p-Toluenesulfonic acid → diethyl 4-oxo-4H-pyrano[2,3-b]pyridine-6,7-dicarboxylate

HRID 864932Notes

Reaction equation

HRID 864932 reaction equation
CN(C)[CH:3]=[CH:4][C:5]([C:7]1[C:12](=[O:13])[NH:11][C:10]([C:14]([O:16][CH2:17][CH3:18])=[O:15])=[C:9]([C:19]([O:21][CH2:22][CH3:23])=[O:20])[CH:8]=1)=[O:6].C1(C)C=CC(S(O)(=O)=O)=CC=1>C(O)(=O)C>[O:6]=[C:5]1[C:7]2[C:12](=[N:11][C:10]([C:14]([O:16][CH2:17][CH3:18])=[O:15])=[C:9]([C:19]([O:21][CH2:22][CH3:23])=[O:20])[CH:8]=2)[O:13][CH:3]=[CH:4]1

Participants

4

Reactant 2

HCID 6101p-Toluenesulfonic acidHCID 53835628Diethyl 5-[3-(dimethylamino)acryloyl]1,6-dihydro-6-oxo-2,3-pyridinedicarboxylate

Product 1

HCID 19958243diethyl 4-oxo-4H-pyrano[2,3-b]pyridine-6,7-dicarboxylate

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

Diethyl 5-[3-(dimethylamino)acryloyl]-1,6-dihydro-6-oxo-2,3-pyridinedicarboxylate (6 g, 0.0178 mol), and p-toluenesulfonic acid (4.5 g, 0.021 mol) in acetic acid (60 mL) are heated at reflux for three hours. The mixture is then evaporated to dryness, neutralized with a saturated NaHCO3 solution and extracted with methylene chloride. The organic solution is dried over Na2SO4, and concentrated to a thick oil, which solidifies after trituration with hexane-ether (4 g, 77%). The product is recrystallized from isopropanol to give a melting point 71°-72° C.

Workup

  1. temperatureat reflux for three hours
  2. customThe mixture is then evaporated to dryness
  3. extractionextracted with methylene chloride
  4. dry with materialThe organic solution is dried over Na2SO4
  5. concentrationconcentrated to a thick oil, which
  6. customThe product is recrystallized from isopropanol
  7. customto give a melting point 71°-72° C.

Sources & evidence

ORD record
ord-7520cf644ac0482f89182c9b8bb9e12f
Source dataset
uspto-grants-1996_10
Patent number
US05565412

Reaction notes

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