Benzal chloride

Benzal chloride is an organic compound with the formula C₆H₅CHCl₂.[1] This colourless liquid is a lachrymator and is used as a building block in organic synthesis.

Benzal chloride

Skeletal formula of benzal chloride Ball-and-stick model of benzal chloride
Names
Preferred IUPAC name (Dichloromethyl)benzene
Other names Benzyl dichloride Benzylidene chloride α,α-Dichlorotoluene PhCl2H
Identifiers
CAS Number	98-87-3
3D model (JSmol)	Interactive image
Beilstein Reference	1099407
ChEBI	CHEBI:82273
ChEMBL	ChEMBL1412576
ChemSpider	13882337
ECHA InfoCard	100.002.463
EC Number	249-854-8
KEGG	C19165
MeSH	Compounds Benzylidene Compounds
PubChem CID	7411
RTECS number	CZ5075000
UNII	222447TR16
UN number	1886 2810
CompTox Dashboard (EPA)	DTXSID6025014
InChI InChI=1S/C7H6Cl2/c8-7(9)6-4-2-1-3-5-6/h1-5,7H Key: CAHQGWAXKLQREW-UHFFFAOYSA-N
SMILES ClC(Cl)c1ccccc1 C1=CC=C(C=C1)C(Cl)Cl
Properties
Chemical formula	C7H6Cl2
Molar mass	161.03 g/mol
Appearance	Colorless liquid
Density	1.254 g/cm^3, liquid
Melting point	−17 to −15 °C (1 to 5 °F; 256 to 258 K)
Boiling point	205 °C (401 °F; 478 K) (82 °C at 10 mmHg)
Solubility in water	0.25 g/L at 39 °C
Vapor pressure	0.6 kPa (45 °C)
Hazards
GHS pictograms
GHS Signal word	Danger
GHS hazard statements	H302, H315, H318, H331, H335, H351
GHS precautionary statements	P201, P202, P261, P264, P270, P271, P280, P281, P301+312, P302+352, P304+340, P305+351+338, P308+313, P310, P311, P312, P321, P330, P332+313, P362, P403+233, P405, P501
Flash point	93 °C (199 °F; 366 K)
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

Preparation and usage

Benzal chloride is produced by the free radical chlorination of toluene, being preceded in the process by benzyl chloride (C₆H₅CH₂Cl) and followed by benzotrichloride (C₆H₅CCl₃):

C₆H₅CH₃ + Cl₂ → C₆H₅CH₂Cl + HCl

C₆H₅CH₂Cl + Cl₂ → C₆H₅CHCl₂ + HCl

C₆H₅CHCl₂ + Cl₂ → C₆H₅CCl₃ + HCl

Benzylic halides are typically strong alkylating agents, and for this reason benzal chloride is treated as a hazardous compound.

Treatment of benzal chloride with sodium gives stilbene.

Most benzal chloride main industrial use is as a precursor to benzaldehyde. This conversion involves hydrolysis in the presence of base:[2]

C₆H₅CHCl₂ + H₂O → C₆H₅CHO + 2 HCl

References

1. "BENZAL CHLORIDE". International Programme on Chemical Safety. Retrieved 2007-10-30.
2. Lipper, Karl-August; Löser, Eckhard. "Benzyl Chloride and Other Side-Chain Chlorinated Aromatic Hydrocarbons". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.o04_o01.