HCID 13443700, compound → HCID 10751406, compound

HRID 2260369Notes

Reaction equation

HRID 2260369 reaction equation
[CH3:1][O:2][C:3]1[C:4](=[O:16])[C:5]2[C:10]([C:11](=[O:13])[CH:12]=1)=[CH:9][C:8]([CH3:14])=[C:7]([CH3:15])[CH:6]=2>O>[CH3:14][CH:8]1[CH:7]([CH3:15])[CH2:6][C:5]2[C:4](=[O:16])[C:3]([O:2][CH3:1])=[CH:12][C:11](=[O:13])[C:10]=2[CH2:9]1

Participants

3

Reactant 1

HCID 13443700HCID 13443700, compound

Product 1

HCID 10751406HCID 10751406, compound

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A solution of 5,8-dihydro-6,7-dimethyl-2-methoxynaphthalene-1,4-diol (2.00 g, 9.08 mmol) in MeOH (250 mL) was hydrogenated over Pd/C (200 mg, 10%, Aldrich) at 30-40 psi for 24 h at rt in a Parr hydrogenator. The catalyst was removed by filtration (Celite) and the solvent removed in vacuo to yield a brown tacky solid (~2.2 g, ~100%). Analysis (1H NMR) showed the solid to be a mixture of reduced diol (90%) and 2-methoxy-6,7-dimethylnaphthalene-1,4-dione. Without purification, the mixture was dissolved in CHCl3 (100 mL) and the resulting solution vigorously stirred with a solution of NaIO4 (3.89 g, 18.2 mmol, Baker) in H2O (200 mL) for 30 min at rt. The layers were separated and the aqueous portion extracted with CHCl3 (1×30 mL). The combined organic portion was washed with saturated brine (1×30 mL), filtered through a cotton plug and the solution concentrated in vacuo to yield a brown concentrate. The concentrate was passed through a silica gel column (2.5×17 cm) with CHCl3 elution to give an initial yellow band, which contained the desired product. Solvent removal in vacuo yield a brown oil (1.3 g). This material was further purified on a silica gel column (2.5×25 cm) to yield an orange viscous oil from the initial band (787 mg, 39%, pure by TLC and 1H NMR, as a probable mixture of cis- and trans-isomers (85 to 15)); 1H NMR (CDCl3) δ0.88 (d, J=6.6 Hz, 6H), 1.90 (m, 2H), 2.20 (m, 2H), 2.50 (m, 2H), 3.79 (s, 3H), 5.85 (s, 1H). The minor isomer shows a doublet at 1.03, J=6.0 Hz.

Workup

  1. customWithout purification
  2. dissolutionthe mixture was dissolved in CHCl3 (100 mL)
  3. customThe layers were separated
  4. extractionthe aqueous portion extracted with CHCl3 (1×30 mL)
  5. washThe combined organic portion was washed with saturated brine (1×30 mL)
  6. filtrationfiltered through a cotton plug
  7. concentrationthe solution concentrated in vacuo
  8. customto yield a brown concentrate
  9. washThe concentrate was passed through a silica gel column (2.5×17 cm) with CHCl3 elution
  10. customto give an initial yellow band, which

Sources & evidence

ORD record
ord-4dc08e8b104e4b538a46390ddbdc0c08
Source dataset
uspto-grants-1995_12
Patent number
US05476933

Reaction notes

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