4-Hydroxyphthalic acid → 5-Hydroxyisoindoline-1,3-dione

HRID 431580Notes

Reaction equation

HRID 431580 reaction equation
[OH:1][C:2]1[CH:3]=[C:4]([C:11]([OH:13])=O)[C:5](=[CH:9][CH:10]=1)[C:6](O)=[O:7].C(=O)([O-])[O-].[NH4+:18].[NH4+]>C(O)(=O)C>[OH:1][C:2]1[CH:3]=[C:4]2[C:5](=[CH:9][CH:10]=1)[C:6](=[O:7])[NH:18][C:11]2=[O:13]

Participants

4

Reactant 2

HCID 118814-Hydroxyphthalic acidHCID 517111Ammonium Carbonate

Product 1

HCID 105589505-Hydroxyisoindoline-1,3-dioneYield 72.7%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Conditions

Temperature
120 °C

Procedure

A mixture of 4-hydroxyphthalic acid (5.0 g, 27.0 mmol), acetic acid (25 mL), and ammonium carbonate (5.3 g, 55 mmol) was heated at 120° C. for 45 min followed by heating at 160° C. for 2 h. After cooling to room temperature, the reaction mixture was half-evaporated and then the reaction mixture was basified to pH 10 with 1 N NaOH followed by acidification to pH 5 at 0° C. with concentrated HCl. The resulting precipitate was filtered off, washed with water, dried at 60° C. under high vacuum over night, to afford the title compound (3.2 g, 71%) as an off-white crystalline solid. MS: m/e=162.1 (M−H+).

Workup

  1. temperatureby heating at 160° C. for 2 h
  2. temperatureAfter cooling to room temperature
  3. customthe reaction mixture was half-evaporated
  4. customfollowed by acidification to pH 5 at 0° C. with concentrated HCl
  5. filtrationThe resulting precipitate was filtered off
  6. washwashed with water
  7. customdried at 60° C. under high vacuum over night

Sources & evidence

ORD record
ord-16a949e644224a54bd8cb7fe11dcc440
Source dataset
uspto-grants-2003_12
Patent number
US06660736B2

Reaction notes

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