2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → Exemestane

Beteiligte Stoffe

Reaktionsschritte

0.50 g of 6-methylenandrost-4-ene-3,17-dione and 0.57 g of dichlorodicyanobenzoquinone were refluxed in 20 ml of anhydrous dioxane for about 15 hours. To remove the DDQ the suspension was filtered through alumina. After evaporation of the solvent the residue was dissolved in ethyl acetate, the organic layer washed with water, dried over sodium sulfate and the solent removed under vacuum. The crude product was chromatographed on silica gel using hexane/ethyl acetate 40% to yield 0.25 g of pure 6-methylenandrosta-1,4-diene-3,17-dione, m.p. 188°-191° C., λmax 247 mμ (ε13.750). Found: C 81.01, H 8.05. C20H24O2 requires: C 81.04, H 8.16.

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