Acetyl chloride

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Acetyl chloride
Names
IUPAC name
Acetyl chloride
Preferred IUPAC name
Acetyl chloride
Systematic IUPAC name
Ethanoyl chloride
Other names
Acetic acid chloride
Acetic chloride
Properties
CH3COCl
Molar mass 78.49 g/mol
Appearance Colorless fuming liquid
Odor Pungent sharp
Density 1.104 g/cm3
Melting point −112 °C (−170 °F; 161 K)
Boiling point 52 °C (126 °F; 325 K)
Reacts
Solubility Miscible with glacial acetic acid, acetone, benzene, chloroform, diethyl ether, petroleum ether
Vapor pressure 287 mm Hg (25 °C)
Thermochemistry
Hazards
Safety data sheet Sigma-Aldrich
Flash point 4 °C
Related compounds
Related compounds
Acetic acid
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Acetyl chloride is an organic compound, an acyl chloride derived from acetic acid. It has the formula CH3COCl.

Properties

Chemical

Acetyl chloride will react with alcohols to yield esters and hydrogen chloride:

CH3COCl + CH2CH3OH → CH3-COO-CH2-CH3 + HCl

Physical

Acetyl chloride is a colorless fuming liquid, with a strong pungent sharp odor. It reacts with water, but soluble in many organic solvents.

Availability

Acetyl chloride is sold by chemical suppliers. However, due to its hazards, it is very difficult to acquire.

In some countries its sale is regulated as it can be used to make acetic anhydride, which is used for the manufacture of heroin.

Preparation

Acetyl chloride can be prepared through several ways.

An accessible route involves the reaction of glacial acetic acid and HCl. Dried HCl gas is bubbled through glacial acetic acid. The resulting product is fractionally distilled and the fraction with a close boiling point is collected and further purified. SM member Magpie was able to obtain crude acetyl chloride with a yield of 70% using this method.

Using acetic anhydride gives a better yield, though if you need acetic chloride for acetic anhydride, this route is not useful.

Reacting acetic acid with chlorodehydrating agents, such as phosgene, phosphorus trichloride, phosphorus pentachloride, thionyl chloride will also yield acetyl chloride. This is the most convenient route used in lab, but these compounds are difficult to obtain and are sensitive to water, making this route expensive.

Heating a mixture of benzoyl chloride with sodium acetate will give acetyl chloride.

Reaction of chlorine with solid acetaldehyde at -196.1 °C in the presence of UV light produces acetyl chloride, as well as oligomeric acetaldehyde as major reaction products. [2]

Reacting methyl chloride with carbon monoxide at 860 °C, in the presence of a catalyst, such as dry (NaPO3)6 or borax will give acetyl chloride.[3]

Another possible route involves reacting carbon tetrachloride with glacial acetic acid at 200 °C in the presence of several catalysts, such as MoO3-WO3, CuO-WO3, NiO-MoO3 or Al203-SiO2.[4]

One patent claims that one of the products from the hydrolysis of chloroform in the presence of iron(III) chloride, at temperatures between 150 - 160 °C is acetyl chloride. The process takes place at low pressure.[5]

Reaction of sulfuryl chloride with calcium acetate produces acetyl chloride.[6]

Projects

Handling

Safety

Acetyl chloride reacts with moisture to release fumes of hydrogen chloride which is very corrosive. Proper protection should be worn when handling the compound.

Storage

Acetyl chloride should be stored in air-tight containers in cool and well ventilated places. Schlenk flasks can also be used to store the compound.

Disposal

Acetyl chloride can be neutralized by slowly and carefully dissolving it in a basic solution then poured down the drain once fully neutralized.

References

  1. I.G. Farbenind.; Landolt-Boernstein E II 1651
  2. Mansueto, Edward S.; Wight, Charles A.; Journal of Physical Chemistry; vol. 96; nb. 3; (1992); p. 1502 - 1504
  3. US2062344
  4. US2700679
  5. US1870601
  6. DE151864

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