Cornforth reagent → 5,6,7-Trimethoxynaphthalene-2-carbaldehyde

HRID 1267650Notes

Reaction equation

HRID 1267650 reaction equation
[OH:1][CH2:2][C:3]1[CH:12]=[CH:11][C:10]2[C:5](=[CH:6][C:7]([O:17][CH3:18])=[C:8]([O:15][CH3:16])[C:9]=2[O:13][CH3:14])[CH:4]=1.[Cr](O[Cr]([O-])(=O)=O)([O-])(=O)=O.[NH+]1C=CC=CC=1.[NH+]1C=CC=CC=1>ClCCl>[CH3:14][O:13][C:9]1[C:8]([O:15][CH3:16])=[C:7]([O:17][CH3:18])[CH:6]=[C:5]2[C:10]=1[CH:11]=[CH:12][C:3]([CH:2]=[O:1])=[CH:4]2

Participants

4

Reactant 2

HCID 2724130Cornforth reagentHCID 218915782-Hydroxymethyl-5,6,7-trimethoxynaphthalene

Product 1

HCID 218916375,6,7-Trimethoxynaphthalene-2-carbaldehyde

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

2-Hydroxymethyl-5,6,7-trimethoxynaphthalene (3.78 g) was dissolved in dichloromethane (100 mL), pyridinium dichromate (8. 61 g) was added to the solution, and the mixture was stirred at room temperature for 4 hours. The reaction mixture was filtered, and insoluble matter was washed with chloroform. After the filtrate was concentrated under reduced pressure, the residue was diluted with ethyl acetate, washed with 2 M hydrochloric acid, water and saturated brine, dried over anhydrous magnesium sulfate and then concentrated under reduced pressure. The residue was purified by column chromatography on silica gel (ethyl acetate:hexane=1:3 to 1:1) and further recrystallized from ethyl acetate-hexane to obtain the title compound.

Workup

  1. filtrationThe reaction mixture was filtered
  2. washinsoluble matter was washed with chloroform
  3. concentrationAfter the filtrate was concentrated under reduced pressure
  4. additionthe residue was diluted with ethyl acetate
  5. washwashed with 2 M hydrochloric acid, water and saturated brine
  6. dry with materialdried over anhydrous magnesium sulfate
  7. concentrationconcentrated under reduced pressure
  8. customThe residue was purified by column chromatography on silica gel (ethyl acetate:hexane=1:3 to 1:1)
  9. customfurther recrystallized from ethyl acetate-hexane

Sources & evidence

ORD record
ord-363d4181cdb6417a8a06e582fcaa39bc
Source dataset
uspto-grants-2003_04
Patent number
US06552188B2

Reaction notes

Loading…