反应详情

To a solution of the ester (Step III) in 20 mL of THF/MeOH (1:1) was added NaOH (6 mL, 1M). After 1 h at RT, the reaction was acidified with aqueous citric acid and the organic phase was partially evaporated. The solid was filtered off, washed with water and recrystallized from ethyl acetate/hexane to afford the title compound. m.p. 141°-143°.

1. customthe organic phase was partially evaporated
2. filtrationThe solid was filtered off
3. washwashed with water
4. customrecrystallized from ethyl acetate/hexane