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Safranin O

Athanor · official

C20H19ClN4 · 350.8 g/mol

IUPAC name: 3,7-dimethyl-10-phenylphenazin-10-ium-2,8-diamine chloride

Also called safranine, Gram counterstain, basic red 2

ReagentsRings
Open in Athanor
The structure of Safranin O
Drawn from its SMILES with RDKit
CorrosiveHarmful or irritantDangerCauses skin irritation · Causes serious eye damage · Causes serious eye irritation

Names and identifiers

IUPAC name
3,7-dimethyl-10-phenylphenazin-10-ium-2,8-diamine chloride
Synonyms
safranine, Gram counterstain, basic red 2
+ 39 more

BASIC RED 2, Safranin, Safranine O, Safranine T, Safranin T, Gossypimine, C.I. Basic Red 2, Safranine Zh, Safranine A, Safranine TH, Safranine, Safranine B, Safranine G, Safranine J, Safranine Y, Safranine GF, Safranine OK, Safranine TN, Safranine TS, Safranine YN, Tolusafranine, Hidaco safranine, Mitsui safranine, Brilliant safranine G, Calcozine Red Y, Leather Red HT, Mitsui safranine T, Safranine Superfine G, 2,8-Dimethylphenosafranine, Brilliant safranine BR, Brilliant safranine GR, Nippon kagaku safranine T, Nippon kagaku safranine GK, C.I. 50240, Cerven zasadita 2, Cerven zasadita 2 [Czech], CI 50240, Phenazinium, 3,7-diamino-2,8-dimethyl-5-phenyl-, chloride, CCRIS 1215

Molecular formula
C20H19ClN4
Empirical formula
C20H19ClN4
Molecular weight
350.8 g/mol
Exact mass
350.12982
CAS number
477-73-6
PubChem CID
2723800
Canonical SMILES
CC1=CC2=C(C=C1N)[N+](=C3C=C(C(=CC3=N2)C)N)C4=CC=CC=C4.[Cl-]
Isomeric SMILES
CC1=CC2=C(C=C1N)[N+](=C3C=C(C(=CC3=N2)C)N)C4=CC=CC=C4.[Cl-]
InChI
InChI=1S/C20H18N4.ClH/c1-12-8-17-19(10-15(12)21)24(14-6-4-3-5-7-14)20-11-16(22)13(2)9-18(20)23-17;/h3-11H,1-2H3,(H3,21,22);1H
InChIKey
OARRHUQTFTUEOS-UHFFFAOYSA-N
Molfile

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

Calculated

Heavy atoms
25
Rings
4
Aromatic rings
4
Fraction sp³ carbons (Fsp3)
0.1
H-bond donors
2
H-bond acceptors
3 computed here · PubChem 4
Rotatable bonds
1
TPSA (Ų)
68.8
Formal charge
0
Complexity
405 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

  • C68.47%
  • H5.46%
  • Cl10.10%
  • N15.97%

Isotope pattern

100%350.13023%351.13335%352.1277.6%353.130354.133

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)
-2.82 ESOL (Delaney 2004), log mol/L
Synthetic accessibility
2.9 SA score, 1 easy to 10 hard (Ertl and Schuffenhauer 2009)

Drug-likeness: Lipinski’s rule of five

  • Molecular weight ≤ 500: 350.85
  • log P ≤ 5 (Crippen): 0.45
  • H-bond donors ≤ 5: 2
  • 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

Danger

Most widely reported: 71 company reports to ECHA. Source [1].

  • Corrosive
  • Harmful or irritant
  • H315Causes skin irritation (16.9% of reports)
  • H318Causes serious eye damage (76.1% of reports)
  • H319Causes serious eye irritation (18.3% of reports)

Precautionary statements: P264, P264+P265, P280, P302+P352, P305+P351+P338, P305+P354+P338, P317, P321, P332+P317, P337+P317, P362+P364

View all classifications (2)
  • [1] European Chemicals Agency (ECHA)This chemical does not meet GHS hazard criteria for 2.8% (2 of 71) of reports.
  • [1] European Chemicals Agency (ECHA) · 71 reports · DangerH315, H318, H319

Safety data sheets on the supplier’s page: Alfa Chemistry, Sigma-Aldrich, Accela ChemBio Inc..

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. [1]European Chemicals Agency (ECHA) · ECHA legal notice: reuse with acknowledgement · via PubChem · retrieved 2026-10-14
  2. [2]SpectraBase · Linked only · via PubChem · retrieved 2026-10-14
  3. ·Calculated values: computed by Athanor with RDKit 2026.09 from the structure.
  4. ·Literature on PubChem

Data last updated 2026-10-14.