Quinoxaline
Athanor · official
C8H6N2 · 130.15 g/mol
Also called benzopyrazine, 1,4-benzodiazine
WarningCauses skin irritation · Causes serious eye irritation · May cause respiratory irritationNames and identifiers
- IUPAC name
- quinoxaline
- Synonyms
- benzopyrazine, 1,4-benzodiazine, 1,4-Benzodiazine
+ 37 more
Benzoparadiazine, Benzopyrazine, Phenopiazine, Phenpiazine, Quinazine, 1,4-Diazanaphthalene, Benzo[a]pyrazine, 1,4-Naphthyridine, USAF EK-7094, Chinoxalin, Benzo(a)pyrazine, CCRIS 2947, DTXSID6049432, UNII-QM4AR6M6T8, QM4AR6M6T8, CHEBI:36616, QUINOXALINE [MI], EINECS 202-047-4, AI3-21308, DTXCID5029392, 1,4-Quinoxaline, RefChem:178342, 202-047-4, InChI=1/C8H6N2/c1-2-4-8-7(3-1)9-5-6-10-8/h1-6, XSCHRSMBECNVNS-UHFFFAOYSA-N, MFCD00006719, Quinoxaline, analytical standard, EN300-21366, doi:10.14272/XSCHRSMBECNVNS-UHFFFAOYSA-N.1, Z104495568, Quinoxalines, Quinoxaline, 99%, Quinoxaline (8CI,9CI), Epitope ID:547127, Quinoxaline, >=95.0%, SCHEMBL1973, SCHEMBL5315
- Molecular formula
- C8H6N2
- Empirical formula
- C4H3N
- Molecular weight
- 130.15 g/mol
- Exact mass
- 130.05310
- CAS number
- 91-19-0
- PubChem CID
- 7045
- Canonical SMILES
- C1=CC=C2C(=C1)N=CC=N2
- Isomeric SMILES
- C1=CC=C2C(=C1)N=CC=N2
- InChI
- InChI=1S/C8H6N2/c1-2-4-8-7(3-1)9-5-6-10-8/h1-6H
- InChIKey
- XSCHRSMBECNVNS-UHFFFAOYSA-N
- Molfile
Names, InChI and the identifiers from PubChem, retrieved 2026-10-14.
Calculated
- Heavy atoms
- 10
- Rings
- 2
- Aromatic rings
- 2
- Fraction sp³ carbons (Fsp3)
- 0
- H-bond donors
- 0
- H-bond acceptors
- 2
- Rotatable bonds
- 0
- TPSA (Ų)
- 25.8
- Formal charge
- 0
- XLogP3
- 1.3 PubChem
- Complexity
- 99 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
- C73.83%
- H4.65%
- N21.52%
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
- 1.63 Crippen (Wildman and Crippen 1999)
- log S (water solubility)
- -2.41 ESOL (Delaney 2004), log mol/L
- Synthetic accessibility
- 1.59 SA score, 1 easy to 10 hard (Ertl and Schuffenhauer 2009)
Drug-likeness: Lipinski’s rule of five
- Molecular weight ≤ 500: 130.15
- log P ≤ 5 (Crippen): 1.63
- 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
Warning
Most widely reported: 45 company reports to ECHA. Source [1].
- Harmful or irritant
- H315Causes skin irritation
- H319Causes serious eye irritation
- H335May cause respiratory irritation (97.8% 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
Safety data sheets on the supplier’s page: Life Chemicals, J&H Chemical Co.,ltd, Alfa Chemistry.
Always read the supplier’s safety data sheet before working with it.
Spectra
- NMRNMRShiftDB
- 1H NMRSpectraBase (Varian A-60D)
- 13C NMRSpectraBase
- 15N NMRSpectraBase
- GC-MSMassBank of North America (MoNA) (VARIAN MAT-44 · EI-B · positive) · MassBank of North America (MoNA) (HITACHI M-80B · EI-B · positive) · NIST Mass Spectrometry Data Center · NIST Mass Spectrometry Data Center · SpectraBase
- MS-MSHuman Metabolome Database (HMDB) (Positive) · Human Metabolome Database (HMDB) (Positive) · Human Metabolome Database (HMDB) (Positive) · Human Metabolome Database (HMDB) (Positive) · Human Metabolome Database (HMDB) (Positive) · Human Metabolome Database (HMDB) (Positive)
- LC-MSMassBank Europe (Q Exactive Plus Orbitrap Thermo Scientific · LC-ESI-QFT · POSITIVE) · MassBank of North America (MoNA) (Q Exactive Plus Orbitrap Thermo Scientific · LC-ESI-QFT · ESI)
- Other MSMassBank Europe (VARIAN MAT-44 · EI-B · POSITIVE) · MassBank Europe (HITACHI M-80B · EI-B · POSITIVE)
- FTIRSpectraBase (CAPILLARY CELL: MELT (LIQUID PHASE))
- ATR-IRSpectraBase (Bio-Rad FTS · ATR-Film (MeCl2) (DuraSamplIR II))
- Vapor Phase IRSpectraBase (DIGILAB FTS-14 · Vapor Phase)
- 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]MassBank of North America (MoNA) · CC BY 4.0 · via PubChem · retrieved 2026-10-14
- [5]NIST Mass Spectrometry Data Center · Linked only · via PubChem · retrieved 2026-10-14
- [6]Human Metabolome Database (HMDB) · Linked only · via PubChem · retrieved 2026-10-14
- [7]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.