反应详情

A solution of the mixed product from 18C (7.53 g, 26.5 mmol) in 120 mL of concentrated HCl/EtOH (1:1) was refluxed for 14 h. After cooling to rt, the solution was concentrated under reduced pressure. The resulting residue was dissolved in EtOAc, washed with saturated aqueous NaHCO3 (2×) and brine (1×), dried (MgSO4), filtered and concentrated. The residue was chromatographed (silica gel), eluting with chloroform/MeOH (98:2) to furnish the title compound (4.62 g, 87%). MS (ES) m/z 201 [M+1]+.

1. concentrationthe solution was concentrated under reduced pressure
2. dissolutionThe resulting residue was dissolved in EtOAc
3. washwashed with saturated aqueous NaHCO3 (2×) and brine (1×)
4. dry with materialdried (MgSO4)
5. filtrationfiltered
6. concentrationconcentrated
7. customThe residue was chromatographed (silica gel)
8. washeluting with chloroform/MeOH (98:2)