(Diethylamino)sulfur trifluoride → tert-Butyl (2-{7-[3-(4-cyanophenoxy)-2-fluoropropyl]-9-oxa-3,7-diazabicyclo[3.3.1]non-3-yl}ethyl)carbamate

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Reaction Steps

To a solution of DAST (0.73 g, 0.0043 mol) in dichloromethane (10 mL) was added tert-butyl (2-{7-[(2S)-3-(4-cyanophenoxy)-2-hydroxypropyl]-9-oxa-3,7-diazabicyclo[3.3.1]non-3-yl}ethyl)carbamate (1.50 g, 0.0033 mol; see Preparation R above), in (10 mL) of dichloromethane, dropwise under a nitrogen atmosphere at −65° C. The reaction mixture was slowly brought to RT and stirred at this temperature for 2 h (monitored by HPLC). The reaction mixture was quenched with NaHCO3 (aq.) and extracted with dichloromethane. The organic layer was washed with water and brine and then dried over sodium sulfate. Solvent was evaporated under reduced pressure and the residue was purified by column chromatography over silica gel, using methanol-dichloromethane as the eluent, to yield 0.40 g of the title compound as a brownish, gummy solid.

Provenance & Evidence