Lawesson's reagent → (R)-6,6-difluoro-5-(2-fluoro-5-(pyrimidin-5-yl)phenyl)-5,7,7-trimethyl-1,4-oxazepane-3-thione

Participants

Reaction Conditions

Reaction Steps

A solution of (R)-6,6-difluoro-5-(2-fluoro-5-(pyrimidin-5-yl)phenyl)-5,7,7-trimethyl-1,4-oxazepan-3-one (263 mg, 720 μmol) in dioxane (24.0 ml) was treated at room temperature with Lawesson's reagent (233 mg, 576 μmol). The reaction mixture was stirred at 80° C. for 4 hours. For the workup, the reaction mixture was poured on a saturated solution of sodium hydrogencarbonate then extracted twice with ethyl acetate. The combined organic layers were washed with brine, dried over sodium sulphate, filtered and evaporated at reduced pressure to give brown oil. This residue was purified by chromatography on silica gel using a gradient of heptane/dichloromethane=100:0 to 20:80. The (R)-6,6-difluoro-5-(2-fluoro-5-(pyrimidin-5-yl)phenyl)-5,7,7-trimethyl-1,4-oxazepane-3-thione (244 mg, 89% yield) was obtained as a white foam. MS (ISP): m/z=382.1 [M+H]+.

Provenance & Evidence