反应详情

A suspension of 7.0 g 5-[5-(2,6-dimethyl-4-cyanophenoxy)pentyl]-3-methylisoxazole, 1.8 g hydroxylamine hydrochloride and 3.5 g sodium acetate trihydrate in 40 ml 95% ethanol was heated at reflux under nitrogen for two days. The reaction mixture was filtered, concentrated in vacuo, and the residue in 50 ml acetic anhydride was heated at reflux for 3 hrs. The reaction mixture was poured over ice/10% sodium hydroxide and extracted with ether. The ether extracts were washed with water and saturated sodium bicarbonate, dried (K2CO3), concentrated and subjected to flash filtration (silica gel 60, 3:1 hexane/ethyl acetate) followed by chromatography (MPLC, silica gel 60, 3:1 hexane/ethyl acetate). The resulting product was crystallized from isopropyl acetate/hexane to give 2.7 g 5-{5-[2,6-dimethyl-4-(5-methyl-1,2,4-oxadiazol-3-yl)phenoxy]pentyl}-3-methylisoxazole, m.p. 45°-46° C.

1. temperaturewas heated
2. temperatureat reflux under nitrogen for two days
3. filtrationThe reaction mixture was filtered
4. concentrationconcentrated in vacuo
5. temperaturethe residue in 50 ml acetic anhydride was heated
6. temperatureat reflux for 3 hrs
7. additionThe reaction mixture was poured over ice/10% sodium hydroxide
8. extractionextracted with ether
9. washThe ether extracts were washed with water and saturated sodium bicarbonate
10. dry with materialdried (K2CO3)
11. concentrationconcentrated
12. filtrationsubjected to flash filtration (silica gel 60, 3:1 hexane/ethyl acetate)
13. customThe resulting product was crystallized from isopropyl acetate/hexane