反应详情

To a cooled solution (0° C.) of #203 (7.0 g, 10.77 mmol, 1 eq.) in dichloromethane (15 mL) was added dropwise pyridine (3.41 g 43.08 mmol, 4 eq.) followed by a solution of pentafluorophenyl trifluoroacetate (6.03 g, 21.54 mmol, 2 eq.) in dichloromethane (7 mL). The mixture was stirred at room temperature for one hour, and the solvent was concentrated in vacuo. The residue was purified by silica gel chromatography (Gradient: 1 to 10% methanol in dichloromethane) to afford compound #204 (8 g, 82% over two steps) as yellow solid.

1. concentrationthe solvent was concentrated in vacuo
2. customThe residue was purified by silica gel chromatography (Gradient: 1 to 10% methanol in dichloromethane)