Reaktion #50639

Reaktionsgleichung

6-hydroxy-7-phenylmethoxy-2H-1-benzopyran-2-one

cyclopentylbromide

potassium carbonate

potassium iodide

→

6-(cyclopentyloxy)-7-hydroxy-2H-1-benzopyran-2-one

Lösungsmittel

DMF

Reaktionsbedingungen

Aufarbeitung

1. 1
   FiltrationThis is followed by filtration, evaporation, dissolution in chloroform
2. 2
   Waschenwashing with water
3. 3
   Trocknendrying over sodium sulfate
4. 4
   Sonstigeevaporation
5. 5
   Sonstigeyield: 60.0 g (96%) of 6-(cyclopentyloxy)-7-(phenylmethoxy)-2H-1-benzopyran-2-one, fusion point 140°-141° C. (from isopropanol)
6. 6
   FiltrationAfter filtration the solvent
7. 7
   Sonstigeis removed
8. 8
   Sonstigeyield 9.0 g (82%), fusion point 154°-155° C. (from isopropanol and TBME)

Vorschrift

50.0 g (186 mmol) of 6-hydroxy-7-phenylmethoxy-2H-1-benzopyran-2-one, 41.7 g (280 mmol) of cyclopentylbromide, 51.4 g (372 mmol) of potassium carbonate and 5.0 g of potassium iodide are agitated in 500 ml DMF for 18 h at 80° C. This is followed by filtration, evaporation, dissolution in chloroform, washing with water, drying over sodium sulfate and renewed evaporation: yield: 60.0 g (96%) of 6-(cyclopentyloxy)-7-(phenylmethoxy)-2H-1-benzopyran-2-one, fusion point 140°-141° C. (from isopropanol). Of this 15.0 g (45 mmol) in 200 ml ethanol are hydrogenated in the presence of 2.0 g Pd on active carbon (5%) for 3 h at 25° C. and 7 bar hydrogen pressure. After filtration the solvent is removed: yield 9.0 g (82%), fusion point 154°-155° C. (from isopropanol and TBME).

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