反应详情

A mixture of tetrahydro-3,5-bis-(phenylmethylene)-4H-pyran-4-one (3.6 g, 13 mmole) and propylhydrazine (1.1 g, 14 mmole) in methanol (250 ml) is heated at reflux temperature for 3-4 hours. MeOH is then removed in vacuo. The residue is dissolved in CHCl3 and washed with dilute HCl and water, then dried (anhydrous MgSO4) and concentrated in vacuo to give a yellow oil. When this crude oil is triturated with a small amount of acetonitrile the major product of this reaction precipitates out. The filtrate is concentrated and the residue is applied to a dry-packed Al2O3 (Activity I, neutral) column. The fractions eluted with ether are combined and recrystallized first from ether/hexane, then from cyclohexane until a constant m.p. (126.5°-128.5° C.) is reached, giving the product in crystalline form (99% pure).

1. temperatureis heated
2. temperatureat reflux temperature for 3-4 hours
3. customMeOH is then removed in vacuo
4. dissolutionThe residue is dissolved in CHCl3
5. washwashed with dilute HCl and water
6. dry with materialdried (anhydrous MgSO4)
7. concentrationconcentrated in vacuo
8. customto give a yellow oil
9. customWhen this crude oil is triturated with a small amount of acetonitrile the major product of this reaction
10. customprecipitates out
11. concentrationThe filtrate is concentrated
12. washThe fractions eluted with ether
13. customrecrystallized first from ether/hexane
14. customuntil a constant m.p. (126.5°-128.5° C.)
15. customgiving the product in crystalline form (99% pure)