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

HRID 78301Notes

Reaction equation

HRID 78301 reaction equation
C(=O)([O-])[O-].[NH4+:5].[NH4+].[OH:7][C:8]1[CH:9]=[C:10]([C:17]([OH:19])=O)[C:11](=[CH:15][CH:16]=1)[C:12](O)=[O:13]>CC(O)=O>[OH:7][C:8]1[CH:9]=[C:10]2[C:11](=[CH:15][CH:16]=1)[C:12](=[O:13])[NH:5][C:17]2=[O:19]

Participants

4

Reactant 2

HCID 118814-Hydroxyphthalic acidHCID 517111Ammonium Carbonate

Product 1

HCID 105589505-Hydroxyisoindoline-1,3-dione

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Conditions

Temperature
120 °C

Procedure

To a mixture of ammonium carbonate (5.28 g, 54.9 mmol) in conc. AcOH (25 mL) was slowly added 4-hydroxyphthalic acid (5.0 g, 27.45 mmol). The resulting mixture was heated at 120° C. for 45 min., then the clear, bright yellow mixture was heated at 160° C. for 2 h. The resulting mixture was maintained at 160° C. and was concentrated to approximately 15 mL, then was cooled to room temp. and adjusted pH 10 with a 1N NaOH solution. This mixture was cooled to 0° C. and slowly acidified to pH 5 using a 1N HCl solution. The resultant precipitate was collected by filtration and dried under reduced pressure to yield 5-hydroxyisoindoline-1,3-dione as a pale yellow powder as product (3.24 g, 72%): 1H NMR (DMSO-d6) δ 7.00-7.03 (m, 2H), 7.56 (d, J=9.3 Hz, 1H).

Workup

  1. temperaturethe clear, bright yellow mixture was heated at 160° C. for 2 h
  2. temperatureThe resulting mixture was maintained at 160° C.
  3. concentrationwas concentrated to approximately 15 mL
  4. temperaturewas cooled to room temp.
  5. temperatureThis mixture was cooled to 0° C.
  6. filtrationThe resultant precipitate was collected by filtration
  7. customdried under reduced pressure

Sources & evidence

ORD record
ord-399762f413994fe98934a9d52c198ff6
Source dataset
uspto-grants-2014_09
Patent number
US08841330B2

Reaction notes

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