Sulfuric Acid → Syringaldehyde

HRID 394418Notes

Reaction equation

HRID 394418 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]([CH:8]=[C:9]([O:13][CH3:14])[C:10]=1[O:11]C)[CH:6]=[O:7].S(=O)(=O)(O)O>>[CH3:14][O:13][C:9]1[CH:8]=[C:5]([CH:4]=[C:3]([O:2][CH3:1])[C:10]=1[OH:11])[CH:6]=[O:7]

Participants

3

Reactant 2

HCID 1118Sulfuric AcidHCID 68583,4,5-Trimethoxybenzaldehyde

Product 1

HCID 8655Syringaldehyde

Procedure

Monodemethylation of 3,4,5-trimethoxy benzaldehyde using sulphuric acid at 40° C. for 8 hours yields 3,5-Dimethoxy-4-hydroxy benzaldehyde (Syringaldehyde). Condensation of syringaldehyde with ethyl cyanoacetate in the presence of piperidine—acetic acid and benzene as the reaction medium at reflux temperature under continuous azeotropic water removal yields the title product. The reaction takes about 1.5 hours for completion. The yield obtained is typically 95%.

Workup

  1. customat 40° C.
  2. customfor 8 hours

Sources & evidence

ORD record
ord-2c30a265a15946deb2c3af6cb2cd1968
Source dataset
uspto-grants-2003_08
Patent number
US06602515B2

Reaction notes

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