Reaktion #725733

Reaktionsgleichung

2-[3-(4-fluorobenzoyl)-isoxazol-5-yl]ethanol

H2SO4

→

powder

[3-(4-Fluorobenzoyl)isoxazol-5-yl]acetic acid

Lösungsmittel

CH2Cl2

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe organic phase was separated from the aqueous phase
2. 2
   Waschenwashed with water
3. 3
   ExtraktionThe acid product was extracted from the organic phase
4. 4
   WaschenThe alkaline solution was washed with CH2Cl2 several times
5. 5
   Sonstigeuntil all of the neutral impurities were removed
6. 6
   SonstigeThe precipitated solid was collected
7. 7
   Waschenwashed with water
8. 8
   Sonstigedried

Vorschrift

To a mixture of 13.5 g of 2-[3-(4-fluorobenzoyl)-isoxazol-5-yl]ethanol and a few crystals of tetrabutylammonium hydrogen sulfate in 1 liter of CH2Cl2 was added 150 ml of 9M H2SO4. To this was added 16.9 g of pulverized K2Cr2O7 and the mixture was stirred at room temperature for 1 hour. The organic phase was separated from the aqueous phase and washed with water. The acid product was extracted from the organic phase using 100 ml of 5% NaHCO3. The alkaline solution was washed with CH2Cl2 several times, until all of the neutral impurities were removed, and then acidified slowly with 5% HCl. The precipitated solid was collected, washed with water and dried to yield 6.7 g of a powder. Recrystallization from 180 ml of 50% toluene/hexane gave 5.9 g (41%) of crystals, m.p. 113°-115°.

Quelle