Iodine → Benzaldehyde, 4-hydroxy-3-iodo-5-methoxy-

HRID 358288

Reaction equation

HRID 358288 reaction equation
[O:1]=[CH:2][C:3]1[CH:11]=[CH:10][C:8]([OH:9])=[C:5]([O:6][CH3:7])[CH:4]=1.[Na+].[I-:13].OS(O)(=O)=O.II>[OH-].[Na+]>[I:13][C:10]1[C:8]([OH:9])=[C:5]([O:6][CH3:7])[CH:4]=[C:3]([CH:11]=1)[CH:2]=[O:1]

Participants

6

Reactant 4

HCID 807IodineHCID 1118Sulfuric Acid2×HCID 1183VanillinHCID 5238Sodium Iodide

Product 1

HCID 79499Benzaldehyde, 4-hydroxy-3-iodo-5-methoxy-Yield 99%

Reagents, catalysts & solvents 1

HCID 14798Sodium HydroxideSolvent

Conditions

Temperature
90 °C

Procedure

Vanillin (28.4 g, 200 mmole (millimole)) was dissolved in 1N NaOH (200 ml) and warmed to 90° C. to avoid precipitation of sodium vanillate. A 2 molar aqueous solution of NaI3.NaI (105 ml, 210 mmole I2) plus 3.55 molar aqueous H2SO4 (5 ml) was added over 3 hours with stirring. The iodine color was discharged, and a pale tan stirrable precipitate formed. The solution was then cooled to room temperature, acidified to pH 2-3 with 20% aqueous H2SO4, and extracted with 10% methanol/90% chloroform. The organic phase was dried (MgSO4) and the solvent stripped to yield 53 g (99%) of 5-iodovanillin, more than 95% pure as analyzed by nuclear magnetic resonance spectroscopy (NMR).

Workup

  1. customprecipitation of sodium vanillate
  2. customa pale tan stirrable precipitate formed
  3. temperatureThe solution was then cooled to room temperature
  4. extractionextracted with 10% methanol/90% chloroform
  5. dry with materialThe organic phase was dried (MgSO4)

Sources & evidence

ORD record
ord-b93f7d28983548e283afb2b789cd9b20
Source dataset
uspto-grants-1984_08
Patent number
US04465864

Linked notes

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