Acetic anhydride

Molecular Structure:

Molecular Formula: C₄H₆O₃
Molecular Weight: 102.09
IUPAC Name: Acetyl acetate
Synonyms of Acetic anhydride (CAS NO.108-24-7): Acetanhydride ; Acetic acid, anhydride ; Acetic oxide ; Acetyl acetate ; Anhydride acetique ; Anidride acetica ; Essigsaeureanhydrid ; Acetic acid, 1,1'-anhydride
CAS NO: 108-24-7
EINECS: 203-564-8
H bond acceptors: 3
H bond donors: 0
Freely Rotating Bonds: 2
Polar Surface Area: 43.37 Å²
Index of Refraction: 1.386
Molar Refractivity: 22.38 cm³
Molar Volume: 95.1 cm³
Surface Tension: 29.1 dyne/cm
Density: 1.072 g/cm³
Flash Point: 54.4 °C
Enthalpy of Vaporization: 37.83 kJ/mol
Boiling Point: 141.1 °C at 760 mmHg
Vapour Pressure: 5.94 mmHg at 25°C
Melting Point: -73.1 °C
Storage temp: Store at RT.
Water Solubility: REACTS
Sensitive: Moisture Sensitive
Stability: Stability Flammable. Incompatible with strong oxidizing agents, water, strong bases, alcohols.
Appearance: Colorless liquid
Product Categories of Acetic anhydride (CAS NO.108-24-7): Pharmaceutical Intermediates;Biochemistry;Reagents for Oligosaccharide Synthesis;Chemistry;Acylation ReagentsDerivatization Reagents GC;AminesDerivatization Reagents;GC Derivatization Reagents, by Application;Acylation ReagentsDerivatization Reagents;Analytical/Chromatography;Derivatization Reagents;Derivatization Reagents GC;Reagents for Acylation;ACS GradeOrganic Building Blocks;Carbonyl Compounds;Carboxylic Acid Anhydrides;Essential Chemicals;Routine Reagents;A-B, Puriss p.a. ACSDerivatization Reagents;Analytical Reagents for General Use;Derivatization Reagents HPLC;Puriss p.a. ACS;UV-VIS;A-B, Puriss p.a. ACSAnalytical/Chromatography;Reagent Plus;Alkaline β-eliminationFatty Acids;AnhydridesDeglycosylation Strategies;Reagent GradeProtein Modification;Reagents for lysine modification;Chemical Deglycosylation;Deglycosylation Strategies;HydrazinolysisEssential Chemicals;Saturated fatty acids and derivatives;Specific Amino Acid Modification

 Acetic anhydride (CAS NO.108-24-7) is mainly used for acetylations leading to commercially significant materials. It is mainly used for the conversion of cellulose to cellulose acetate, which is a component of photographic film and other coated materials. For the same reason  it is used in the production of aspirin, acetylsalicylic acid, which is prepared by the acetylation of salicylic acid. It is also used as a wood preservative via autoclave impregnation to make a longer lasting timber. In starch industry, Acetic anydride is a common acetylation compound, used for the production of modified starches.

  Acetic anhydride (CAS NO.108-24-7) may be produced by three different methods.
The first procedure involves the in situ production from acetaldehyde of peracetic acid, which in turn reacts with more acetaldehyde to yield the anhydride.
          CH₃CH=O + O₂ → CH₃C(=O)OH
  CH₃C(=O)OH + CH₃C=O → CH₃C(=O)O(O=)CCH₃ + H₂O
In the preferred process, acetic acid (or acetone) is pyrolyzed to ketene, which reacts with acetic acid to form acetic anhydride.
          CH₃C(=O)OH → CH₂=C=O + H₂O
    CH₂=C=O + CH₃C(=O)OH → CH₃C(=O)O(O=)CCH₃
Another process to make acetic anhydride involves carbon monoxide insertion into methyl acetate.
       CH₃C(=O)OCH₃ → CH₃C(=O)O(O=)CCH₃

Hazard Codes: C,Xn,F,Xi
Risk Statements: 10-11-19-34-41-37/38-20/21/22
R10: Flammable. 
R11: Highly flammable. 
R19: May form explosive peroxides. 
R34: Causes burns. 
R41: Risk of serious damage to the eyes. 
R37/38: Irritating to respiratory system and skin. 
R20/21/22: Harmful by inhalation, in contact with skin and if swallowed.
Safety Statements: 26-16-33-45-36/37/39
S16: Keep away from sources of ignition. 
S26: In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. 
S33: Take precautionary measures against static discharges.
S45: In case of accident or if you feel unwell, seek medical advice immediately (show the label whenever possible.) 
S36/37/39: Wear suitable protective clothing, gloves and eye/face protection.
RIDADR: UN 2924 3/PG 2
WGK Germany: 3
RTECS: AK1925000
F: 21
HazardClass: 8
PackingGroup: II
HS Code: 29152400