Acetic Anhydride → 5-Acetoxyisophthalic Acid

HRID 1614279Notes

Reaction equation

HRID 1614279 reaction equation
[OH:1][C:2]1[CH:3]=[C:4]([C:11]([OH:13])=[O:12])[CH:5]=[C:6]([CH:10]=1)[C:7]([OH:9])=[O:8].[C:14](OC(=O)C)(=[O:16])[CH3:15]>>[C:14]([O:1][C:2]1[CH:3]=[C:4]([C:11]([OH:13])=[O:12])[CH:5]=[C:6]([CH:10]=1)[C:7]([OH:9])=[O:8])(=[O:16])[CH3:15]

Participants

3

Reactant 2

HCID 7918Acetic AnhydrideHCID 692575-Hydroxyisophthalic acid

Product 1

HCID 109221485-Acetoxyisophthalic Acid

Procedure

5-hydroxyisophthalic acid (45.5 grams, 0.25 mole) was heated in acetic acid anhydride (102 grams, 1 mole) to reflux for one-half hour until dissolved. Refluxing was continued for a total time of 5 hours. Excess acetic acid anhydride was removed in vacuum and white product was recrystallized twice from a chloroform/toluene (50/50 weight/weight) mixture. Yield was 48 grams, which was 86% of theoretical yield. A melting point was determined, as in all of the preparations and examples using a Thomas-Hoover melting point apparatus, which indicated onset of decomposition, and apparent release of acetic acid, at a temperature of about 235° C. Nuclear magnetic resonance (NMR) performed on a 300 MHz GE instrument using deuterated dimethylsulfoxide (DMSO-d6) gave the following peaks (in parts per million (ppm)): 2.25 (s,3H), 7.8 (s,2H), 8.3 (s,1H),13.4 (broad, 2H, COOH).

Workup

  1. temperatureto reflux for one-half hour
  2. dissolutionuntil dissolved
  3. temperatureRefluxing
  4. customwas continued for a total time of 5 hours
  5. customExcess acetic acid anhydride was removed in vacuum and white product
  6. customwas recrystallized twice from a chloroform/toluene (50/50 weight/weight) mixture
  7. customat a temperature of about 235° C
  8. customgave the following peaks (in parts per million (ppm))

Sources & evidence

ORD record
ord-157641235d6a4b33bced54b12f4cc103
Source dataset
uspto-grants-1993_03
Patent number
US05196502

Reaction notes

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