N-Bromosuccinimide

Athanor · official

C₄H₄BrNO₂ · 177.98 g/mol

IUPAC name: 1-bromopyrrolidine-2,5-dione

Also called NBS, bromination

Reagents Rings

Open in Athanor

Drawn from its SMILES with RDKit

DangerMay intensify fire; oxidizer · May be corrosive to metals · Harmful if swallowed · Causes severe skin burns and eye damage · Causes skin irritation · May cause an allergic skin reaction · Causes serious eye irritation · May cause respiratory irritation · Suspected of causing genetic defects · Very toxic to aquatic life

Names and identifiers

IUPAC name: 1-bromopyrrolidine-2,5-dione
Synonyms: NBS, bromination, n-bromobutanimide
+ 36 more
RefChem:6049, 1-Bromopyrrolidine-2,5-dione, Succinbromimide, 2,5-Pyrrolidinedione, 1-bromo-, Succinbromide, 1-Bromo-2,5-pyrrolidinedione, Succinibromimide, N-Bromosuccimide, Succinimide, N-bromo-, N-Bromsuccinimide, N-bromo-succinimide, MFCD00005510, NSC 16, Succinobromimide, 1-Bromo-2,5-pyrrolidine-dione, Letrozole Impurity 13, K8G1F2UCJF, 1-Bromodihydro-1H-pyrrole-2,5-dione, 1-bromoazolidine-2,5-dione, NSC-16, n-bromo succinimide, CCRIS 2899, EINECS 204-877-2, UNII-K8G1F2UCJF, AI3-16619, bromo-succinimide, N-Bromsuccinimid, N-bromosuccinimid, N-bromosuccmimide, 1-Bromo-2,5-pyrrolidinedione; Bromosuccinimide; NBS; NSC 16; Succinbromimide;, n-brom-succinimide, N-bromo succinimid, N-bromosuccinirnide, N-brornosuccinimide, JV-bromosuccinimide, N -bromosuccinimide
Molecular formula: C₄H₄BrNO₂
Empirical formula: C₄H₄BrNO₂
Molecular weight: 177.98 g/mol
Exact mass: 176.94254
CAS number: 128-08-5
PubChem CID: 67184
Canonical SMILES: C1CC(=O)N(C1=O)Br
Isomeric SMILES: C1CC(=O)N(C1=O)Br
InChI: InChI=1S/C4H4BrNO2/c5-6-3(7)1-2-4(6)8/h1-2H2
InChIKey: PCLIMKBDDGJMGD-UHFFFAOYSA-N
Molfile

Names, InChI and the identifiers from PubChem, retrieved 2026-10-14.

Physical properties

TemperaturePressureDensity

Appearance: Solid at 20 °C and 1031 hPa; powder[1]
Boiling point: 338.9 °C at 101.325 kPa[1]
Density: 2.098 @25 °C[2]
Vapor pressure: VP: 0.001 Pa at 25 °C[1]

Each value as its source reports it, with the source's number after it (listed under References). Where several sources report a property, the row shows the value most of them agree on, the rule the app uses; open the values to see every one.

Calculated

Heavy atoms: 8
Rings: 1
Aromatic rings: 0
Fraction sp³ carbons (Fsp3): 0.5
H-bond donors: 0
H-bond acceptors: 2
Rotatable bonds: 0
TPSA (Å²): 37.4
Formal charge: 0
XLogP3: -0.1 PubChem
Complexity: 129 PubChem
Stereocenters: None
Double-bond geometry: None specified
Point group: C2v of one 3D conformer with its hydrogens, by Athanor’s engine (as in the app)

Elemental analysis

C26.99%
H2.27%
Br44.89%
N7.87%
O17.98%

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: 0.45 Crippen (Wildman and Crippen 1999)
log S (water solubility): -1.22 ESOL (Delaney 2004), log mol/L
Synthetic accessibility: 3.23 SA score, 1 easy to 10 hard (Ertl and Schuffenhauer 2009)

Drug-likeness: Lipinski’s rule of five

Molecular weight ≤ 500: 177.99
log P ≤ 5 (Crippen): 0.45
H-bond donors ≤ 5: 0
H-bond acceptors ≤ 10: 2

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

Danger

Most widely reported: 199 company reports to ECHA. Source [3].

Oxidizer
Corrosive
Harmful or irritant
Health hazard
Environmental hazard

H272May intensify fire; oxidizer (38.7% of reports)
H290May be corrosive to metals (38.7% of reports)
H302Harmful if swallowed (55.8% of reports)
H314Causes severe skin burns and eye damage (35.2% of reports)
H315Causes skin irritation (46.2% of reports)
H317May cause an allergic skin reaction (21.6% of reports)
H319Causes serious eye irritation (65.3% of reports)
H335May cause respiratory irritation (26.6% of reports)
H341Suspected of causing genetic defects (15.1% of reports)
H400Very toxic to aquatic life (43.2% of reports)

Precautionary statements: P203, P210, P220, P234, P260, P261, P264, P264+P265, P270, P271, P272, P273, P280, P301+P317, P301+P330+P331, P302+P352, P302+P361+P354, P304+P340, P305+P351+P338, P305+P354+P338, P316, P318, P319, P321, P330, P332+P317, P333+P317, P337+P317, P362+P364, P363, P370+P378, P390, P391, P403+P233, P405, P406, P501

View all classifications (2)

[3] European Chemicals Agency (ECHA) · 199 reports · DangerH272, H290, H302, H314, H315, H317, H319, H335, H341, H400
[1] Hazardous Substances Data Bank (HSDB) · DangerH302, H314, H318

Storage

Keep container tightly closed in a dry and well-ventilated place. Recommended storage temperature: 2 - 8 °C. Light sensitive. Moisture sensitive. Store under inert gas.[1]

Incompatibilities

Violent reaction with dibenzoyl peroxide + 4-toluic acid.[1]
Explosive reaction with propiononitrile after heating to 105 °C for 24 hr.[1]
Reacts explosively with aniline, diallyl sulfide, and hydrazine hydrate.[1]
Incompatible materials: Strong oxidizing agents, Strong acids, Strong bases, Iron and iron salts.[1]

Safety data sheets on the supplier’s page: Angene Chemical, Clinivex, Combi-Blocks.

Always read the supplier’s safety data sheet before working with it.

Spectra

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]Hazardous Substances Data Bank (HSDB) · Public domain (US NLM) · via PubChem · retrieved 2026-10-14
[2]PAC Chemical Database, U.S. Department of Energy · Public domain (US DOE) · via PubChem · retrieved 2026-10-14
[3]European Chemicals Agency (ECHA) · ECHA legal notice: reuse with acknowledgement · via PubChem · retrieved 2026-10-14
[4]NMRShiftDB · Linked only · via PubChem · retrieved 2026-10-14
[5]SpectraBase · Linked only · via PubChem · retrieved 2026-10-14
[6]MassBank of North America (MoNA) · CC BY 4.0 · via PubChem · retrieved 2026-10-14
[7]NIST Mass Spectrometry Data Center · Linked only · via PubChem · retrieved 2026-10-14
[8]MassBank Europe · 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.