7-Tert-butyl-chroman-4-ol → 7-(Tert-butyl)chroman-4-one

HRID 2092145

Reaction equation

HRID 2092145 reaction equation
[C:1]([C:5]1[CH:14]=[C:13]2[C:8]([CH:9]([OH:15])[CH2:10][CH2:11][O:12]2)=[CH:7][CH:6]=1)([CH3:4])([CH3:3])[CH3:2].[Cr](Cl)([O-])(=O)=O.[NH+]1C=CC=CC=1>ClCCl>[C:1]([C:5]1[CH:14]=[C:13]2[C:8]([C:9](=[O:15])[CH2:10][CH2:11][O:12]2)=[CH:7][CH:6]=1)([CH3:4])([CH3:2])[CH3:3]

Participants

4

Reactant 2

HCID 595485267-Tert-butyl-chroman-4-olHCID 178418287HCID 178418287, compound

Product 1

HCID 595485417-(Tert-butyl)chroman-4-oneYield 73%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

The crude 7-tert-butyl-chroman-4-ol from step B was dissolved in 50 ml dichloromethane. Pyridinium chlorochromate (4.31 g, 20 mmol) was added and the reaction mixture was stirred at ambient temperature for 3 hours, diluted with hexanes and filtered through a pad of celite. Solvent was removed from the filtrate under reduced pressure and the residue filtered through a pad of silica gel, eluting with 20% ethyl acetate:hexanes. Removal of solvent gave 2.37 g of crude product, which was chromatographed on silica gel with an eluent of 10% ethyl acetate:hexanes to give 1.50 g of the title compound (73% for 3 steps). 1H NMR (300 MHz, CDCl3) δ 7.83 (d, 1H, J=8.1 Hz), 7.07 (dd, 1H, J=8.3 and 1.9 Hz), 6.97 (d, 1H, J=1.7 Hz), 4.62 (m, 2H), 2.78 (m, 2H), 1.31 (s, 9H). MS (DCI) m/e 205 (M+H)+.

Workup

  1. filtrationfiltered through a pad of celite
  2. customSolvent was removed from the filtrate under reduced pressure
  3. filtrationthe residue filtered through a pad of silica gel
  4. washeluting with 20% ethyl acetate
  5. customRemoval of solvent
  6. customgave 2.37 g of crude product, which
  7. customwas chromatographed on silica gel with an eluent of 10% ethyl acetate

Sources & evidence

ORD record
ord-42bc413f09ed4c9a9e1f9dddbc569539
Source dataset
uspto-grants-2013_05
Patent number
US08440691B2

Linked notes

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