Sulfuric Acid → Syringaldehyde

HRID 394420Notes

Reaction equation

HRID 394420 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>>[CH:6](=[O:7])[C:5]1[CH:4]=[C:3]([O:2][CH3:1])[C:10]([OH:11])=[C:9]([O:13][CH3:14])[CH:8]=1

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 as described above in Example 1 yields syringaldehyde. The Wittig salt is prepared by reaction of triphenyl phosphine and ethyl-2-bromopropionate in benzene media at 70-75 ° C. for 8 hours and subsequent basification with 1N Sodium hydroxide to phenolphthalein end point at room temperature. Extraction with benzene, concentration of the benzene extract and the addition of petroleum ether (60-80° C.) yield triphenyl methyl carbethoxy methylene phosphorane as a solid product. Condensation of 3,5-Dimethoxy-4-hydroxy benzaldehyde (Syringaldehyde) with triphenyl methyl carbethoxy methylene phosphorane is performed at reflux temperature in xylene for seven hours and after work up, yields the title compound.

Workup

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

Sources & evidence

ORD record
ord-042e3d7d66764d1290d4c959010c034e
Source dataset
uspto-grants-2003_08
Patent number
US06602515B2

Reaction notes

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