Salicylic Acid → Aspirin

HRID 1985001Notes

Reaction equation

HRID 1985001 reaction equation
[C:1]([OH:10])(=[O:9])[C:2]1[C:3](=[CH:5][CH:6]=[CH:7][CH:8]=1)[OH:4].[C:11](OC(=O)C)(=[O:13])[CH3:12]>COC1C=CC(C2OC(C3C=CC(OC)=C(OC)C=3)CCC2)=CC=1OC>[C:11]([O:4][C:3]1[C:2](=[CH:8][CH:7]=[CH:6][CH:5]=1)[C:1]([OH:10])=[O:9])(=[O:13])[CH3:12]

Participants

4

Reactant 2

HCID 338Salicylic Acid2×HCID 7918Acetic Anhydride

Product 1

HCID 2244Aspirin

Reagents, catalysts & solvents 1

HCID 1325512,6-Bis(3,4-dimethoxyphenyl)oxaneCatalyst

Conditions

Temperature
120 °C

Procedure

0.0072 moles of salicylic acid and 0.029 moles acetic anhydride (molar ratio=1:4) were taken in a 20 ml reaction vessel of reaction station. Nano-crystalline sulfated zirconia catalyst (SZ-1), activated at 450° C. in static air with salicylic acid to catalyst weight ratio 10:1, was added and the mixture was heated at 120° C. for 30 minutes. The reaction mixture was filtered to separate the catalyst. The acetyl salicylic acid was crystallized from the reaction mixture. The crude yield of acetyl salicylic acid was 92-95%. It was further re-crystallized with ethanol-water to obtain pure crystals of acetyl salicylic acid.

Workup

  1. additionwas added
  2. filtrationThe reaction mixture was filtered
  3. customto separate the catalyst
  4. customThe acetyl salicylic acid was crystallized from the reaction mixture
  5. customIt was further re-crystallized with ethanol-water

Sources & evidence

ORD record
ord-184b1396a1934ae0bc29ec3e24327dec
Source dataset
uspto-grants-2009_06
Patent number
US07544831B2

Reaction notes

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