Acetanilide (C8H9NO): structure, properties and hazards

Names and identifiers

IUPAC name: N-phenylacetamide
Synonyms: antifebrin, N-phenylacetamide, N-Phenylacetamide
+ 37 more
Antifebrin, N-Acetylaniline, Acetanilid, Acetamidobenzene, Acetanil, Acetylaniline, Phenalgene, Acetamide, N-phenyl-, Acetylaminobenzene, Acetic acid anilide, Acetoanilide, Phenalgin, Aniline, N-acetyl-, USAF EK-3, Benzenamine, N-acetyl-, Acetanilidum, Antifebrinum, NSC-7636, SP86R356CC, NSC-203231, CHEBI:28884, RefChem:6369, 203-150-7, 695-031-5, N-acetylarylamine, N-Acetylaminobenzene, AN [Analgesic], NSC 7636, MFCD00008674, Ethananilide, N-Phenyl-acetamide, DTXSID2022543, Acetanilide (Antifebrin), Acetanilide (Acetylaniline), NSC7636, N-Phenylacetamide;N-Phenylacetamide, NCGC00091326-01
Molecular formula: C₈H₉NO
Empirical formula: C₈H₉NO
Molecular weight: 135.16 g/mol
Exact mass: 135.06841
CAS number: 103-84-4
PubChem CID: 904
Canonical SMILES: CC(=O)NC1=CC=CC=C1
Isomeric SMILES: CC(=O)NC1=CC=CC=C1
InChI: InChI=1S/C8H9NO/c1-7(10)9-8-5-3-2-4-6-8/h2-6H,1H3,(H,9,10)
InChIKey: FZERHIULMFGESH-UHFFFAOYSA-N
Molfile

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

Physical properties

TemperaturePressureDensity

Appearance: Colorless, glossy, crystalline material.[2]
4 values
From Hazardous Substances Data Bank (HSDB), the most authoritative source here.
Value As written Source
– Acetanilide is a white to gray solid. (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.
– WHITE SHINING CRYSTALLINE SCALES [2] Hazardous Substances Data Bank (HSDB)cites Sax, N.I. Dangerous Properties of Industrial Materials. 5th ed. New York: Van Nostrand Rheinhold, 1979., p. 332
– White, shining crystalline leaflets or white crystalline powder. [2] Hazardous Substances Data Bank (HSDB)cites Lewis, R.J., Sr (Ed.). Hawley's Condensed Chemical Dictionary. 12th ed. New York, NY: Van Nostrand Rheinhold Co., 1993, p. 6
–shown Colorless, glossy, crystalline material. [2] 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. VA2 310
Odor: ODORLESS[2]
Melting point: 114.3 °C[3]
2 values
2 of 2 sources agree on it (most common value).
Value As written Source
114.3 °C 237.7 °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.
114.3 °Cshown 114.3 °C [3] PAC Chemical Database, U.S. Department of Energy
Boiling point: 304 °C @760 [mmHg][3]
2 values
2 of 2 sources agree on it (most common value).
Value As written Source
304 °C 579 °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.
304 °Cshown 304 °C @760 [mm Hg] [3] PAC Chemical Database, U.S. Department of Energy
Density: 1.219 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 1.219 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.
– 1.21 @ 20°C [3] PAC Chemical Database, U.S. Department of Energy
Solubility in water: Water solubility= 6.93 × 10³ mg/l at 25 °C[2]
2 values
From Hazardous Substances Data Bank (HSDB), the most authoritative source here.
Value As written Source
– less than 1 mg/mL at 72 °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.
–shown Water solubility= 6.93X10+3 mg/l at 25 °C [2] Hazardous Substances Data Bank (HSDB)cites Yalkowsky SH, Dannenfelser RM; The Aquasol Database of Aqueous Solubility. Fifth ed, Tucson, AZ: Univ AZ, College of Pharmacy, PC Ver. (1992)
log P: Log Kow= 1.16[2]
pKa: pKa = 0.50 at 25 °C (conjugate acid)[2]
Vapor pressure: 1.22 × 10⁻³ mmHg at 25 °C[2]
3 values
Sources disagree; from Hazardous Substances Data Bank (HSDB), the most authoritative.
Value As written Source
1 mmHg 1 mmHg at 237 °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.
0.00122 mmHgshown 1.22X10-3 mm Hg at 25 °C [2] Hazardous Substances Data Bank (HSDB)cites Perry RH, Green D; Perry's Chemical Handbook, 6th ed. NY, NY: McGraw Hill p 3-50 (1984)
0.000003 mmHg 0.000003 [mm Hg] @20 °C [3] PAC Chemical Database, U.S. Department of Energy
Flash point: 169 °C (337 °F)[2]
3 values
Sources disagree; from Hazardous Substances Data Bank (HSDB), the most authoritative.
Value As written Source
174 °C 345 °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.
169 °Cshown 337 °F [2] Hazardous Substances Data Bank (HSDB)cites Fire Protection Guide to Hazardous Materials. 12 ed. Quincy, MA: National Fire Protection Association, 1997., p. 325-10
169 °C 169 °C (OPEN CUP) [2] Hazardous Substances Data Bank (HSDB)cites Fire Protection Guide to Hazardous Materials. 12 ed. Quincy, MA: National Fire Protection Association, 1997., p. 325-10
Autoignition temperature: 540 °C (1004 °F, NTP 1992)[1]

Value	As written	Source
–	Acetanilide is a white to gray solid. (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.
–	WHITE SHINING CRYSTALLINE SCALES	[2] Hazardous Substances Data Bank (HSDB)cites Sax, N.I. Dangerous Properties of Industrial Materials. 5th ed. New York: Van Nostrand Rheinhold, 1979., p. 332
–	White, shining crystalline leaflets or white crystalline powder.	[2] Hazardous Substances Data Bank (HSDB)cites Lewis, R.J., Sr (Ed.). Hawley's Condensed Chemical Dictionary. 12th ed. New York, NY: Van Nostrand Rheinhold Co., 1993, p. 6
–shown	Colorless, glossy, crystalline material.	[2] 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. VA2 310

Value	As written	Source
114.3 °C	237.7 °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.
114.3 °Cshown	114.3 °C	[3] PAC Chemical Database, U.S. Department of Energy

Value	As written	Source
304 °C	579 °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.
304 °Cshown	304 °C @760 [mm Hg]	[3] PAC Chemical Database, U.S. Department of Energy

Value	As written	Source
–shown	1.219 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.
–	1.21 @ 20°C	[3] PAC Chemical Database, U.S. Department of Energy

Value	As written	Source
–	less than 1 mg/mL at 72 °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.
–shown	Water solubility= 6.93X10+3 mg/l at 25 °C	[2] Hazardous Substances Data Bank (HSDB)cites Yalkowsky SH, Dannenfelser RM; The Aquasol Database of Aqueous Solubility. Fifth ed, Tucson, AZ: Univ AZ, College of Pharmacy, PC Ver. (1992)

Value	As written	Source
1 mmHg	1 mmHg at 237 °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.
0.00122 mmHgshown	1.22X10-3 mm Hg at 25 °C	[2] Hazardous Substances Data Bank (HSDB)cites Perry RH, Green D; Perry's Chemical Handbook, 6th ed. NY, NY: McGraw Hill p 3-50 (1984)
0.000003 mmHg	0.000003 [mm Hg] @20 °C	[3] PAC Chemical Database, U.S. Department of Energy

Value	As written	Source
174 °C	345 °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.
169 °Cshown	337 °F	[2] Hazardous Substances Data Bank (HSDB)cites Fire Protection Guide to Hazardous Materials. 12 ed. Quincy, MA: National Fire Protection Association, 1997., p. 325-10
169 °C	169 °C (OPEN CUP)	[2] Hazardous Substances Data Bank (HSDB)cites Fire Protection Guide to Hazardous Materials. 12 ed. Quincy, MA: National Fire Protection Association, 1997., p. 325-10

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: 10
Rings: 1
Aromatic rings: 1
Fraction sp³ carbons (Fsp3): 0.12
H-bond donors: 1
H-bond acceptors: 1
Rotatable bonds: 1
TPSA (Å²): 29.1
Formal charge: 0
XLogP3: 1.2 PubChem
Complexity: 116 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

C71.09%
H6.71%
N10.36%
O11.84%

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: 1.64 Crippen (Wildman and Crippen 1999)
log S (water solubility): -2.09 ESOL (Delaney 2004), log mol/L
Synthetic accessibility: 1.11 SA score, 1 easy to 10 hard (Ertl and Schuffenhauer 2009)

Drug-likeness: Lipinski’s rule of five

Molecular weight ≤ 500: 135.17
log P ≤ 5 (Crippen): 1.64
H-bond donors ≤ 5: 1
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: 1,686 company reports to ECHA. Source [4].

Harmful or irritant

NFPA 704[2]

H302Harmful if swallowed (99.9% of reports)

Precautionary statements: P264, P270, P301+P317, P330, P501

View all classifications (3)

[4] European Chemicals Agency (ECHA)This chemical does not meet GHS hazard criteria for 0.1% (2 of 1686) of reports.
[4] European Chemicals Agency (ECHA) · 1,686 reports · WarningH302
[4] European Chemicals Agency (ECHA) · WarningH302, H315, H319, H335

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]

Incompatibilities

SEE aniline...CAN react vigorously WITH oxidizing materials.[2]

Safety data sheets on the supplier’s page: Biorbyt, Synthonix, Inc., 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]CAMEO Chemicals · Public domain (NOAA) · via PubChem · retrieved 2026-10-14
[2]Hazardous Substances Data Bank (HSDB) · Public domain (US NLM) · via PubChem · retrieved 2026-10-14
[3]PAC Chemical Database, U.S. Department of Energy · Public domain (US DOE) · 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]SpectraBase · Linked only · via PubChem · retrieved 2026-10-14
[7]Human Metabolome Database (HMDB) · 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.

Similar structures

Tanimoto similarity on Morgan fingerprints (radius 2) with RDKit 2026.09, at least 45%.