IUPAC Name: 1-Hydroxypyrrole-2,5-dione 
Empirical Formula: C₄H₃NO₃
Molecular Weight: 113.0715
Canonical SMILES: C1=CC(=O)N(C1=O)O
InChI: InChI=1S/C4H3NO3/c6-3-1-2-4(7)5(3)8/h1-2,8H
InChIKey: BUXKULRFRATXSI-UHFFFAOYSA-N
XLogP3-AA: -1
H-Bond Donor: 1
H-Bond Acceptor: 3 
EINECS: 225-385-4 
Index of Refraction: 1.666
Molar Refractivity: 23.46 cm³
Molar Volume: 63 cm³
Surface Tension: 104.9 dyne/cm
Density: 1.793 g/cm³
Flash Point: 121.2 °C
Enthalpy of Vaporization: 59.83 kJ/mol
Boiling Point: 276.8 °C at 760 mmHg
Vapour Pressure: 0.000581 mmHg at 25 °C
Product Categories: Miscellaneous; Heterocyclic Compounds; Heterocycles; Active Esters/Additives; Active Esters/AdditivesSynthetic Reagents; Coupling; Peptide Synthesis
Melting Point of 1H-Pyrrole-2,5-dione,1-hydroxy- (CAS NO.4814-74-8): 130-133 °C (dec.)(lit.)

Hazard Codes: C
Risk Statements: 34-20/21/22 
R34:Causes burns. 
R20/21/22:Harmful by inhalation, in contact with skin and if swallowed.
Safety Statements: 26-36/37/39-45 
S26: In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. 
S36/37/39:Wear suitable protective clothing, gloves and eye/face protection. 
S45:In case of accident or if you feel unwell, seek medical advice immediately (show the label whenever possible.)
RIDADR: UN 3261 8/PG 3
WGK Germany: 3
F: 10-21
HazardClass: 8
PackingGroup of 1H-Pyrrole-2,5-dione,1-hydroxy- (CAS NO.4814-74-8): III

 1H-Pyrrole-2,5-dione,1-hydroxy- (CAS NO.4814-74-8), its Synonyms are 1-Hydroxy-1H-pyrrole-2,5-dione ; N-Hydroxymaleimide ; 1-Hydroxy-2,5-dihydro-1H-pyrrole-2,5-dione . It is yellow to brown crystalline powder.