Reaction #49722

Reaction equation

Sodium acetate

hydroxylamine hydrochloride

3-cyclopropyl-2-ethoxymethylene-1-(2-fluoro-4-methylsulphonylphenyl)-propan-1,3-dione

→

4-cyclopropylcarbonyl-5-(2-fluoro-4-methylsulphonylphenyl)-isoxazole

Solvents

ethanol

Conditions

Workup

1. 1
   OtherThe solvent was evaporated
2. 2
   Otherthe residue was partitioned between ethyl acetate and water
3. 3
   WashThe organic phase was washed with water
4. 4
   Dryingdried (anhydrous magnesium sulphate)
5. 5
   Filtrationfiltered
6. 6
   Otherevaporated to dryness
7. 7
   OtherThe residue was triturated with ether
8. 8
   Filtrationfiltered
9. 9
   OtherThe resultant solid was recrystallized from methanol
10. 10
    OtherThe mother liquors from the recrystallization
11. 11
    Otherevaporated to dryness
12. 12
    OtherThe residue was purified by column chromatography on silica gel

Procedure

Sodium acetate (7.4 g) was added to a mixture of hydroxylamine hydrochloride (6.3g) and 3-cyclopropyl-2-ethoxymethylene-1-(2-fluoro-4-methylsulphonylphenyl)-propan-1,3-dione (29.0g) in ethanol. The mixture was stirred at room temperature overnight. The solvent was evaporated and the residue was partitioned between ethyl acetate and water. The organic phase was washed with water, dried (anhydrous magnesium sulphate) filtered and evaporated to dryness. The residue was triturated with ether and filtered. The resultant solid was recrystallized from methanol. The mother liquors from the recrystallization were combined and evaporated to dryness. The residue was purified by column chromatography on silica gel to give 4-cyclopropylcarbonyl-5-(2-fluoro-4-methylsulphonylphenyl)-isoxazole (compound 1) as a white solid, m.p. 129.5°-130.5° C.

Source