Coumarin
Athanor · official
C9H6O2 · 146.14 g/mol
IUPAC name: chromen-2-one
Also called 2H-chromen-2-one, benzopyrone, tonka bean camphor, 1,2-benzopyrone
DangerToxic if swallowed · Harmful if swallowed · May cause an allergic skin reactionNames and identifiers
- IUPAC name
- chromen-2-one
- Synonyms
- 2H-chromen-2-one, benzopyrone, tonka bean camphor
+ 39 more
1,2-benzopyrone, 2H-Chromen-2-one, 2H-1-Benzopyran-2-one, cumarin, 1,2-Benzopyrone, chromen-2-one, Tonka bean camphor, Rattex, Coumarinic anhydride, Coumarine, cis-o-Coumarinic acid lactone, Coumarinic lactone, o-Hydroxycinnamic acid lactone, Benzo-alpha-pyrone, 5,6-Benzo-2-pyrone, o-Hydroxycinnamic lactone, 2-Oxo-1,2-benzopyran, Kumarin, 2H-Benzo(b)pyran-2-one, 2H-1-Benzopyran, 2-oxo-, 5,6-Benzo-alpha-pyrone, Benzo-a-pyrone, o-Coumaric acid lactone, o-Hydroxyzimtsaure-lacton, Coumarinum, DTXSID7020348, cis-o-Coumaric acid anhydride, 2H-Benzo[b]pyran-2-one, 2-Propenoic acid, 3-(2-hydroxyphenyl)-, delta-lactone, 2-oxo-2H-1-benzopyran, Cinnamic acid, o-hydroxy-, delta-lactone, NSC-8774, A4VZ22K1WT, Nci-c07103, Coumarin (prohibited), CHEBI:28794, NSC8774, o-hydroxycinnamic acid delta-lactone, DTXCID50348
- Molecular formula
- C9H6O2
- Empirical formula
- C9H6O2
- Molecular weight
- 146.14 g/mol
- Exact mass
- 146.03678
- CAS number
- 91-64-5
- PubChem CID
- 323
- Canonical SMILES
- C1=CC=C2C(=C1)C=CC(=O)O2
- Isomeric SMILES
- C1=CC=C2C(=C1)C=CC(=O)O2
- InChI
- InChI=1S/C9H6O2/c10-9-6-5-7-3-1-2-4-8(7)11-9/h1-6H
- InChIKey
- ZYGHJZDHTFUPRJ-UHFFFAOYSA-N
- Molfile
Names, InChI and the identifiers from PubChem, retrieved 2026-10-14.
Physical properties
TemperaturePressureDensity
- Appearance
- White crystals[4]
5 values
From Hazardous Substances Data Bank (HSDB), the most authoritative source here.
Value As written Source – Coumarin appears as colorless crystals, flakes or colorless to white powder with a pleasant fragrant vanilla odor and a bitter aromatic burning taste. (NTP, 1992) [1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina. – Other Solid; Dry Powder; CBI; Large Crystals; Liquid; Other Solid; Liquid [2] EPA Chemical Data Reporting (CDR) – COLOURLESS FLAKES WITH CHARACTERISTIC ODOUR. [3] ILO-WHO International Chemical Safety Cards (ICSCs) – Colorless, crystals, flakes, or powder [4] Hazardous Substances Data Bank (HSDB)cites Lewis, R.J., Sr (Ed.). Hawley's Condensed Chemical Dictionary. 13th ed. New York, NY: John Wiley & Sons, Inc. 1997., p. 307 –shown White crystals [4] Hazardous Substances Data Bank (HSDB)cites Ashford, R.D. Ashford's Dictionary of Industrial Chemicals. London, England: Wavelength Publications Ltd., 1994., p. 238 - Odor
- Hay-like bittersweet odor[4]
- Melting point
- 68 to 70 °C (154 to 158 °F, NTP 1992)[1]
2 values
2 of 2 sources agree on it (most common value).
Value As written Source 68 to 70 °Cshown 154 to 158 °F (NTP, 1992) [1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina. 68 to 70 °C 68-70 °C [3] ILO-WHO International Chemical Safety Cards (ICSCs) - Boiling point
- 297-299 °C[3]
2 values
2 of 2 sources agree on it (most common value).
Value As written Source 298 °C 568 °F at 760 mmHg (NTP, 1992) [1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina. 297 to 299 °Cshown 297-299 °C [3] ILO-WHO International Chemical Safety Cards (ICSCs) - Density
- 0.935 @25 °C[5]
3 values
3 of 3 sources agree on it (most common value).
Value As written Source – 0.935 at 68 °F (NTP, 1992) - Less dense than water [1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina. – 0.94 g/cm³ [3] ILO-WHO International Chemical Safety Cards (ICSCs) –shown 0.935 @25 °C [5] PAC Chemical Database, U.S. Department of Energy - Solubility in water
- Solubility in water: poor[3]
5 values
From ILO-WHO International Chemical Safety Cards (ICSCs), the most authoritative source here.
Value As written Source – less than 0.1 mg/mL at 63.5 °F (NTP, 1992) [1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina. – Soluble in aqueous alkali, oxygenated and chlorinated solvents [4] Hazardous Substances Data Bank (HSDB)cites Ashford, R.D. Ashford's Dictionary of Industrial Chemicals. London, England: Wavelength Publications Ltd., 1994., p. 238 – In chloroform 49.4 g/100 g @ 25 °C; in pyridine 87.7 g/100 g @ 20-25 °C [4] Hazardous Substances Data Bank (HSDB)cites Kirk-Othmer Encyclopedia of Chemical Technology. 4th ed. Volumes 1: New York, NY. John Wiley and Sons, 1991-Present., p. V7 (1993) 648 – In water, 1,900 mg/l @ 20 °C [4] Hazardous Substances Data Bank (HSDB)cites Yalkowsky SH, Dannenfelser RM; The AQUASOL dATAbASE of Aqueous Solubility. Ver 5. Tucson, AZ: Univ AZ, College of Pharmacy (1992) –shown Solubility in water: poor [3] ILO-WHO International Chemical Safety Cards (ICSCs) - log P
- 1.39[3]
2 values
2 of 2 sources agree on it (most common value).
Value As written Source – log Kow = 1.39 [4] Hazardous Substances Data Bank (HSDB)cites Hansch, C., Leo, A., D. Hoekman. Exploring QSAR - Hydrophobic, Electronic, and Steric Constants. Washington, DC: American Chemical Society., 1995., p. 51 –shown 1.39 [3] ILO-WHO International Chemical Safety Cards (ICSCs) - Vapor pressure
- Vapor pressure, kPa at 106 °C: 0.13[3]
6 values
3 of 3 sources agree on it (most common value).
Value As written Source 0.01 mmHg 0.01 mmHg at 117 °F [1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina. 1 mmHg 1 mmHg at 223 °F (NTP, 1992) [1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina. 1 mmHg VP: 1 mm Hg @ 106.0 °C [4] Hazardous Substances Data Bank (HSDB)cites Verschueren, K. Handbook of Environmental Data on Organic Chemicals. Volumes 1-2. 4th ed. John Wiley & Sons. New York, NY. 2001, p. V1 588 40 mmHg 40 mm Hg @ 189 °C [4] Hazardous Substances Data Bank (HSDB)cites Verschueren, K. Handbook of Environmental Data on Organic Chemicals. Volumes 1-2. 4th ed. John Wiley & Sons. New York, NY. 2001, p. V1 588 0.00098 mmHg 9.8X10-4 mm Hg @ 25 °C, extrapolated [4] Hazardous Substances Data Bank (HSDB)cites Perry RH, Green D; Perry's Chemical Handbook. Physical and Chemical data. NY, NY: McGraw-Hill 6th ed (1984) 0.975 mmHgshown Vapor pressure, kPa at 106 °C: 0.13 [3] ILO-WHO International Chemical Safety Cards (ICSCs) - Flash point
- 150 °C[3]
2 values
2 of 2 sources agree on it (most common value).
Value As written Source 151 °C 304 °F (NTP, 1992) [1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina. 150 °Cshown 150 °C [3] ILO-WHO International Chemical Safety Cards (ICSCs)
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
- 11
- Rings
- 2
- Aromatic rings
- 2
- Fraction sp³ carbons (Fsp3)
- 0
- H-bond donors
- 0
- H-bond acceptors
- 2
- Rotatable bonds
- 0
- TPSA (Ų)
- 30.2 computed here · PubChem 26.3
- Formal charge
- 0
- XLogP3
- 1.4 PubChem
- Complexity
- 196 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
- C73.97%
- H4.14%
- O21.89%
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
- 1.79 Crippen (Wildman and Crippen 1999)
- log S (water solubility)
- -2.55 ESOL (Delaney 2004), log mol/L
- Synthetic accessibility
- 1.67 SA score, 1 easy to 10 hard (Ertl and Schuffenhauer 2009)
Drug-likeness: Lipinski’s rule of five
- Molecular weight ≤ 500: 146.14
- log P ≤ 5 (Crippen): 1.79
- 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: 2,825 company reports to ECHA. Source [6].
- Acute toxicity
- Harmful or irritant
- H301Toxic if swallowed (12.1% of reports)
- H302Harmful if swallowed (84.5% of reports)
- H317May cause an allergic skin reaction (92.9% of reports)
Precautionary statements: P261, P264, P270, P272, P280, P301+P316, P301+P317, P302+P352, P321, P330, P333+P317, P362+P364, P405, P501
View all classifications (2)
- [6] European Chemicals Agency (ECHA)This chemical does not meet GHS hazard criteria for 1.5% (43 of 2825) of reports.
- [6] European Chemicals Agency (ECHA) · 2,825 reports · DangerH301, H302, H317
First aid
- Eyes: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. Immediately transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop. Skin: Immediately flood affected skin with water while removing and isolating all contaminated clothing.[1]
- Fresh air, rest.[3]
- Remove contaminated clothes. Rinse and then wash skin with water and soap.[3]
- First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.[3]
Storage
- Separated from food and feedstuffs.[3]
Safety data sheets on the supplier’s page: MuseChem, Specs, Matrix Scientific.
Always read the supplier’s safety data sheet before working with it.
Spectra
- NMRHazardous Substances Data Bank (HSDB) · NMRShiftDB
- 1H NMRHuman Metabolome Database (HMDB) (Varian · 500 MHz · CDCl3) · Human Metabolome Database (HMDB) (400 MHz · CDCl3) · Human Metabolome Database (HMDB) (400 MHz · CDCl3) · Human Metabolome Database (HMDB) (400 MHz · CDCl3) · Human Metabolome Database (HMDB) (400 MHz · CDCl3) · Human Metabolome Database (HMDB) (JEOL · 400 MHz · CDCl3)
- 13C NMRHazardous Substances Data Bank (HSDB) · Human Metabolome Database (HMDB) (NEVA · 15.09 MHz · CDCl3) · SpectraBase
- 17O NMRSpectraBase
- 1H-13C NMRHuman Metabolome Database (HMDB) (Bruker · 600 MHz · CDCl3)
- GC-MSHuman Metabolome Database (HMDB) (EI-B · positive) · Human Metabolome Database (HMDB) (EI-B · positive) · Human Metabolome Database (HMDB) (EI-B · positive) · Human Metabolome Database (HMDB) (GC-MS) · Human Metabolome Database (HMDB) (GC-MS) · MassBank of North America (MoNA) (HITACHI RMU-6M · EI-B · positive)
- MS-MSHuman Metabolome Database (HMDB) (Quattro_QQQ · Positive) · Human Metabolome Database (HMDB) (Quattro_QQQ · Positive) · Human Metabolome Database (HMDB) (Quattro_QQQ · 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 Europe (maXis (Bruker Daltonics) · LC-ESI-QTOF · POSITIVE) · MassBank Europe (maXis (Bruker Daltonics) · LC-ESI-QTOF · POSITIVE) · MassBank Europe (maXis (Bruker Daltonics) · LC-ESI-QTOF · POSITIVE) · MassBank Europe (maXis (Bruker Daltonics) · LC-ESI-QTOF · POSITIVE) · MassBank Europe (maXis (Bruker Daltonics) · LC-ESI-QTOF · POSITIVE)
- Other MSHazardous Substances Data Bank (HSDB) · MassBank Europe (HITACHI RMU-7L · EI-B · POSITIVE) · MassBank Europe (HITACHI RMU-6M · EI-B · POSITIVE) · MassBank Europe (JEOL JMS-AX-505-H · EI-B · POSITIVE) · MassBank of North America (MoNA) (qTof · positive) · MassBank of North America (MoNA) (positive)
- UVHazardous Substances Data Bank (HSDB)
- UV-VISSpectraBase
- IRHazardous Substances Data Bank (HSDB)
- FTIRSpectraBase (Bio-Rad FTS · Film (MeCl2))
- ATR-IRSpectraBase (PerkinElmer SpectrumTwo · ATR-IR)
- Vapor Phase IRSpectraBase (DIGILAB FTS-14 · Vapor Phase)
- RamanHazardous Substances Data Bank (HSDB) · SpectraBase (Bruker MultiRAM Stand Alone FT-Raman Spectrometer · 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]CAMEO Chemicals · Public domain (NOAA) · via PubChem · retrieved 2026-10-14
- [2]EPA Chemical Data Reporting (CDR) · Public domain (US EPA) · via PubChem · retrieved 2026-10-14
- [3]ILO-WHO International Chemical Safety Cards (ICSCs) · CC BY 4.0 · via PubChem · retrieved 2026-10-14
- [4]Hazardous Substances Data Bank (HSDB) · Public domain (US NLM) · via PubChem · retrieved 2026-10-14
- [5]PAC Chemical Database, U.S. Department of Energy · Public domain (US DOE) · via PubChem · retrieved 2026-10-14
- [6]European Chemicals Agency (ECHA) · ECHA legal notice: reuse with acknowledgement · via PubChem · retrieved 2026-10-14
- [7]NMRShiftDB · Linked only · via PubChem · retrieved 2026-10-14
- [8]Human Metabolome Database (HMDB) · Linked only · via PubChem · retrieved 2026-10-14
- [9]SpectraBase · Linked only · via PubChem · retrieved 2026-10-14
- [10]MassBank of North America (MoNA) · CC BY 4.0 · via PubChem · retrieved 2026-10-14
- [11]NIST Mass Spectrometry Data Center · Linked only · via PubChem · retrieved 2026-10-14
- [12]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.