Benzoyl chloride

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Benzoyl chloride
Benzoyl Chloride
Preferred IUPAC name
Benzoyl chloride
Other names
Benzoic acid chloride (1:1)
3D model (JSmol)
ECHA InfoCard 100.002.464 Edit this at Wikidata
EC Number
  • 202-710-8
RTECS number
  • DM6600000
UN number 1736
  • InChI=1S/C7H5ClO/c8-7(9)6-4-2-1-3-5-6/h1-5H checkY
  • InChI=1/C7H5ClO/c8-7(9)6-4-2-1-3-5-6/h1-5H
  • ClC(=O)c1ccccc1
  • c1ccc(cc1)C(=O)Cl
Molar mass 140.57 g·mol−1
Appearance colorless liquid
Odor Benzaldehyde like but more pungent
Density 1.21 g/mL, liquid
Melting point −1 °C (30 °F; 272 K)
Boiling point 197.2 °C (387.0 °F; 470.3 K)
reacts, forms hydrogen chloride on contact with water
-75.8·10−6 cm3/mol
Occupational safety and health (OHS/OSH):
Main hazards
Maybe harmful by ingestion and skin absorption; possible carcinogen[1]
GHS labelling:
GHS05: CorrosiveGHS07: Exclamation mark
H302, H312, H314, H317, H332
P260, P261, P264, P270, P271, P272, P280, P301+P312, P301+P330+P331, P302+P352, P303+P361+P353, P304+P312, P304+P340, P305+P351+P338, P310, P312, P321, P322, P330, P333+P313, P363, P405, P501
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gasFlammability 2: Must be moderately heated or exposed to relatively high ambient temperature before ignition can occur. Flash point between 38 and 93 °C (100 and 200 °F). E.g. diesel fuelInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazard W: Reacts with water in an unusual or dangerous manner. E.g. sodium, sulfuric acid
Flash point 72 °C (162 °F; 345 K)
Safety data sheet (SDS) Fisher Scientific MSDS
Related compounds
Related compounds
benzoic acid, benzoic anhydride, benzaldehyde
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Benzoyl chloride, also known as benzenecarbonyl chloride, is an organochlorine compound with the formula C7H5ClO. It is a colourless, fuming liquid with an irritating odour, and consists of a benzene ring (C6H6) with an acyl chloride (−C(=O)Cl) substituent. It is mainly useful for the production of peroxides but is generally useful in other areas such as in the preparation of dyes, perfumes, pharmaceuticals, and resins.


Benzoyl chloride is produced from benzotrichloride using either water or benzoic acid:[2]

C6H5CCl3 + H2O → C6H5COCl + 2 HCl
C6H5CCl3 + C6H5CO2H → 2 C6H5COCl + HCl

As with other acyl chlorides, it can be generated from the parent acid and standard chlorinating agents such as phosphorus pentachloride, thionyl chloride, and oxalyl chloride. It was first prepared by treatment of benzaldehyde with chlorine.[3]

An early method for production of benzoyl chloride involved chlorination of benzyl alcohol.[4]


It reacts with water to produce hydrochloric acid and benzoic acid:

C6H5COCl + H2O → C6H5COOH + HCl

Benzoyl chloride is a typical acyl chloride. It reacts with alcohols to give the corresponding esters. Similarly, it reacts with amines to give the amide.[5][6]

It undergoes the Friedel-Crafts acylation with aromatic compounds to give the corresponding benzophenones and related derivatives.[7] With carbanions, it serves again as a source of the benzoyl cation synthon, C6H5CO+.[8]

Benzoyl peroxide, a common reagent in polymer chemistry, is produced industrially by treating benzoyl chloride with hydrogen peroxide and sodium hydroxide:[9]

2 C6H5COCl + H2O2 + 2 NaOH → (C6H5CO)2O2 + 2 NaCl + 2 H2O


  1. ^ Benzoyl chloride: toxicity and precautions
  2. ^ Maki, Takao; Takeda, Kazuo (2000). "Benzoic Acid and Derivatives". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a03_555. ISBN 978-3527306732.
  3. ^ Friedrich Wöhler, Justus von Liebig (1832). "Untersuchungen über das Radikal der Benzoesäure". Annalen der Pharmacie. 3 (3): 262–266. doi:10.1002/jlac.18320030302. hdl:2027/hvd.hxdg3f.
  4. ^ US1851832, 29 March 1932
  5. ^ Marvel, C. S.; Lazier, W. A. (1929). "Benzoyl Piperidine". Organic Syntheses. 9: 16. doi:10.15227/orgsyn.009.0016.
  6. ^ Prasenjit Saha, Md Ashif Ali, and Tharmalingam Punniyamurthy "Ligand-free Copper(ii) Oxide Nanoparticles Catalyzed Synthesis Of Substituted Benzoxazoles" Org. Synth. 2011, volume 88, pp. 398. doi:10.15227/orgsyn.088.0398. (an illustrative reaction of an amine with benzoyl chloride).
  7. ^ Minnis, Wesley (1932). "Phenyl Thienyl Ketone". Organic Syntheses. 12: 62. doi:10.15227/orgsyn.012.0062.
  8. ^ Fujita, M.; Hiyama, T. (1990). "Directed Reduction of a beta-keto Amide: Erythro-1-(3-hydroxy-2-methyl-3-phenylpropanoyl)piperidine". Organic Syntheses. 69: 44. doi:10.15227/orgsyn.069.0044.
  9. ^ El-Samragy, Yehia (2004). "Chemical and Technical Assessment". Benzoyl Peroxide (PDF). 61st JECFA (Technical report). Joint FAO/WHO Expert Committee on Food Additives. p. 1. Retrieved 31 October 2013.

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