反应详情

A solution of Intermediate 186a (1.0 g, 3.63 mmol) in EtOAc (20 mL) was treated with aqueous NaOH (1M, 6.53 mmol), followed by 2,2,2-trichloroethyl chloroformate (0.529 mL, 3.85 mmol) and the reaction mixture was stirred at RT for 1 h. The mixture was partitioned between EtOAc (20 mL) and water (20 mL). The layers were separated and the aqueous layer was extracted with a further 20 mL EtOAc. The combined organic layers were dried (Na2SO4), filtered and concentrated in vacuo. The residue was purified by FCC, using 0-40% EtOAc in DCM. The combined fractions were evaporated under reduced pressure and the product was triturated with DCM. The solid was filtered and washed with Diethyl ether to afford the title compound as a white solid (0.930 g, 58%). LCMS (Method 3): Rt 4.01 min, m/z 450 [M].

1. customThe mixture was partitioned between EtOAc (20 mL) and water (20 mL)
2. customThe layers were separated
3. extractionthe aqueous layer was extracted with a further 20 mL EtOAc
4. dry with materialThe combined organic layers were dried (Na2SO4)
5. filtrationfiltered
6. concentrationconcentrated in vacuo
7. customThe residue was purified by FCC
8. customThe combined fractions were evaporated under reduced pressure
9. customthe product was triturated with DCM
10. filtrationThe solid was filtered
11. washwashed with Diethyl ether