Menadione

Athanor · official

C₁₁H₈O₂ · 172.18 g/mol

IUPAC name: 2-methylnaphthalene-1,4-dione

Also called vitamin K3, vitamin K, menaphthone, 2-methylnaphthoquinone

Vitamins

Open in Athanor

Drawn from its SMILES with RDKit

WarningHarmful if swallowed · Causes skin irritation · May cause an allergic skin reaction · Causes serious eye irritation · May cause respiratory irritation · Very toxic to aquatic life · Very toxic to aquatic life with long lasting effects

Names and identifiers

IUPAC name: 2-methylnaphthalene-1,4-dione
Synonyms: vitamin K3, vitamin K, menaphthone
+ 39 more
2-methylnaphthoquinone, Vitamin K3, 2-Methyl-1,4-naphthoquinone, 2-methylnaphthalene-1,4-dione, Kayquinone, Menaphthone, Thyloquinone, Kanone, Kappaxin, Kayklot, Klottone, Panosine, 2-Methyl-1,4-naphthalenedione, Kolklot, 2-Methylnaphthoquinone, Kareon, Koaxin, Kipca, Aquinone, Kaergona, Menadion, Menaphthon, Prokayvit, Aquakay, Synkay, Kativ-G, K-Thrombyl, Hemodal, Kappaxan, Mitenon, Mitenone, Karcon, Kaykot, Juva-K, K-Vitan, Vitamin K2(0), Vitamin K 3, Menaquinone 0, Vitamin K0
Molecular formula: C₁₁H₈O₂
Empirical formula: C₁₁H₈O₂
Molecular weight: 172.18 g/mol
Exact mass: 172.05243
CAS number: 58-27-5
PubChem CID: 4055
Canonical SMILES: CC1=CC(=O)C2=CC=CC=C2C1=O
Isomeric SMILES: CC1=CC(=O)C2=CC=CC=C2C1=O
InChI: InChI=1S/C11H8O2/c1-7-6-10(12)8-4-2-3-5-9(8)11(7)13/h2-6H,1H3
InChIKey: MJVAVZPDRWSRRC-UHFFFAOYSA-N
Molfile

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

Physical properties

Odor: Nearly odorless[1]
Solubility in water: Soluble in aromatic solvents[1]
4 values
From Hazardous Substances Data Bank (HSDB), the most authoritative source here.
Value As written Source
– Slightly soluble in ethanol, acetic acid, and ligroin. Soluble in ethyl ether, benzene, chloroform, and sulfuric acid. [1] Hazardous Substances Data Bank (HSDB)cites Lide, D.R., G.W.A. Milne (eds.). Handbook of Data on Organic Compounds. Volume I. 3rd ed. CRC Press, Inc. Boca Raton ,FL. 1994., p. V4 3534
–shown Soluble in aromatic solvents [1] Hazardous Substances Data Bank (HSDB)cites Ashford, R.D. Ashford's Dictionary of Industrial Chemicals. London, England: Wavelength Publications Ltd., 1994., p. 556
– SOL IN FATS [1] Hazardous Substances Data Bank (HSDB)cites Goodman, L.S., and A. Gilman. (eds.) The Pharmacological Basis of Therapeutics. 5th ed. New York: Macmillan Publishing Co., Inc., 1975., p. 1592
– For more Solubility (Complete) data for MENADIONE (6 total), please visit the HSDB record page. [1] Hazardous Substances Data Bank (HSDB)
log P: log Kow = 2.20 @ pH 7.4[1]

Value	As written	Source
–	Slightly soluble in ethanol, acetic acid, and ligroin. Soluble in ethyl ether, benzene, chloroform, and sulfuric acid.	[1] Hazardous Substances Data Bank (HSDB)cites Lide, D.R., G.W.A. Milne (eds.). Handbook of Data on Organic Compounds. Volume I. 3rd ed. CRC Press, Inc. Boca Raton ,FL. 1994., p. V4 3534
–shown	Soluble in aromatic solvents	[1] Hazardous Substances Data Bank (HSDB)cites Ashford, R.D. Ashford's Dictionary of Industrial Chemicals. London, England: Wavelength Publications Ltd., 1994., p. 556
–	SOL IN FATS	[1] Hazardous Substances Data Bank (HSDB)cites Goodman, L.S., and A. Gilman. (eds.) The Pharmacological Basis of Therapeutics. 5th ed. New York: Macmillan Publishing Co., Inc., 1975., p. 1592
–	For more Solubility (Complete) data for MENADIONE (6 total), please visit the HSDB record page.	[1] Hazardous Substances Data Bank (HSDB)

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: 13
Rings: 2
Aromatic rings: 1
Fraction sp³ carbons (Fsp3): 0.09
H-bond donors: 0
H-bond acceptors: 2
Rotatable bonds: 0
TPSA (Å²): 34.1
Formal charge: 0
XLogP3: 2.2 PubChem
Complexity: 288 PubChem
Stereocenters: None
Double-bond geometry: None specified
Point group: Cs of one 3D conformer with its hydrogens, by Athanor’s engine (as in the app)

Elemental analysis

C76.73%
H4.68%
O18.58%

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: 2.01 Crippen (Wildman and Crippen 1999)
log S (water solubility): -2.52 ESOL (Delaney 2004), log mol/L
Synthetic accessibility: 1.95 SA score, 1 easy to 10 hard (Ertl and Schuffenhauer 2009)

Drug-likeness: Lipinski’s rule of five

Molecular weight ≤ 500: 172.18
log P ≤ 5 (Crippen): 2.01
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: 190 company reports to ECHA. Source [2].

Harmful or irritant
Environmental hazard

H302Harmful if swallowed (97.4% of reports)
H315Causes skin irritation (95.3% of reports)
H317May cause an allergic skin reaction (63.7% of reports)
H319Causes serious eye irritation
H335May cause respiratory irritation (98.4% of reports)
H400Very toxic to aquatic life (70.5% of reports)
H410Very toxic to aquatic life with long lasting effects (64.7% of reports)

Precautionary statements: P261, P264, P264+P265, P270, P271, P272, P273, P280, P301+P317, P302+P352, P304+P340, P305+P351+P338, P319, P321, P330, P332+P317, P333+P317, P337+P317, P362+P364, P391, P403+P233, P405, P501

Safety data sheets on the supplier’s page: Yuhao Chemical, Finetech Industry Limited, Sigma-Aldrich.

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]European Chemicals Agency (ECHA) · ECHA legal notice: reuse with acknowledgement · via PubChem · retrieved 2026-10-14
[3]NMRShiftDB · Linked only · via PubChem · retrieved 2026-10-14
[4]Human Metabolome Database (HMDB) · 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.