isomer of cytosine used in physical chemical studies involving metal complex binding, hydrogen-bonding, and tautomerism and proton transfer effects in nucleobases.

Definition

ChEBI: An aminopyrimidine in which the pyrimidine ring bears amino and hydroxy substituents at positions 2 and 4, respectively.

Properties of Isocytosine

Melting point:	275°C
Density	1.55±0.1 g/cm3(Predicted)
storage temp.	Keep in dark place,Inert atmosphere,Room temperature
solubility	DMSO (Slightly)
pka	9.59±0.40(Predicted)
form	Crystalline Powder
color	White to off-white
Water Solubility	Soluble in DMF, DMSO, hot water, and AcOH.
CAS DataBase Reference	108-53-2(CAS DataBase Reference)

Safety information for Isocytosine

Signal word	Warning
Pictogram(s)	Exclamation Mark Irritant GHS07
GHS Hazard Statements	H302:Acute toxicity,oral H319:Serious eye damage/eye irritation
Precautionary Statement Codes	P264:Wash hands thoroughly after handling. P264:Wash skin thouroughly after handling. P270:Do not eat, drink or smoke when using this product. P280:Wear protective gloves/protective clothing/eye protection/face protection. P301+P312:IF SWALLOWED: call a POISON CENTER or doctor/physician IF you feel unwell. P305+P351+P338:IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing. P337+P313:IF eye irritation persists: Get medical advice/attention.