N-Hydroxysuccinimide
Athanor · official
C4H5NO3 · 115.09 g/mol
IUPAC name: 1-hydroxypyrrolidine-2,5-dione
Also called NHS, active ester, bioconjugation
WarningCauses skin irritation · Causes serious eye irritation · May cause respiratory irritationNames and identifiers
- IUPAC name
- 1-hydroxypyrrolidine-2,5-dione
- Synonyms
- NHS, active ester, bioconjugation
+ 37 more
1-hydroxypyrrolidine-2,5-dione, 1-Hydroxysuccinimide, 1-Hydroxy-2,5-pyrrolidinedione, Hydroxysuccinimide, 2,5-Pyrrolidinedione, 1-hydroxy-, Succinimide, N-hydroxy-, MJE3791M4T, NSC-74335, DTXSID7064102, RefChem:830145, DTXCID7042855, 228-001-3, HOSu, N-hydroxy succinimide, MFCD00005516, N-hydroxysuccinimide (HOSu), Tofacitinib Impurity 121, N-Hydroxy-2,5-pyrrolidinedione, N-hydroxysuccinimid, CCRIS 2604, N-hydroxy-succinimide, EINECS 228-001-3, NSC 74335, N-hydroxysuccinic acid imide, UNII-MJE3791M4T, 1-hydroxy-pyrrolidine-2,5-dione, N-hydroxysucinimide, N-hyroxysuccinimide, N-Hydroxysuccinimde, N-Hydroxylsuccinimide, n-hydroxysuccin imide, 1-Hydroxy-2,5-pyrrolidinedione; NHS, HOSu., 2, 1-hydroxy-, N-hy dr oxy succinimide, N-Hydroxysuccinimide NHS, n-hydroxysuccinimide (nhs)
- Molecular formula
- C4H5NO3
- Empirical formula
- C4H5NO3
- Molecular weight
- 115.09 g/mol
- Exact mass
- 115.02694
- CAS number
- 6066-82-6
- PubChem CID
- 80170
- Canonical SMILES
- C1CC(=O)N(C1=O)O
- Isomeric SMILES
- C1CC(=O)N(C1=O)O
- InChI
- InChI=1S/C4H5NO3/c6-3-1-2-4(7)5(3)8/h8H,1-2H2
- InChIKey
- NQTADLQHYWFPDB-UHFFFAOYSA-N
- Molfile
Names, InChI and the identifiers from PubChem, retrieved 2026-10-14.
Calculated
- Heavy atoms
- 8
- Rings
- 1
- Aromatic rings
- 0
- Fraction sp³ carbons (Fsp3)
- 0.5
- H-bond donors
- 1
- H-bond acceptors
- 3
- Rotatable bonds
- 0
- TPSA (Ų)
- 57.6
- Formal charge
- 0
- XLogP3
- -1.4 PubChem
- Complexity
- 126 PubChem
- Stereocenters
- None
- Double-bond geometry
- None specified
- Point group
- C1 of one 3D conformer with its hydrogens, by Athanor’s engine (as in the app)
Elemental analysis
- C41.75%
- H4.38%
- N12.17%
- O41.70%
Isotope pattern
Each peak is a nominal mass with its abundance-weighted exact mass, as a percentage of the tallest, from IUPAC natural isotope abundances.
Computed from the structure with RDKit 2026.09 when this page was built, beside PubChem's own computed values from its record; where the two differ, both are shown.
Predicted
- log P
- -0.48 Crippen (Wildman and Crippen 1999)
- log S (water solubility)
- -0.25 ESOL (Delaney 2004), log mol/L
- Synthetic accessibility
- 2.78 SA score, 1 easy to 10 hard (Ertl and Schuffenhauer 2009)
Drug-likeness: Lipinski’s rule of five
- Molecular weight ≤ 500: 115.09
- log P ≤ 5 (Crippen): -0.48
- H-bond donors ≤ 5: 1
- H-bond acceptors ≤ 10: 3
Passes all four rules.
¹³C NMR shifts, predicted
Predictions, not measurements; each names its method. A measured log P, where a source reports one, is under Physical properties.
Safety
Warning
Most widely reported: 182 company reports to ECHA. Source [1].
- Harmful or irritant
- H315Causes skin irritation (30.2% of reports)
- H319Causes serious eye irritation (29.1% of reports)
- H335May cause respiratory irritation (29.1% of reports)
Precautionary statements: P261, P264, P264+P265, P271, P280, P302+P352, P304+P340, P305+P351+P338, P319, P321, P332+P317, P337+P317, P362+P364, P403+P233, P405, P501
View all classifications (2)
- [1] European Chemicals Agency (ECHA)This chemical does not meet GHS hazard criteria for 69.8% (127 of 182) of all reports.
- [1] European Chemicals Agency (ECHA) · 182 reports · WarningH315, H319, H335
Safety data sheets on the supplier’s page: Glentham Life Sciences Ltd., BLD Pharm, MP Biomedicals.
Always read the supplier’s safety data sheet before working with it.
Spectra
- NMRNMRShiftDB
- 1H NMRSpectraBase (BRUKER AC-300)
- 13C NMRSpectraBase
- 15N NMRSpectraBase
- GC-MSNIST Mass Spectrometry Data Center · NIST Mass Spectrometry Data Center · NIST Mass Spectrometry Data Center · SpectraBase
- FTIRSpectraBase (Bio-Rad FTS · KBr0)
- ATR-IRSpectraBase (Bio-Rad FTS · ATR-Neat)
- RamanSpectraBase (FT-Raman)
Experimental spectra held by these sources; each link opens the source's own record.
Literature
Reading PubChem, OpenAlex and GSRS…
Bioactivity
Reading ChEMBL…
References
- [1]European Chemicals Agency (ECHA) · ECHA legal notice: reuse with acknowledgement · via PubChem · retrieved 2026-10-14
- [2]NMRShiftDB · Linked only · via PubChem · retrieved 2026-10-14
- [3]SpectraBase · Linked only · via PubChem · retrieved 2026-10-14
- [4]NIST Mass Spectrometry Data Center · Linked only · via PubChem · retrieved 2026-10-14
- ·Calculated values: computed by Athanor with RDKit 2026.09 from the structure.
- ·Literature on PubChem
Data last updated 2026-10-14.