反应详情

The ester from Step 4 (3.0 g) in suspension in methanol (20 ml) and water (40 ml) at 0° was stirred vigorously during the portionwise addition of NaBH4 (1.8 g). The mixture was stirred for 2 hours at 5°. Acetone (1 ml) was added followed by acidification with 1N HCl and extraction with methanolchloroform (1:9, 3×50 ml). The combined extracts were dried (Na2SO4), reduced to dryness in vacuo and the residue was recrystallized from methanolethyl acetate to provide the title compound, m.p. 139°-140°.

1. extractionfollowed by acidification with 1N HCl and extraction with methanolchloroform (1:9, 3×50 ml)
2. dry with materialThe combined extracts were dried (Na2SO4)
3. customthe residue was recrystallized from methanolethyl acetate