Benzoyl chloride

Not to be confused with benzyl chloride.

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.^[1]

Benzoyl chloride

Benzoyl Chloride
Names
Preferred IUPAC name Benzoyl chloride
Other names Benzoic acid chloride (1:1)
Identifiers
CAS Number	98-88-4 Y
3D model (JSmol)	Interactive image Interactive image
ChEBI	CHEBI:82275
ChEMBL	ChEMBL2260719
ChemSpider	7134 Y
ECHA InfoCard	100.002.464
EC Number	202-710-8
KEGG	C19168 Y
PubChem CID	7412
RTECS number	DM6600000
UNII	VTY8706W36
UN number	1736
CompTox Dashboard (EPA)	DTXSID9026631
InChI InChI=1S/C7H5ClO/c8-7(9)6-4-2-1-3-5-6/h1-5H Y Key: PASDCCFISLVPSO-UHFFFAOYSA-N Y InChI=1/C7H5ClO/c8-7(9)6-4-2-1-3-5-6/h1-5H Key: PASDCCFISLVPSO-UHFFFAOYAL
SMILES ClC(=O)c1ccccc1 c1ccc(cc1)C(=O)Cl
Properties
Chemical formula	C7H5ClO
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)
Solubility in water	reacts, forms hydrogen chloride on contact with water
Magnetic susceptibility (χ)	−75.8·10−6 cm3/mol
Hazards
Occupational safety and health (OHS/OSH):
Main hazards	harmful by ingestion and skin absorption
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H302, H312, H314, H317, H332
Precautionary statements	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)	3 2 0 W
Flash point	72 °C (162 °F; 345 K)
Safety data sheet (SDS)	Fisher Scientific MSDS
Structure
Point group	Cs
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). Y verify (what is YN ?) Infobox references

Preparation

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 standard chlorinating agents such as phosphorus pentachloride, thionyl chloride, and 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]

Reactions

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.^[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 the benzoyl cation synthon, C₆H₅CO⁺.^[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

Modified benzoyl chlorides

Many substituted derivatives of benzoyl chloride are known. 4-Nitrobenzoyl chloride is a precursor to the anesthetic procaine.^[1] One example is 4-chlorobenzoyl chloride, a precursor to 4-chloro-4'-hydroxybenzophenone, which is used to make high performance polymers.^[9]

Safety

Benzoyl chloride is toxic and a serious skin irritant.^[1]