|Systematic IUPAC name
|Jmol 3D model||Interactive image|
|Molar mass||78.49 g/mol|
|Density||1.104 g/ml, liquid|
|Melting point||−112 °C (−170 °F; 161 K)|
|Boiling point||52 °C (126 °F; 325 K)|
|Reacts with water|
EU classification (DSD)
|R-phrases||R11 R14 R34|
|S-phrases||(S1/2) S9 S16 S26 S45|
|Flash point||4 °C (39 °F; 277 K)|
|390 °C (734 °F; 663 K)|
Related acyl chlorides
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|what is ?)(|
- (CH3CO)2O + HCl → CH3COCl + CH3CO2H
Acetyl chloride is produced in the laboratory by the reaction of acetic acid with chlorodehydrating agents such as PCl3, PCl5, SO2Cl2, or SOCl2. However, these methods usually gives acetyl chloride contaminated by phosphorus or sulfur impurities, which may interfere with the organic reactions. a route avoiding these impurities of phosphorus and sulphur is that of phosgene and acetic acid, COCl2 + CH3COOH = CH3COCl + HCl + CO2. HCl impurities can be removed by distilling the crude product from dimethylaniline or by degassing the mixture by a stream of argon.
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.
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
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.
- Merck Index, 11th Edition, 79.
- 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.
- Hosea Cheung, Robin S. Tanke, G. Paul Torrence “Acetic Acid” in Ullmann's Encyclopedia of Industrial Chemistry, 2002, Wiley-VCH, Weinheim. doi:10.1002/14356007.a01_045
- 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
- Charles Merritt, Jr and Charles E. Braun "9-Acetylanthracene" Org. Synth. 1950, 30, 2. doi:10.15227/orgsyn.030.0001