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

HRID 1449463Notes

Reaction equation

HRID 1449463 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. customis recrystallized from isopropanol
  7. customto give a melting point 71°-72° C.

Sources & evidence

ORD record
ord-50316797693349f6b67f215f2b6b1974
Source dataset
uspto-grants-1997_02
Patent number
US05599772

Reaction notes

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