反应详情

A mixture of 3-[(4-{[2-(2-furyl)-5-methyl-1,3-oxazol-4-yl]methoxy}benzyl)oxy]-1-phenyl-1H-pyrazole-4-carbaldehyde (0.60 g), hydroxylamine hydrochloride (0.14 g), pyridine (0.26 g) and ethanol (20 mL) was heated under reflux for 2 hrs. Water was poured into the reaction mixture, and the mixture was extracted with ethyl acetate. The ethyl acetate layer was washed with saturated brine, dried over anhydrous magnesium sulfate and concentrated. Acetic anhydride (20 mL) was added to residue, and the mixture was heated under reflux for 2 hrs. The reaction mixture was concentrated and ethyl acetate was added to the residue. The ethyl acetate layer was washed successively with water and saturated brine, dried over anhydrous magnesium sulfate and concentrated. The residue was subjected to silica gel column chromatography to give 3-[(4-{[2-(2-furyl)-5-methyl-1,3-oxazol-4-yl]methoxy}benzyl)oxy]-1-phenyl-1H-pyrazole-4-carbonitrile as colorless crystals (0.40 g, 68%) from a fraction eluted with ethyl acetate-hexane (1:1, v/v). Recrystallization from ethyl acetate-hexane gave colorless prism crystals. melting point: 158-159° C.

1. temperaturewas heated
2. temperatureunder reflux for 2 hrs
3. extractionthe mixture was extracted with ethyl acetate
4. washThe ethyl acetate layer was washed with saturated brine
5. dry with materialdried over anhydrous magnesium sulfate
6. concentrationconcentrated
7. additionAcetic anhydride (20 mL) was added to residue
8. temperaturethe mixture was heated
9. temperatureunder reflux for 2 hrs
10. concentrationThe reaction mixture was concentrated
11. additionethyl acetate was added to the residue
12. washThe ethyl acetate layer was washed successively with water and saturated brine
13. dry with materialdried over anhydrous magnesium sulfate
14. concentrationconcentrated