Benzoyl chloride
An aromatic acyl chloride connecting benzoic-acid derivatives.
- Formula
- C7H5ClO
- Functional group
- Acyl chlorides
- Molar mass
- 140.56 g/mol
- Also known as
- Benzenecarbonyl chloride, Benzoic acid, chloride, alpha-Chlorobenzaldehyde, benzoic acid chloride, Benzaldehyde, alpha-chloro-
Overview
An aromatic acyl chloride connecting benzoic-acid derivatives.
Chlorine is attached to the carbonyl carbon, not directly to the aromatic ring. Nucleophilic acyl substitution can give benzoic acid, a benzoate ester or benzamide. These transformations retain the benzoyl carbonyl and produce an HCl equivalent that affects work-up.
Identifiers
- Formula
- C7H5ClO
- Functional group
- Acyl chlorides
- Molar mass
- 140.56 g/mol
- Also known as
- Benzenecarbonyl chloride, Benzoic acid, chloride, alpha-Chlorobenzaldehyde, benzoic acid chloride, Benzaldehyde, alpha-chloro-
Chemical identifiers
- SMILES
- C1=CC=C(C=C1)C(=O)Cl
- InChI
- InChI=1S/C7H5ClO/c8-7(9)6-4-2-1-3-5-6/h1-5H
- PubChem CID
- 7412
Properties
- Melting Point
- -0.5 °C
- Boiling Point
- BP: 197.2 °C at 760 mm Hg
- Relative density (water = 1)
- Relative density (water = 1): 1.21
- Water solubility
- Solubility in water: reaction
Related compounds
- Acyl chlorides
An aromatic acyl chloride connecting benzoic-acid derivatives.
Connected reactions
- Acyl chloride preparation: Benzoic acid → Benzoyl chloride
Reaction with phosphorus(V) chloride replaces the carboxyl OH group with chlorine, retaining the acyl carbon and aromatic ring. The new acyl chloride is more susceptible to nucleophilic substitution, while POCl3 and HCl account for the remaining atoms.
- Amide formation: Benzoyl chloride → Benzamide
Ammonia adds to the acyl carbonyl to form a tetrahedral intermediate. Carbonyl re-formation expels chloride, and proton transfer gives benzamide; additional ammonia captures the acid as ammonium chloride.
- Ester formation: Benzoyl chloride → Ethyl benzoate
Ethanol oxygen attacks the acyl carbonyl carbon. Loss of chloride and proton transfer restore C=O and form the ester, with ethanol contributing the ethoxy group and HCl produced in the overall equation.
References
- PubChem Compound Summary: Benzoyl chloride (CID 7412)National Center for Biotechnology Information · PubChem
Identity, molecular formula, molecular weight and aliases retrieved via PUG REST on 2026-09-08.
- OpenStax Organic Chemistry: Chemistry of acid halidesJohn McMurry · OpenStax · 2023
Supports the qualitative structural interpretation of the recorded molecular structure; no new physical measurement or verified preparative yield is claimed.
- Hazardous Substances Data Bank (HSDB): Benzoyl chloride — melting pointHazardous Substances Data Bank (HSDB)
Retrieved through PubChem PUG View on 2026-09-08. https://pubchem.ncbi.nlm.nih.gov/compound/7412#section=Melting-Point. Source value, complete property clause or compact miscibility statement retained; absent pressure, temperature or phase conditions are not inferred. Original reference: Haynes, W.M. (ed.). CRC Handbook of Chemistry and Physics. 95th Edition. CRC Press LLC, Boca Raton: FL 2014-2015, p. 3-42
- Hazardous Substances Data Bank (HSDB): Benzoyl chloride — boiling pointHazardous Substances Data Bank (HSDB)
Retrieved through PubChem PUG View on 2026-09-08. https://pubchem.ncbi.nlm.nih.gov/compound/7412#section=Boiling-Point. Source value, complete property clause or compact miscibility statement retained; absent pressure, temperature or phase conditions are not inferred. Original reference: O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Cambridge, UK: Royal Society of Chemistry, 2013., p. 196
- ILO-WHO International Chemical Safety Cards (ICSCs): Benzoyl chloride — densityILO-WHO International Chemical Safety Cards (ICSCs)
Retrieved through PubChem PUG View on 2026-09-08. https://pubchem.ncbi.nlm.nih.gov/compound/7412#section=Density. Source value, complete property clause or compact miscibility statement retained; absent pressure, temperature or phase conditions are not inferred.
- ILO-WHO International Chemical Safety Cards (ICSCs): Benzoyl chloride — solubilityILO-WHO International Chemical Safety Cards (ICSCs)
Retrieved through PubChem PUG View on 2026-09-08. https://pubchem.ncbi.nlm.nih.gov/compound/7412#section=Solubility. Source value, complete property clause or compact miscibility statement retained; absent pressure, temperature or phase conditions are not inferred.