Sudan III
Athanor · official
C22H16N4O · 352.4 g/mol
IUPAC name: 1-[(4-phenyldiazenylphenyl)diazenyl]naphthalen-2-ol
Also called solvent red 23, lipid stain, fat stain
DangerCauses skin irritation · Causes serious eye damageNames and identifiers
- IUPAC name
- 1-[(4-phenyldiazenylphenyl)diazenyl]naphthalen-2-ol
- Synonyms
- solvent red 23, lipid stain, fat stain
+ 38 more
Solvent red 23, C.I. Solvent Red 23, Toney Red, Fettponceau G, Cerasin Red, Fat Scarlet LB, Fettscharlach, Cerasinrot, Fettrot, Sudan Red III, Rouge cerasine, Stearix Scarlet, Pyronalrot B, Sudan P III, Fettscharlach LB, Organol Red BS, Soudan III, Cerotinscharlach R, Somalia Red III, Motirot 2R, Sudan Red BK, Fat Red R, Fat Red HRR, Sudan G III, Red ZH, Silotras Scarlet TB, Fat Soluble Red ZH, Schultz No. 31, Grasal Brilliant Red G, Grasan Brilliant Red G, Fat Red (bluish), C.I. 26100, D and C Red No. 17, Red No. 225, Tetrazobenzene-beta-naphthol, FD and C Red No. 17, D & C Red no. 17, Ponceau, insoluble, OLG
- Molecular formula
- C22H16N4O
- Empirical formula
- C22H16N4O
- Molecular weight
- 352.4 g/mol
- Exact mass
- 352.13241
- CAS number
- 85-86-9
- PubChem CID
- 62331
- Canonical SMILES
- C1=CC=C(C=C1)N=NC2=CC=C(C=C2)N=NC3=C(C=CC4=CC=CC=C43)O
- Isomeric SMILES
- C1=CC=C(C=C1)N=NC2=CC=C(C=C2)N=NC3=C(C=CC4=CC=CC=C43)O
- InChI
- InChI=1S/C22H16N4O/c27-21-15-10-16-6-4-5-9-20(16)22(21)26-25-19-13-11-18(12-14-19)24-23-17-7-2-1-3-8-17/h1-15,27H
- InChIKey
- FHNINJWBTRXEBC-UHFFFAOYSA-N
- Molfile
Names, InChI and the identifiers from PubChem, retrieved 2026-10-14.
Calculated
- Heavy atoms
- 27
- Rings
- 4
- Aromatic rings
- 4
- Fraction sp³ carbons (Fsp3)
- 0
- H-bond donors
- 1
- H-bond acceptors
- 5
- Rotatable bonds
- 4
- TPSA (Ų)
- 69.7
- Formal charge
- 0
- XLogP3
- 5.9 PubChem
- Complexity
- 508 PubChem
- Stereocenters
- None
- Double-bond geometry
- N12=N13: E · N20=N21: E
- Point group
- C1 of one 3D conformer with its hydrogens, by Athanor’s engine (as in the app)
Elemental analysis
- C74.98%
- H4.58%
- N15.90%
- O4.54%
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
- 7.38 Crippen (Wildman and Crippen 1999)
- log S (water solubility)
- -7.01 ESOL (Delaney 2004), log mol/L
- Synthetic accessibility
- 2.48 SA score, 1 easy to 10 hard (Ertl and Schuffenhauer 2009)
Drug-likeness: Lipinski’s rule of five
- Molecular weight ≤ 500: 352.4
- log P ≤ 5 (Crippen): 7.38
- H-bond donors ≤ 5: 1
- H-bond acceptors ≤ 10: 5
Breaks 1 of the 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: 225 company reports to ECHA. Source [1].
- Corrosive
- Harmful or irritant
- H315Causes skin irritation (21.3% of reports)
- H318Causes serious eye damage (16.4% of reports)
Precautionary statements: P264, P264+P265, P280, P302+P352, P305+P354+P338, P317, P321, P332+P317, P362+P364
View all classifications (3)
- [1] European Chemicals Agency (ECHA)This chemical does not meet GHS hazard criteria for 77.8% (175 of 225) of all reports.
- [1] European Chemicals Agency (ECHA) · 225 reports · DangerH315, H318
- [1] European Chemicals Agency (ECHA) · DangerH315, H317, H318, H335, H341, H412
Safety data sheets on the supplier’s page: Clearsynth, LGC Standards, Fluorochem.
Always read the supplier’s safety data sheet before working with it.
Spectra
- GC-MSNIST Mass Spectrometry Data Center · NIST Mass Spectrometry Data Center · NIST Mass Spectrometry Data Center
- LC-MSMassBank Europe (Bruker maXis Impact · LC-ESI-QTOF · POSITIVE) · MassBank Europe (Bruker maXis Impact · LC-ESI-QTOF · POSITIVE) · MassBank Europe (Bruker maXis Impact · LC-ESI-QTOF · POSITIVE) · MassBank Europe (Bruker maXis Impact · LC-ESI-QTOF · POSITIVE) · MassBank Europe (Bruker maXis Impact · LC-ESI-QTOF · POSITIVE) · MassBank Europe (Bruker maXis Impact · LC-ESI-QTOF · POSITIVE)
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]NIST Mass Spectrometry Data Center · Linked only · via PubChem · retrieved 2026-10-14
- [3]MassBank Europe · Linked only · via PubChem · retrieved 2026-10-14
- [4]MassBank of North America (MoNA) · CC BY 4.0 · 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.