反应详情

The total crude material prepared in Example 80 was dissolved in acetic anhydride (25 mL) followed by slow addition of conc. H2SO4 (1 mL). The pot temperature reached 90° C. The reaction was then held at 90° C. for 1 h, cooled, and the acetic anhydride removed in vacuo. The residue was poured into ice water (250 mL) and extracted with EtOAc (300 mL total). The organic layer was then extracted with 1 N HCl (100 mL), saturated NaHCO3 (100 mL) and brine, separated, then dried with NaSO4 and concentrated to afford the title ester (4.6 g). The crude product used in the next step (Example 82).

1. customreached 90° C
2. temperaturecooled
3. customthe acetic anhydride removed in vacuo
4. additionThe residue was poured into ice water (250 mL)
5. extractionextracted with EtOAc (300 mL total)
6. extractionThe organic layer was then extracted with 1 N HCl (100 mL), saturated NaHCO3 (100 mL) and brine
7. customseparated
8. dry with materialdried with NaSO4
9. concentrationconcentrated