p-Toluenesulfonic acid → Diethyl furo[2,3-b]pyridine-5,6-dicarboxylate

HRID 580292Notes

Reaction equation

HRID 580292 reaction equation
[C:1]([C:4]1[C:9](=[O:10])[NH:8][C:7]([C:11]([O:13][CH2:14][CH3:15])=[O:12])=[C:6]([C:16]([O:18][CH2:19][CH3:20])=[O:17])[CH:5]=1)(=O)[CH3:2].C1(C)C=CC(S(O)(=O)=O)=CC=1>C1(C)C(C)=CC=CC=1>[O:10]1[C:9]2=[N:8][C:7]([C:11]([O:13][CH2:14][CH3:15])=[O:12])=[C:6]([C:16]([O:18][CH2:19][CH3:20])=[O:17])[CH:5]=[C:4]2[CH:1]=[CH:2]1

Participants

4

Reactant 2

HCID 6101p-Toluenesulfonic acidHCID 13752508Diethyl 5-acetyl-1,6-dihydro-6-oxo-2,3-pyridinedicarboxylate

Product 1

HCID 13849598Diethyl furo[2,3-b]pyridine-5,6-dicarboxylate

Reagents, catalysts & solvents 1

HCID 7237O-XyleneSolvent

Procedure

A xylene solution of the hydroxy-furo compound obtained in Example 23, (3.7 g) containing paratoluene sulfonic acid (0.01 g) is heated at reflux for two hours. The solution is cooled and the xylene solution decanted off. The residue is extracted with ether and the extracts combined with the xylene. Distillation of the solvents gives a yellow solid which is crystallized from a cyclohexane-toluene mixture to give pure diethyl furo[2,3-b]pyridine-5,6-dicarboxylate mp 66°-77° C.

Workup

  1. temperatureis heated
  2. temperatureat reflux for two hours
  3. temperatureThe solution is cooled
  4. customthe xylene solution decanted off
  5. extractionThe residue is extracted with ether
  6. distillationDistillation of the solvents
  7. customgives a yellow solid which
  8. customis crystallized from a cyclohexane-toluene mixture

Sources & evidence

ORD record
ord-0f563451ac3a458abccff7c8877d36ee
Source dataset
uspto-grants-1988_06
Patent number
US04752323

Reaction notes

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