Acetyl chloride - Misplaced Pages

(Redirected from AcCl) Organic compound (CH₃COCl) Not to be confused with Chloroacetic acid, Chloroacetyl chloride, Acetylcholine, or Actinium(III) chloride.

Acetyl chloride

Names

Preferred IUPAC name Acetyl chloride

Systematic IUPAC name Ethanoyl chloride

Other names Acyl chloride

Identifiers

CAS Number

75-36-5

3D model (JSmol)

Interactive image

Beilstein Reference

605303

ChEBI

CHEBI:37580

ChemSpider

6127

DrugBank

DB14623

ECHA InfoCard

100.000.787

EC Number

200-865-6

Gmelin Reference

1611

PubChem CID

6367

RTECS number

AO6390000

UNII

QD15RNO45K

UN number

1717

CompTox Dashboard (EPA)

DTXSID2023852

InChI

InChI=1S/C2H3ClO/c1-2(3)4/h1H3Key: WETWJCDKMRHUPV-UHFFFAOYSA-N
InChI=1/C2H3ClO/c1-2(3)4/h1H3Key: WETWJCDKMRHUPV-UHFFFAOYAQ

SMILES

ClC(=O)C

Properties

Chemical formula

CH₃COCl

Molar mass

78.49 g/mol

Appearance

Colorless liquid

Density

1.104 g/ml, liquid

Melting point

−112 °C (−170 °F; 161 K)

Boiling point

52 °C (126 °F; 325 K)

Solubility in water

Reacts with water

Magnetic susceptibility (χ)

-38.9·10 cm/mol

Structure

Dipole moment

2.45 D

Hazards

GHS labelling:

Pictograms

Signal word

Danger

Hazard statements

H225, H302, H314, H335, H412

Precautionary statements

P210, P233, P240, P241, P242, P243, P260, P261, P264, P270, P271, P273, P280, P301+P312, P301+P330+P331, P303+P361+P353, P304+P340, P305+P351+P338, P310, P312, P321, P330, P363, P370+P378, P403+P233, P403+P235, P405, P501

NFPA 704 (fire diamond)

3 3 2 W

Flash point

4 °C (39 °F; 277 K)

Autoignition
temperature

390 °C (734 °F; 663 K)

Explosive limits

7.3–19%

Related compounds

Related acyl chlorides

Propionyl chloride
Butyryl chloride

Related compounds

Acetic acid
Acetic anhydride
Acetyl bromide

Except where otherwise noted, data are given for materials in their standard state (at 25 °C , 100 kPa).

Y verify (what is ?) Infobox references

Chemical compound

Acetyl chloride (CH₃COCl) is an acyl chloride derived from acetic acid (CH₃COOH). It belongs to the class of organic compounds called acid halides. It is a colorless, corrosive, volatile liquid. Its formula is commonly abbreviated to AcCl.

Synthesis

On an industrial scale, the reaction of acetic anhydride with hydrogen chloride produces a mixture of acetyl chloride and acetic acid:

(CH₃CO)₂O + HCl → CH₃COCl + CH₃CO₂H

Laboratory routes

Acetyl chloride was first prepared in 1852 by French chemist Charles Gerhardt by treating potassium acetate with phosphoryl chloride.

Acetyl chloride is produced in the laboratory by the reaction of acetic acid with chlorodehydrating agents such as phosphorus trichloride (PCl₃), phosphorus pentachloride (PCl₅), sulfuryl chloride (SO₂Cl₂), phosgene, or thionyl chloride (SOCl₂). However, these methods usually give acetyl chloride contaminated by phosphorus or sulfur impurities, which may interfere with the organic reactions.

Other methods

When heated, a mixture of dichloroacetyl chloride and acetic acid gives acetyl chloride. It can also be synthesized from the catalytic carbonylation of methyl chloride.

Occurrence

Acetyl chloride is not expected to exist in nature, because contact with water would hydrolyze it into acetic acid and hydrogen chloride. In fact, if handled in open air it releases white "smoke" resulting from hydrolysis due to the moisture in the air. The smoke is actually small droplets of hydrochloric acid and acetic acid formed by hydrolysis.

Uses

Acetyl chloride is used for acetylation reactions, i.e., the introduction of an acetyl group. Acetyl is an acyl group having the formula −C(=O)−CH₃. For further information on the types of chemical reactions compounds such as acetyl chloride can undergo, see acyl halide. Two major classes of acetylations include esterification and the Friedel-Crafts reaction.

Acetic acid esters and amide

Acetyl chloride is a reagent for the preparation of esters and amides of acetic acid, used in the derivatization of alcohols and amines. One class of acetylation reactions are esterification, for example the reaction with ethanol to produce ethyl acetate and hydrogen chloride:

CH₃COCl + HO−CH₂−CH₃ → CH₃−COO−CH₂−CH₃ + HCl

Frequently such acylations are carried out in the presence of a base such as pyridine, triethylamine, or DMAP, which act as catalysts to help promote the reaction and as bases neutralize the resulting HCl. Such reactions will often proceed via ketene.

Friedel-Crafts acetylations

A second major class of acetylation reactions are the Friedel-Crafts reactions.

References

Merck Index, 11th Edition, 79.
Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. 2014. pp. 796–797. doi:10.1039/9781849733069-FP001. ISBN 978-0-85404-182-4.
Cheung, Hosea; Tanke, Robin S.; Torrence, G. Paul (2000). "Acetic Acid". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a01_045. ISBN 3527306730.
See:
- Gerhardt, Charles (1852) "Ueber wasserfreie organische Säuren" (On anhydrous organic acids), Annalen der Chemie und Pharmacie, 83 : 112–116.
- Gerhardt, Charles (1853) "Untersuchungen über die wasserfreien organischen Säuren" (Investigations into anhydrous organic acids), Annalen der Chemie und Pharmacie, 87 : 57–84; see especially pp. 68–71.
^ Leo A. Paquette (2005). "Acetyl chloride". Handbook of Reagents for Organic Synthesis, Activating Agents and Protective Groups. John Wiley & Sons. p. 16. ISBN 978-0-471-97927-2.
US 4352761, Erpenbach, Heinz; Gehrmann, Klaus & Lork, Winfried et al., "Production of acetyl chloride", published 1982-10-05, assigned to Hoechst AG
Charles Merritt, Jr and Charles E. Braun "9-Acetylanthracene" Org. Synth. 1950, 30, 2. doi:10.15227/orgsyn.030.0001