Cornforth reagent → Methyl 2-methoxy-1-(3-methylbutyl)-4-oxo-1,4-dihydronaphthalene-1-carboxylate

HRID 2110564Notes

Reaction equation

HRID 2110564 reaction equation
[CH3:1][O:2][C:3]1[C:4]([CH2:17][CH2:18][CH:19]([CH3:21])[CH3:20])([C:13]([O:15][CH3:16])=[O:14])[C:5]2[C:10]([CH2:11][CH:12]=1)=[CH:9][CH:8]=[CH:7][CH:6]=2.[Cr](O[Cr]([O-])(=O)=O)([O-])(=O)=[O:23].[NH+]1C=CC=CC=1.[NH+]1C=CC=CC=1>C(Cl)(Cl)Cl>[CH3:1][O:2][C:3]1[C:4]([CH2:17][CH2:18][CH:19]([CH3:21])[CH3:20])([C:13]([O:15][CH3:16])=[O:14])[C:5]2[C:10]([C:11](=[O:23])[CH:12]=1)=[CH:9][CH:8]=[CH:7][CH:6]=2

Participants

4

Reactant 2

HCID 2724130Cornforth reagentHCID 68838307Methyl 2-methoxy-1-(3-methylbutyl)-1,4-dihydronaphthalene-1-carboxylate

Product 1

HCID 68842102Methyl 2-methoxy-1-(3-methylbutyl)-4-oxo-1,4-dihydronaphthalene-1-carboxylateYield 59.5%

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent

Procedure

A mixture of Example 2A (0.3g, 1.0 mmol) and pyridinium dichromate (0.98 g, 2.6 mmol) in chloroform (20 mL) was heated at reflux with a Dean-Stark trap for 18 h. The reaction mixture was cooled to room temperature and filtered through celite. The filtrate was concentrated in vacuo. Column chromatography on silica (5% →15% ethyl acetate/hexane) afforded the title compound as a white solid (0.18 g, 58%). 1H NMR (300 MHz, CDCl3) δ ppm 0.40(m, 1H), 0.72 (m, 7H), 1.37(m, 1H), 2.36(m, 2H), 3.61 (s, 3H), 3.83(s, 3H), 5.96 (s, 1H), 7.42 (m, 2H), 7.56 (m, 1H), 8.19 (d, J=7.72 Hz, 1H); MS m/z 303.1 (M+H)+.

Workup

  1. temperatureat reflux with a Dean-Stark trap for 18 h
  2. filtrationfiltered through celite
  3. concentrationThe filtrate was concentrated in vacuo

Sources & evidence

ORD record
ord-3a0617a2e5eb49a297471c03bfc0dbdd
Source dataset
uspto-grants-2009_04
Patent number
US07517876B2

Reaction notes

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