Hydrochloric Acid → 5-(4-Formylbenzylidene)-2,4-thiazolidinedione

HRID 1281110Notes

Reaction equation

HRID 1281110 reaction equation
CCO[CH:4](OCC)[C:5]1[CH:10]=[CH:9][C:8]([CH:11]=[O:12])=[CH:7][CH:6]=1.[S:16]1[CH2:20][C:19](=[O:21])[NH:18][C:17]1=[O:22].N1CCCCC1.Cl>C(O)C>[CH:11]([C:8]1[CH:7]=[CH:6][C:5]([CH:4]=[C:20]2[S:16][C:17](=[O:22])[NH:18][C:19]2=[O:21])=[CH:10][CH:9]=1)=[O:12]

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 5437ThiazolidinedioneHCID 8082PiperidineHCID 5959934-(Diethoxymethyl)benzaldehyde

Product 1

HCID 32727725-(4-Formylbenzylidene)-2,4-thiazolidinedioneYield 94%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

To a mixture of terephthalaldehyde mono-(diethyl acetal) (3.96 mL, 20.0 mmol) and 2,4-thiazolidinedione (2.81 g, 24.0 mmol) in ethanol (40 mL) was added piperidine (2.0 mL, 20.0 mmol). The reaction mixture was heated to reflux for 4 h. After cooling on an ice-bath, hydrochloric acid (0.2 mol/L, 100 mL) was added and the precipitated products were collected by filtration. The cake was washed with water and dried. To a solution of this product (5.50 g) in tetrahydrofuran (180 mL) was added hydrochloric acid (1 mol/L, 18 mL) and the mixture was stirred at room temperature for 2 h. Water was added, and the precipitated products were collected by filtration to give 5-(4-formylbenzylidene)-2,4-thiazolidinedione (3.91 g, 94%).

Workup

  1. temperatureThe reaction mixture was heated
  2. temperatureto reflux for 4 h
  3. temperatureAfter cooling on an ice-bath
  4. filtrationthe precipitated products were collected by filtration
  5. washThe cake was washed with water
  6. customdried
  7. additionTo a solution of this product (5.50 g) in tetrahydrofuran (180 mL) was added hydrochloric acid (1 mol/L, 18 mL)
  8. additionWater was added
  9. filtrationthe precipitated products were collected by filtration

Sources & evidence

ORD record
ord-00d6190d86bf45d49634465ea5675c6c
Source dataset
uspto-grants-2002_09
Patent number
US06452014B1

Reaction notes

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