Cinchomeronic acid → 1H,3H-furo(3,4-c)pyridine-1,3-dione

HRID 52403

Reaction equation

HRID 52403 reaction equation
[N:1]1[CH:6]=[CH:5][C:4]([C:7]([OH:9])=O)=[C:3]([C:10]([OH:12])=[O:11])[CH:2]=1>C(OC(=O)C)(=O)C>[N:1]1[CH:6]=[CH:5][C:4]2[C:7]([O:12][C:10](=[O:11])[C:3]=2[CH:2]=1)=[O:9]

Participants

3

Reactant 1

HCID 10273Cinchomeronic acid

Product 1

HCID 2783981H,3H-furo(3,4-c)pyridine-1,3-dioneYield 76.2%

Reagents, catalysts & solvents 1

HCID 7918Acetic AnhydrideSolvent

Conditions

Temperature
70 °C

Procedure

Under nitrogen atmosphere a suspension of a 97% pure 3,4-pyridine dicarboxylic acid (152 g, 0.88 mol) in acetic anhydride (450 mL) was heated to reflux and a complete solution was obtained. Once refluxing temperature was reached, solvent was removed by distillation at atmospheric pressure (about 400 mL were collected) over a period of about 1 hour. Vapors temperature was observed to increase from about 132° C. to 140° C. and distillation was stopped when internal temperature reached 150°-155° C. The reaction mixture was cooled to 70° C. and tert-BuOMe (450 mL) was added dropwise under stirring. A dark grey solid precipitated at about 40° C. while temperature was spontaneously let reach 20°-25° C. The suspension was further cooled to 0°-5° C. and stirred for two hours. Under nitrogen blanket the dark grey precipitate was collected by filtration, washed with tert-BuOMe (100 mL) and dried under vacuum (20 torr; 30° C.; 2 h) to yield 3,4-pyridine dicarboxylic acid anhydride (100 g; yield 76%) which was directly used in the next step.

Workup

  1. temperaturewas heated
  2. temperatureto reflux
  3. customa complete solution was obtained
  4. temperatureOnce refluxing temperature
  5. customsolvent was removed by distillation at atmospheric pressure (about 400 mL were collected) over a period of about 1 hour
  6. temperatureto increase from about 132° C. to 140° C.
  7. distillationdistillation
  8. customreached 150°-155° C
  9. additiontert-BuOMe (450 mL) was added dropwise
  10. customA dark grey solid precipitated at about 40° C. while temperature
  11. customwas spontaneously let reach 20°-25° C
  12. temperatureThe suspension was further cooled to 0°-5° C.
  13. stirringstirred for two hours
  14. filtrationUnder nitrogen blanket the dark grey precipitate was collected by filtration
  15. washwashed with tert-BuOMe (100 mL)
  16. customdried under vacuum (20 torr; 30° C.; 2 h)

Sources & evidence

ORD record
ord-ff10d08336ce4e44ad5846a27b4f0a9e
Source dataset
uspto-grants-1997_04
Patent number
US05616709

Linked notes

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