反应详情

To a solution of EXAMPLE 92A (2.65 g, 8.2 mmol) in tetrahydrofuran (20 mL) was added lithium hydroxide monohydrate (688 mg, 16.4 mmol) in 20 mL of water and methanol added until a transparent solution formed. This mixture was stirred at ambient temperature for 2 hours and acidified with 2N hydrochloric acid to pH 2. The mixture was concentrated to about 10 mL, diluted with water and let stand at ambient temperature overnight. The white solid was collected by filtration, washed with water and dried to give the title compound (2.21 g). Recrystallization from methanol and water gave 1.61 g of title compound.

1. additionadded until a transparent solution
2. customformed
3. concentrationThe mixture was concentrated to about 10 mL
4. additiondiluted with water
5. waitlet stand at ambient temperature overnight
6. filtrationThe white solid was collected by filtration
7. washwashed with water
8. customdried