Water → Thieno[2,3-b]pyridine-5,6-dicarboxylic acid

HRID 2073968Notes

Reaction equation

HRID 2073968 reaction equation
[S:1]1[C:5]2=[N:6][C:7]([C:14]([O:16]C)=[O:15])=[C:8]([C:10]([O:12]C)=[O:11])[CH:9]=[C:4]2[CH:3]=[CH:2]1.[OH-].[K+].O>CO>[S:1]1[C:5]2=[N:6][C:7]([C:14]([OH:16])=[O:15])=[C:8]([C:10]([OH:12])=[O:11])[CH:9]=[C:4]2[CH:3]=[CH:2]1

Participants

5

Reactant 3

HCID 962WaterHCID 14797Potassium HydroxideHCID 13729652Dimethyl thieno[2,3-b]pyridine-5,6-dicarboxylate

Product 1

HCID 13729663Thieno[2,3-b]pyridine-5,6-dicarboxylic acid

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A solution containing dimethyl thieno[2,3-b]-pyridine-5,6-dicarboxylate (27.75 g, 0.11 mol) and potassium hydroxide (30.98 g, 0.55 mol) in methanol (200 mL) under a N2 atmosphere is heated at reflux for two hours. The reaction mixture is cooled and sufficient water added to dissolve any solids present before evaporating the mixture to dryness. The resulting solid is dissolved in a minimum volume of water, cooled in an ice bath and acidified with concentrated H2SO4 to pH~1. Thieno[2,3-b]pyridine-5,6-dicarboxylic acid is filtered off and dried overnight to give 23.36 g mp 272°-275° C.

Workup

  1. temperatureis heated
  2. temperatureat reflux for two hours
  3. temperatureThe reaction mixture is cooled
  4. dissolutionto dissolve any solids present
  5. custombefore evaporating the mixture to dryness
  6. dissolutionThe resulting solid is dissolved in a minimum volume of water
  7. temperaturecooled in an ice bath
  8. filtrationThieno[2,3-b]pyridine-5,6-dicarboxylic acid is filtered off
  9. customdried overnight
  10. customto give 23.36 g mp 272°-275° C.

Sources & evidence

ORD record
ord-71216a25dd56440aaf259fa02201ae3e
Source dataset
uspto-grants-1990_04
Patent number
US04920226

Reaction notes

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