反应详情

A solution of DDQ (3.06-4.09 g) in dioxane (40 mL) was added dropwise over a period of 10 min to a ice cold and well stirred solution of 2,4,5-trimethoxyphenylpropane (1.89 g, 0.009 mol) in wet dioxane or ethanol (55 mL) and the resulting mixture was stirred at room temperature for over night. The precipitate was filtered and further washed twice with dioxane. The combined dioxane layer was evaporated and mixture was poured into water and extracted with dichloromethane (3×70 mL). The combined organic layer were washed with brine (3×15 mL) and dried over sodium sulphate. The residue obtained on evaporation of the solvents was chromatographed on silica gel column using hexane-ethyl acetate mixture with increasing proportion of ethyl acetate upto 40% to afford viscous liquid which was crystallized from ethylacetate/hexane to afford 1.19 g (59%) of white crystals of isoacoramone. The spectral data was found similar as mentioned above in Example III.

1. filtrationThe precipitate was filtered
2. washfurther washed twice with dioxane
3. customThe combined dioxane layer was evaporated
4. additionmixture was poured into water
5. extractionextracted with dichloromethane (3×70 mL)
6. washThe combined organic layer were washed with brine (3×15 mL)
7. dry with materialdried over sodium sulphate
8. customThe residue obtained on evaporation of the solvents
9. customwas chromatographed on silica gel column
10. temperaturewith increasing proportion of ethyl acetate upto 40%
11. customto afford viscous liquid which
12. customwas crystallized from ethylacetate/hexane