242845

Acetic anhydride

ACS reagent, ≥98.0%

• Synonym(s): Acetanhydride, Acetic acid anhydride, Acetyl acetate, Acetyl anhydride, Ethanoic anhydride
• Linear Formula: (CH₃CO)₂O
• CAS Number: 108-24-7
• Molecular Weight: 102.09
• Beilstein: 385737
• EC Number: 203-564-8
• MDL number: MFCD00008705
• UNSPSC Code: 12352100
• PubChem Substance ID: 24854587
• NACRES: NA.21

Properties

• grade: ACS reagent
• Quality Level: 200
• vapor density: 3.5 (vs air)
• vapor pressure: 10 mmHg ( 36 °C); 4 mmHg ( 20 °C)
• Assay: ≥98.0%
• form: liquid
• autoignition temp.: 629 °F
• expl. lim.: 10.3 %
• impurities: MnO₄^- reducers, passes test
• evapn. residue: ≤0.003%
• refractive index: n20/D 1.390 (lit.)
• bp: 138-140 °C (lit.)
• mp: −73 °C (lit.)
• solubility: H₂O: slightly soluble
• density: 1.08 g/mL (lit.)
• anion traces: chloride (Cl^-): ≤5 ppm; phosphate (PO₄^3-): ≤0.001%; sulfate (SO₄^2-): ≤5 ppm
• cation traces: Fe: ≤5 ppm; heavy metals: ≤2 ppm
• functional group: anhydride; ester
• SMILES string: CC(=O)OC(C)=O
• InChI: 1S/C4H6O3/c1-3(5)7-4(2)6/h1-2H3
• InChI key: WFDIJRYMOXRFFG-UHFFFAOYSA-N

Description

General description

Acetic anhydride is an organic solvent. On dissolution in water it undergoes solvolysis to afford acetic acid. It is widely employed for the acetylation of various alcohols. Wacher process (starting reagent + a ketene) and Knapsack process (starting reagent = acetaldehyde) have been reported for the industrial preparation of acetic anhydride.

Application

Acetic anhydride has been used as one of the reaction components in the preparation of:

• 2-acetylamino-5-aminobenzenesulfonic acid
• 3,3′-bis(sulfonato)-4,4′-bis(chloroacetamido)azobenzene (BSBCA)
• 10-acetoxy-9-nitro-octadecanoic acid, allyl ester
• 9-nitro-oleic acid

It may be used for acetylation of anisole over HBEA zeolite in a batch reactor.

Safety Information

• Pictograms: GHS02,GHS06,GHS05
• Signal Word: Danger
• Hazard Statements: H226,H302,H314,H330
• Precautionary Statements: P210 - P280 - P301 + P312 - P303 + P361 + P353 - P304 + P340 + P310 - P305 + P351 + P338
• Hazard Classifications: Acute Tox. 2 Inhalation - Acute Tox. 4 Oral - Eye Dam. 1 - Flam. Liq. 3 - Skin Corr. 1B
• Storage Class Code: 3 - Flammable liquids
• WGK: WGK 1
• Flash Point(F): 120.2 °F - closed cup
• Flash Point(C): 49 °C - closed cup
• Personal Protective Equipment: dust mask type N95 (US), Eyeshields, Gloves