Reaktion #366660

Reaktionsgleichung

magnesium

bromoethane

N-methoxy-5, N-dimethyl-3-isoxazolcarboxamide

1-bromo-2-(1-ethoxyethyl)oxymethylbenzene

→

2-(1-ethoxyethyl)oxymethylphenyl 5-methylisoxazol-3-yl ketone

Ausbeute 90.2%

Lösungsmittel

THF

water

THF

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturcooled to −50° C
2. 2
   workup.STIRRINGThe mixture was stirred at −60° C. to room temperature for 1 hour
3. 3
   Extraktionthe mixture was extracted with ether (200 ml)
4. 4
   TrocknenThe extract was dried over anhydrous magnesium sulfate
5. 5
   Einengenconcentrated under reduced pressure
6. 6
   SonstigeThe residue was purified by silica gel chromatography (ethyl acetate/n-hexane)

Vorschrift

A mixture of 1-bromo-2-(1-ethoxyethyl)oxymethylbenzene (12.96 g, 0.05 mol) and THF (45 ml) was added to a mixture of magnesium (1.82 g, 0.075 mol) and bromoethane (0.2 ml) and THF (5 ml) at 45 to 55° C. under an atmosphere of nitrogen gas, and the resulting mixture was stirred at 50 to 55° C. for 1 hour to prepare a Grignard reagent. The Grignard reagent was added dropwise to a mixture of N-methoxy-5, N-dimethyl-3-isoxazolcarboxamide (5.62 g, 0.033 mol) and THF (40 ml) cooled to −50° C. The mixture was stirred at −60° C. to room temperature for 1 hour, water (200 ml) was added, and the mixture was extracted with ether (200 ml). The extract was dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was purified by silica gel chromatography (ethyl acetate/n-hexane) to give 2-(1-ethoxyethyl)oxymethylphenyl 5-methylisoxazol-3-yl ketone (8.61 g, yield: 90.2%) as a colorless oil.

Quelle