2-Imidazolidinone

2-Imidazolidinone

Names
IUPAC name Imidazolidin-2-one
Other names Ethyleneurea 2-imidazolidone imidazolidin-2-one 1,3-ethyleneurea
Identifiers
CAS Number	120-93-4
3D model (JSmol)	Interactive image
ECHA InfoCard	100.004.034
PubChem CID	8453
CompTox Dashboard (EPA)	DTXSID0020602
InChI InChI=1S/C3H6N2O/c6-3-4-1-2-5-3/h1-2H2,(H2,4,5,6) Key: YAMHXTCMCPHKLN-UHFFFAOYSA-N
SMILES O=C1NCCN1
Properties
Chemical formula	C3H6N2O
Molar mass	86.094 g·mol−1
Appearance	White to off-white crystalline solid [1]
Density	1.15 g/cm3 [2]
Melting point	129–132 °C [3] [4]
Solubility in water	Soluble in water and methanol [4]
Hazards [5]
Occupational safety and health (OHS/OSH):
Main hazards	Irritant
GHS labelling: [6]
Pictograms
Signal word	Warning
Hazard statements	H315, H319, H335
Precautionary statements	P261, P264, P280, P302+P352, P305+P351+P338
Safety data sheet (SDS)	Sigma-Aldrich SDS
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

2-Imidazolidinone (imidazolidin-2-one) is a cyclic urea derivative. It is used as an intermediate in organic synthesis and as a building block for substituted imidazolidinones. ^[3]

Uses

2-Imidazolidinone is principally used as a formaldehyde scavenger in amino-resin systems and textile finishes. It reacts with free formaldehyde and with pendant N-methylol groups to form stable adducts, lowering free formaldehyde content and emissions. Applications include incorporation as an internal additive in urea-formaldehyde adhesives or as a post-treatment in textile finishing baths and on wood-based panels. Reported usage levels vary by application, commonly around 5–10% by weight relative to resin solids for internal scavenging, and 10–40% in commercial aqueous scavenger concentrates for surface or post-treatment applications. Careful optimization of resin formulation and curing is necessary to avoid adverse effects on bonding strength and cure behavior. ^{[7] [8] [9]}

Preparation

2-Imidazolidinone can be obtained by the direct condensation of ethylenediamine with urea or dimethyl carbonate: ^[10]

C₂H₄(NH₂)₂ + CO(NH₂)₂ → C₃H₆N₂O + 2 NH₃

H₂N–CH₂–CH₂–NH₂ + (MeO)₂CO → C₃H₆N₂O + 2 MeOH

It can also be obtained by the direct condensation of ethylene glycol and urea: ^{[11] [12] [13]}

CO(NH₂)₂ + HO–CH₂–CH₂–OH → C₃H₆N₂O + 2 H₂O

References

1. PubChem: 2-Imidazolidinone. https://pubchem.ncbi.nlm.nih.gov/compound/2-Imidazolidinone
2. Chemical data: Chemsrc / ChemicalBook listings. https://www.chemsrc.com/en/cas/120-93-4_243754.html
3. PubChem: melting point listing. https://pubchem.ncbi.nlm.nih.gov/compound/2-Imidazolidinone
4. TCI Chemicals product page. https://www.tcichemicals.com/CH/en/p/I0005
5. Sigma-Aldrich / supplier SDS listings for 2-imidazolidinone.
6. Sigma-Aldrich SDS; Merck Millipore SDS.
7. CN1739821A - Ethylene urea amino derivative formaldehyde scavenger. https://patents.google.com/patent/CN1739821A/en
8. WO2012029787 - Formaldehyde scavenger; WIPO. https://patentscope.wipo.int
9. Wang X., 'The Removal of Formaldehyde from Urea Adhesives', Polymers 2024.
10. Patent / process literature for DMC route.
11. US2526757A - Preparation of ethyleneurea. https://patents.google.com/patent/US2526757A/en
12. US2416046A - Process for the preparation of ethyleneurea. https://patents.google.com/patent/US2416046A/en
13. Schweitzer, C.E., J. Org. Chem. 1950.