Benzyl chloride

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Benzyl chloride

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Not to be confused with benzoyl chloride.

Names

Preferred IUPAC name

(Chloromethyl)benzene

Other names

α-Chlorotoluene
Benzyl chloride

Identifiers

CAS Number

• 100-44-7 

3D model (JSmol)

• Interactive image
• Interactive image

Abbreviations

BnCl

ChEBI

• CHEBI:615597 

ChEMBL

• ChEMBL498878 

ChemSpider

• 13840690 

ECHA InfoCard

100.002.594

EC Number

202-853-6

KEGG

• C19167 

PubChem CID

• 7503

UNII

• 83H19HW7K6 

InChI[show]

SMILES[show]

Properties

Chemical formula

C₇H₇Cl

Molar mass

126.58 g/mol

Appearance

colorless to slightly yellow liquid

Odor

pungent, aromatic^[1]

Density

1.100 g/cm³

Melting point

−39 °C (−38 °F; 234 K)

Boiling point

179 °C (354 °F; 452 K)

Solubility in water

very slightly soluble (0.05% at 20 °C)^[1]

Solubility

soluble in ethanol, ethyl ether, chloroform, CCl₄ 
miscible in organic solvents

Vapor pressure

1 mmHg (20 °C)^[1]

Magnetic susceptibility (χ)

-81.98·10⁻⁶ cm³/mol

Refractive index(n_D)

1.5415 (15 °C)

Hazards

Safety data sheet

External MSDS

NFPA 704

2

3

1

Flash point

67 °C (153 °F; 340 K)

Autoignition
temperature

585 °C (1,085 °F; 858 K)

Explosive limits

≥1.1%^[1]

Lethal dose or concentration (LD, LC):

LD₅₀ (median dose)

1231 mg/kg (rat, oral)

LC₅₀ (median concentration)

150 ppm (rat, 2 hr)
80 ppm (mouse, 2 hr)^[2]

LC_Lo (lowest published)

380 ppm (dog, 8 hr)^[2]

US health exposure limits (NIOSH):

PEL(Permissible)

TWA 1 ppm (5 mg/m³)^[1]

REL(Recommended)

C 1 ppm (5 mg/m³) [15-minute]^[1]

IDLH(Immediate danger)

10 ppm^[1]

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

Benzyl chloride, or α-chlorotoluene, is an organic compound with the formula C₆H₅CH₂Cl. This colourless liquid is a reactive organochlorine compound that is a widely used chemical building block.

Contents

• 1Preparation
• 2Uses and reactions
• 3Safety
• 4See also
• 5References
• 6External links

Preparation[edit]

Benzyl chloride is prepared industrially by the gas-phase photochemical reaction of toluene with chlorine:^[3]

C₆H₅CH₃ + Cl₂ → C₆H₅CH₂Cl + HCl

In this way, approximately 100,000 tonnes are produced annually. The reaction proceeds by the free radical process, involving the intermediacy of free chlorine atoms.^[4] Side products of the reaction include benzal chloride and benzotrichloride.

Other methods of production exist, such as the Blanc chloromethylation of benzene. Benzyl chloride was first prepared from treatment of benzyl alcohol with hydrochloric acid.

Uses and reactions[edit]

Industrially, benzyl chloride is the precursor to benzyl esters which are used as plasticizers, flavorants, and perfumes. Phenylacetic acid, a precursor to pharmaceuticals, is produced from benzyl cyanide, which is generated by treatment of benzyl chloride with sodium cyanide. Quaternary ammonium salts, used as surfactants, are readily formed by alkylation of tertiary amines with benzyl chloride.^[3]

In organic synthesis, benzyl chloride is used for the introduction of the benzyl protecting group in reaction with alcohols, yielding the corresponding benzyl ether, carboxylic acids, and benzyl ester. Benzoic acid (C₆H₅COOH) can be prepared by oxidation of benzyl chloride in the presence of alkaline KMnO₄:

C₆H₅CH₂Cl + 2 KOH + 2 [O] → C₆H₅COOK + KCl + H₂O

Benzyl chloride may be used in the synthesis of amphetamine-class drugs, and for this reason, sales of benzyl chloride are monitored as a List II drug precursor chemical by the US Drug Enforcement Administration.

Benzyl chloride also reacts readily with metallic magnesium to produce a Grignard Reagent.^[5] It is preferable over benzyl bromidefor the preparation of this reagent, since the reaction of the bromide with magnesium tends to form the Wurtz-coupling product 1,2-diphenylethane.

Safety[edit]

Benzyl chloride is an alkylating agent. Indicative of its high reactivity (relative to alkyl chlorides), benzyl chloride reacts with water in a hydrolysis reaction to form benzyl alcohol and hydrochloric acid. In contact with mucous membranes, hydrolysis produces hydrochloric acid. Thus, benzyl chloride is a lachrymator and has been used in chemical warfare. It is also very irritating to the skin.

It is classified as an extremely hazardous substance in the United States as defined in Section 302 of the U.S. Emergency Planning and Community Right-to-Know Act (42 U.S.C. 11002), and is subject to strict reporting requirements by facilities which produce, store, or use it in significant quantities.^[6]

See also[edit]

• Benzyl bromide
• Benzyl fluoride
• Benzyl iodide

References[edit]

1. ^ Jump up to:^{a b c d e f g} "NIOSH Pocket Guide to Chemical Hazards #0053". National Institute for Occupational Safety and Health (NIOSH).
2. ^ Jump up to:^a b "Benzyl chloride". Immediately Dangerous to Life and Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
3. ^ Jump up to:^a b "Chlorinated Hydrocarbons", Ullmann's Encyclopedia of Industrial Chemistry, Weinheim: Wiley-VCH, doi:10.1002/14356007.a06_233.pub2
4. Jump up^ Furniss, B. S.; Hannaford, A. J.; Smith, P. W. G.; Tatchell, A. R. (1989), Vogel's Textbook of Practical Organic Chemistry (5th ed.), Harlow: Longman, p. 864, ISBN 0-582-46236-3.
5. Jump up^ Henry Gilman and W. E. Catlin (1941). "n-Propylbenzene". Organic Syntheses.; Collective Volume, 1, p. 471
6. Jump up^ "40 C.F.R.: Appendix A to Part 355—The List of Extremely Hazardous Substances and Their Threshold Planning Quantities" (PDF) (July 1, 2008 ed.). Government Printing Office. Retrieved October 29, 2011.

External links[edit]

Wikimedia Commons has media related to Benzyl chloride.

• International Chemical Safety Card 0016
• SIDS Initial Assessment Report for benzyl chloride from the Organisation for Economic Co-operation and Development(OECD)
• CDC - NIOSH Pocket Guide for Chemical Hazards - Benzyl chloride

Authority control	GND: 4279968-5

Categories: 

• Organochlorides
• Lachrymatory agents
• IARC Group 2A carcinogens
• Benzyl compounds