Acetic Anhydride → (5S,6S,9R)-6-(2,3-difluorophenyl)-9-(triisopropylsilyloxy)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-yl acetate

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Reaction Steps

In a 250 mL round-bottom flask was dissolved (5S,6S,9R)-6-(2,3-difluorophenyl)-9-(triisopropylsilyloxy)-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-5-ol (1.004 g, 2.243 mmol) in methylene chloride (20 mL) to give a colorless solution. Acetic anhydride (0.423 mL, 4.49 mmol) and triethylamine (0.938 mL, 6.73 mmol) were added, followed by DMAP (0.055 g, 0.449 mmol). The mixture was stirred at room temperature under nitrogen. 2 h: LCMS showed complete conversion. It was quenched with Sodium bicarbonate solution and diluted with ethyl acetate. The layers were separated. The organic layer was washed with brine, dried and concentrated to give a colorless oil (100%), which was directly carried onto next reaction without further purification and characterization. MS(ESI)[M+H+]=490.26.

Provenance & Evidence