Boron Trichloride → 2,3-Dihydroxy-4-methylbenzaldehyde

HRID 2368004Notes

Reaction equation

HRID 2368004 reaction equation
CO[C:3]1[CH:8]=[CH:7][CH:6]=[C:5]([CH3:9])[C:4]=1[O:10]C.[C:12](=[O:14])=O.CC(C)=[O:17].B(Cl)(Cl)Cl>ClCCl>[OH:17][C:9]1[C:12]([OH:14])=[C:8]([CH3:3])[CH:7]=[CH:6][C:5]=1[CH:4]=[O:10]

Participants

5

Reactant 3

HCID 25135Boron TrichlorideHCID 782153-MethylveratroleHCID 18522661Acetone cardice

Product 1

HCID 537336632,3-Dihydroxy-4-methylbenzaldehyde

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a solution of 1,2-dimethoxy-3-methyl-benzene (13.8 g, 76.66 mmol) cooled to −30° C. (dry ice/acetone) in dichloromethane (200 mL) was added boron trichloride (230 mL, 230 mmol) dropwise and the mixture was left to stir overnight at room temperature. The solution was cooled to 0° C. and ice/water was added carefully, and then extracted with excess of dichloromethane. The organic layer was washed with water, dried (Na2SO4) and the solvent was evaporated. Purification by silica gel column chromatography (10-20% EtOAc/hexane) gave the title compound as a crystalline solid: yield 9.2 g (80%). 1H NMR (400 MHz, CDCl3) δ (ppm): 11.11 (s, 1H), 9.82 (s, 1H), 7.05 (d, J=8.2 Hz, 1H), 6.81 (d, J=8.6 Hz, 1H), 5.67 (s, 1H), 2.33 (s, 3H).

Workup

  1. waitthe mixture was left
  2. temperatureThe solution was cooled to 0° C.
  3. extractionextracted with excess of dichloromethane
  4. washThe organic layer was washed with water
  5. dry with materialdried (Na2SO4)
  6. customthe solvent was evaporated
  7. customPurification by silica gel column chromatography (10-20% EtOAc/hexane)

Sources & evidence

ORD record
ord-b6ef99f27c3a460593dc87dfaa9c1fed
Source dataset
uspto-grants-2014_04
Patent number
US08703742B2

Reaction notes

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