Reaktion #2380856

Reaktionsgleichung

4-hydroxycoumarin

1-(4-methylphenyl)-butan-1-ol

boron trifluoride etherate

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title product

Ausbeute 53.4%

4-Hydroxy-3-(1-(4-methylphenyl)-butyl)-coumarin

Ausbeute 53.4%

Lösungsmittel

dioxane

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONTo a flame-dried flask containing
2. 2
   workup.WAITThe resulting yellow solution is left
3. 3
   SonstigeThe volatiles are removed
4. 4
   WaschenThe basic aqueous phase is washed with diethyl ether
5. 5
   ExtraktionThe resulting precipitant is repeatedly extracted with dichloromethane (methanol-chloroform co-solvents)
6. 6
   WaschenThe combined dichloromethane extracts are washed once with dilute sodium bicarbonate
7. 7
   Sonstigeto remove most of the unreacted 4-hydroxycoumarin
8. 8
   Trocknenbrine, dried (magnesium sulfate)
9. 9
   Einengenfinally concentrated under reduced pressure
10. 10
    Sonstigechromatographed with 40% to 50% ethyl acetate in hexane

Vorschrift

To a flame-dried flask containing a mixture of 650 mg of 4-hydroxycoumarin and 980 mg of 1-(4-methylphenyl)-butan-1-ol of Preparation 20 in 20 mL of dioxane under an argon atmosphere is added 2.5 mL of boron trifluoride etherate. The resulting yellow solution is left to stir at room temperature overnight. The volatiles are removed and the residue is partioned between diethyl ether and 1N sodium hydroxide. The basic aqueous phase is washed with diethyl ether and acidified to pH=1 with 6N hydrochloric acid. The resulting precipitant is repeatedly extracted with dichloromethane (methanol-chloroform co-solvents). The combined dichloromethane extracts are washed once with dilute sodium bicarbonate to remove most of the unreacted 4-hydroxycoumarin, then brine, dried (magnesium sulfate), and finally concentrated under reduced pressure. The residue is adsorbed onto silica and flash column chromatographed with 40% to 50% ethyl acetate in hexane to yield 660 mg of the title product as a white solid.

Quelle