反应详情

Stir a mixture of 136 mg. (0.5 mmole) of the ester of Example 7, 65.9 mg. (1 mmole) of 85% aqueous potassium hydroxide, 0.65 ml. of water, 3.25 ml. of ethanol, and 0.325 ml. of dioxane under argon at room temperature for 12 hours. Evaporate the mixture to dryness. Dissolve the residue in water and acidify with acetic acid. Recover the precipitate by filtration and wash with water. Dry in vacuo over calcium chloride and recrystallize from acetonitrile to obtain the title product (sinters and darkens at 237° C., m.p. 243° C. dec.).

1. additiona mixture of 136 mg
2. customEvaporate the mixture to dryness
3. dissolutionDissolve the residue in water
4. customRecover the precipitate
5. filtrationby filtration
6. washwash with water
7. dry with materialDry in vacuo over calcium chloride
8. customrecrystallize from acetonitrile