反应详情

3.2 g (9.25 mmol) of the compound of Example 51A were dissolved in 28 ml of methanol. 2.82 ml of a 20% strength aqueous potassium hydroxide solution were then added. The mixture was stirred at RT for 2 h. On a rotary evaporator, the proportion of methanol was reduced by half. The mixture was then diluted with water and extracted once with 15 ml of ethyl acetate. The aqueous phase was acidified with 920 μl of concentrated hydrochloric acid and extracted twice with in each case 15 ml of ethyl acetate. The combined organic phases were dried over sodium sulphate, filtered and freed from the solvent on a rotary evaporator. Drying the residue under high vacuum gave 2.34 g (80% of theory) of the title compound.

1. customOn a rotary evaporator
2. additionThe mixture was then diluted with water
3. extractionextracted once with 15 ml of ethyl acetate
4. extractionextracted twice with in each case 15 ml of ethyl acetate
5. dry with materialThe combined organic phases were dried over sodium sulphate
6. filtrationfiltered
7. customfreed from the solvent on a rotary evaporator
8. customDrying the residue under high vacuum