Benzoyl chloride

Benzoyl chloride, also known as benzenecarbonyl chloride, is an organochlorine compound with the formula C6H5COCl. It is a colourless, fuming liquid with an irritating odour. 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
Benzoyl Chloride
Preferred IUPAC name
Benzoyl chloride
3D model (JSmol)
ECHA InfoCard 100.002.464 Edit this at Wikidata
EC Number
  • 202-710-8
RTECS number
  • DM6600000
UN number 1736
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)
-75.8·10−6 cm3/mol
Safety data sheet Fisher Scientific MSDS
GHS pictograms GHS05: CorrosiveGHS07: Harmful
GHS Signal word Danger
H302, H312, H314, H317, H332
P260, P261, P264, P270, P271, P272, P280, P301+312, P301+330+331, P302+352, P303+361+353, P304+312, P304+340, P305+351+338, P310, P312, P321, P322, P330, P333+313, P363, P405, P501
NFPA 704 (fire diamond)
Flammability code 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 fuelHealth code 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gasReactivity code 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 acidNFPA 704 four-colored diamond
Flash point 72 °C (162 °F; 345 K)
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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Infobox references


Benzoyl chloride is produced from benzotrichloride using either water or benzoic acid:[1]

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

As with other acyl chlorides, it can be generated from the parent acid and other chlorinating agents phosphorus pentachloride, thionyl chloride, or oxalyl chloride. It was first prepared by treatment of benzaldehyde with chlorine.[2]

An early method for production of benzoyl chloride involved chlorination of benzyl alcohol.[3]


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

C6H5COCl + H2O → C6H5CO2H + 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.[4][5]

It undergoes the Friedel-Crafts acylation with aromatic compounds to give the corresponding benzophenones and related derivatives.[6] With carbanions, it serves again as a source of "PhCO+".[7]

Benzoyl peroxide, a common reagent in polymer chemistry, is produced industrially by treating benzoyl chloride with hydrogen peroxide and sodium hydroxide:[8]

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


  1. ^ Maki, Takao; Takeda, Kazuo (2000). "Benzoic Acid and Derivatives". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a03_555.
  2. ^ 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.
  3. ^ US1851832, 29 March 1932
  4. ^ Marvel, C. S.; Lazier, W. A. (1929). "Benzoyl Piperidine". Organic Syntheses. 9: 16. doi:10.15227/orgsyn.009.0016.
  5. ^ 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).
  6. ^ Minnis, Wesley (1932). "Phenyl Thienyl Ketone". Organic Syntheses. 12: 62. doi:10.15227/orgsyn.012.0062.
  7. ^ 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.
  8. ^ 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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