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

HRID 52403

反応式

HRID 52403 の反応式
[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]

参加物

3

反応条件

温度
70 °C

実験手順

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.

後処理

  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)

出典と根拠

ORDレコード
ord-ff10d08336ce4e44ad5846a27b4f0a9e
出典データセット
uspto-grants-1997_04
特許番号
US05616709

関連ノート

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