Benzofuran

Athanor · official

C₈H₆O · 118.13 g/mol

IUPAC name: 1-benzofuran

Also called coumarone, benzo[b]furan

Rings

Open in Athanor

Drawn from its SMILES with RDKit

WarningFlammable liquid and vapor · Suspected of causing cancer · Harmful to aquatic life with long lasting effects

Names and identifiers

IUPAC name: 1-benzofuran
Synonyms: coumarone, benzo[b]furan, 2,3-Benzofuran
+ 37 more
Coumarone, 1-Benzofuran, Benzo[b]furan, Cumarone, Benzofurfuran, Benzo(b)furan, 1-Oxindene, Coumaron, 1-Oxidene, Benzofuran (IUPAC), NCI-C56166, DTXSID6020141, NSC-1255, LK6946W774, DTXCID20141, CHEBI:35260, AT 33852, RefChem:118279, CHEBI:36790, 205-982-6, benzo[b]furane, MFCD00005847, Benzofuran (1mg/mL In Dichloromethane), CHEMBL363614, NCGC00091088-05, Cumaron, CCRIS 2384, HSDB 4173, NSC 1255, EINECS 205-982-6, bezofuran, BRN 0107704, AI3-17613, UNII-LK6946W774, 1-Oxaindene, 1-Benzofuran #, BENZOFURAN [MI]
Molecular formula: C₈H₆O
Empirical formula: C₈H₆O
Molecular weight: 118.13 g/mol
Exact mass: 118.04186
CAS number: 271-89-6
PubChem CID: 9223
Canonical SMILES: C1=CC=C2C(=C1)C=CO2
Isomeric SMILES: C1=CC=C2C(=C1)C=CO2
InChI: InChI=1S/C8H6O/c1-2-4-8-7(3-1)5-6-9-8/h1-6H
InChIKey: IANQTJSKSUMEQM-UHFFFAOYSA-N
Molfile

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

Physical properties

TemperaturePressureDensity

Appearance: Colorless, oily liquid[3]
3 values
From Hazardous Substances Data Bank (HSDB), the most authoritative source here.
Value As written Source
– 2,3-benzofuran is a clear oily yellow liquid with an aromatic odor. (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.
– COLOURLESS OILY LIQUID WITH CHARACTERISTIC ODOUR. [2] ILO-WHO International Chemical Safety Cards (ICSCs)
–shown Colorless, oily liquid [3] 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
Melting point: less than -18.0 °C (-0.4 °F, NTP 1992)[1]
Boiling point: 174 °C[2]
2 values
2 of 2 sources agree on it (most common value).
Value As written Source
174 °C 345 °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.
174 °Cshown 174 °C [2] ILO-WHO International Chemical Safety Cards (ICSCs)
Density: 1.078 at 15 °C (59 °F) (NTP, 1992) - Denser than water[1]
2 values
2 of 2 sources agree on it (most common value).
Value As written Source
–shown 1.078 at 59 °F (NTP, 1992) - Denser 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.
– Relative density (water = 1): 1.09 [2] ILO-WHO International Chemical Safety Cards (ICSCs)
Solubility in water: Solubility in water: none[2]
3 values
From ILO-WHO International Chemical Safety Cards (ICSCs), the most authoritative source here.
Value As written Source
– 0.1 to 1 mg/mL at 64 °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 ethanol. [3] Hazardous Substances Data Bank (HSDB)cites Gerhartz, W. (exec ed.). Ullmann's Encyclopedia of Industrial Chemistry. 5th ed.Vol A1: Deerfield Beach, FL: VCH Publishers, 1985 to Present., p. VA12 (1989) 130
–shown Solubility in water: none [2] ILO-WHO International Chemical Safety Cards (ICSCs)
log P: 2.67[2]
2 values
2 of 2 sources agree on it (most common value).
Value As written Source
– log Kow= 2.67 [3] 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. 38
–shown 2.67 [2] ILO-WHO International Chemical Safety Cards (ICSCs)
Vapor pressure: Vapor pressure, kPa at 25 °C: 0.06[2]
3 values
2 of 3 sources agree on it (most common value).
Value As written Source
14.3 mmHg 14.3 mmHg at 77 °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.
0.44 mmHg 0.44 mm Hg at 25 °C [3] Hazardous Substances Data Bank (HSDB)cites Chao J et al; J Phys Chem Ref Data 12: 1033-63 (1983)
0.45 mmHgshown Vapor pressure, kPa at 25 °C: 0.06 [2] ILO-WHO International Chemical Safety Cards (ICSCs)
Flash point: 56 °C (133 °F, NTP 1992)[1]
2 values
2 of 2 sources agree on it (most common value).
Value As written Source
56 °Cshown 133 °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.
56 °C 56 °C [2] ILO-WHO International Chemical Safety Cards (ICSCs)

Value	As written	Source
–	2,3-benzofuran is a clear oily yellow liquid with an aromatic odor. (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.
–	COLOURLESS OILY LIQUID WITH CHARACTERISTIC ODOUR.	[2] ILO-WHO International Chemical Safety Cards (ICSCs)
–shown	Colorless, oily liquid	[3] 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

Value	As written	Source
174 °C	345 °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.
174 °Cshown	174 °C	[2] ILO-WHO International Chemical Safety Cards (ICSCs)

Value	As written	Source
–shown	1.078 at 59 °F (NTP, 1992) - Denser 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.
–	Relative density (water = 1): 1.09	[2] ILO-WHO International Chemical Safety Cards (ICSCs)

Value	As written	Source
–	0.1 to 1 mg/mL at 64 °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 ethanol.	[3] Hazardous Substances Data Bank (HSDB)cites Gerhartz, W. (exec ed.). Ullmann's Encyclopedia of Industrial Chemistry. 5th ed.Vol A1: Deerfield Beach, FL: VCH Publishers, 1985 to Present., p. VA12 (1989) 130
–shown	Solubility in water: none	[2] ILO-WHO International Chemical Safety Cards (ICSCs)

Value	As written	Source
–	log Kow= 2.67	[3] 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. 38
–shown	2.67	[2] ILO-WHO International Chemical Safety Cards (ICSCs)

Value	As written	Source
14.3 mmHg	14.3 mmHg at 77 °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.
0.44 mmHg	0.44 mm Hg at 25 °C	[3] Hazardous Substances Data Bank (HSDB)cites Chao J et al; J Phys Chem Ref Data 12: 1033-63 (1983)
0.45 mmHgshown	Vapor pressure, kPa at 25 °C: 0.06	[2] ILO-WHO International Chemical Safety Cards (ICSCs)

Value	As written	Source
56 °Cshown	133 °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.
56 °C	56 °C	[2] 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: 9
Rings: 2
Aromatic rings: 2
Fraction sp³ carbons (Fsp3): 0
H-bond donors: 0
H-bond acceptors: 1
Rotatable bonds: 0
TPSA (Å²): 13.1
Formal charge: 0
XLogP3: 2.7 PubChem
Complexity: 101 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

C81.34%
H5.12%
O13.54%

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: 2.43 Crippen (Wildman and Crippen 1999)
log S (water solubility): -2.85 ESOL (Delaney 2004), log mol/L
Synthetic accessibility: 1.8 SA score, 1 easy to 10 hard (Ertl and Schuffenhauer 2009)

Drug-likeness: Lipinski’s rule of five

Molecular weight ≤ 500: 118.13
log P ≤ 5 (Crippen): 2.43
H-bond donors ≤ 5: 0
H-bond acceptors ≤ 10: 1

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: 65 company reports to ECHA. Source [4].

Flammable
Health hazard

H226Flammable liquid and vapor
H351Suspected of causing cancer (95.4% of reports)
H412Harmful to aquatic life with long lasting effects (63.1% of reports)

Precautionary statements: P203, P210, P233, P240, P241, P242, P243, P273, P280, P303+P361+P353, P318, P370+P378, P403+P235, P405, P501

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]

Storage

Fireproof. Well closed. Cool.[2]
Precautions FOR "carcinogens": Storage site should be as close as practical to lab in which carcinogens are to be used, so that only small quantities required for ... Expt need to be carried. Carcinogens should be kept in only one section of cupboard, an explosion-proof refrigerator or freezer (depending on chemicophysical properties ...) that bears appropriate label. An inventory ... Should be kept, showing quantity of carcinogen & date it was acquired ... Facilities for dispensing ... Should be contiguous to storage area. (chemical Carcinogens)[3]
You should keep this material in a tightly closed container under an inert atmosphere, and store it at refrigerated temperatures. Store AWAY FROM sources OF ignition.[3]

Incompatibilities

This compound is polymerized by H2SO4.[3]

Safety data sheets on the supplier’s page: Sinfoo Biotech, RR Scientific, Thermo Fisher Scientific.

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]CAMEO Chemicals · Public domain (NOAA) · via PubChem · retrieved 2026-10-14
[2]ILO-WHO International Chemical Safety Cards (ICSCs) · CC BY 4.0 · via PubChem · retrieved 2026-10-14
[3]Hazardous Substances Data Bank (HSDB) · Public domain (US NLM) · via PubChem · retrieved 2026-10-14
[4]European Chemicals Agency (ECHA) · ECHA legal notice: reuse with acknowledgement · via PubChem · retrieved 2026-10-14
[5]NMRShiftDB · Linked only · via PubChem · retrieved 2026-10-14
[6]Human Metabolome Database (HMDB) · Linked only · via PubChem · retrieved 2026-10-14
[7]SpectraBase · Linked only · via PubChem · retrieved 2026-10-14
[8]MassBank of North America (MoNA) · CC BY 4.0 · via PubChem · retrieved 2026-10-14
[9]NIST Mass Spectrometry Data Center · Linked only · via PubChem · retrieved 2026-10-14
[10]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.