Reaktion #416707

Reaktionsgleichung

1-bromo-3-(2-tetrahydropyranyl)oxypropane

butyllithium

diisopropylamine

3-hydroxy-5-methylisoxazole

→

title compound

Ausbeute 71.3%

3-Hydroxy-5-[4-(2-tetrahydropyranyl)oxybutyl]isoxazole

Ausbeute 71.3%

Lösungsmittel

hexane

tetrahydrofuran

water

acetic acid

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGThe mixture was then stirred at -10° C. for 30 minutes
2. 2
   Temperaturafter which it was cooled to -50° C.
3. 3
   workup.STIRRINGThe mixture was then stirred at 15°-20° C. for 2 hours
4. 4
   SonstigeThe organic layer was separated
5. 5
   workup.ADDITIONby adding 10%
6. 6
   Extraktionfollowed by extraction twice with diethyl ether
7. 7
   WaschenThe combined organic layer and extracts were washed with water
8. 8
   Trocknendried over anhydrous magnesium sulfate
9. 9
   Einengenconcentrated by evaporation under reduced pressure
10. 10
    Sonstigeto give a residue, which

Vorschrift

13.95 ml of a 15% by weight solution of butyllithium in hexane were added dropwise, at -25° to -15° C., to a solution of 3.08 ml of diisopropylamine in 100 ml of tetrahydrofuran. The mixture was stirred at -20° C. for 15 minutes, after which a solution of 0.990 g of 3-hydroxy-5-methylisoxazole in 10 ml of tetrahydrofuran was added to the mixture at -20° to -10° C. over a period of 10 minutes. The mixture was then stirred at -10° C. for 30 minutes, after which it was cooled to -50° C., and then 3.35 g of 1-bromo-3-(2-tetrahydropyranyl)oxypropane were added to it all at once. The mixture was then stirred at 15°-20° C. for 2 hours, after which it was mixed with 1.20 ml of acetic acid. It was then poured into water. The organic layer was separated and the aqueous layer was adjusted to a pH value of 3 by adding 10% w/v aqueous hydrochloric acid followed by extraction twice with diethyl ether. The combined organic layer and extracts were washed with water, dried over anhydrous magnesium sulfate and concentrated by evaporation under reduced pressure, to give a residue, which was subjected to column chromatography through 60 g of silica gel. 1.720 g of the title compound was obtained, as a colorless oil, from the fractions eluted with mixtures of ethyl acetate and hexane ranging from 1:2 to 1:1 by volume.

Quelle