Lawesson's reagent → N-[4-(4-fluorophenyl)-2,2-dimethyl-3-thioxo-3,4-dihydro-2H-1,4-benzoxazin-7-yl]methanesulfonamide

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Reaction Steps

To a suspension of N-[4-(4-fluorophenyl)-2,2-dimethyl-3-oxo-3,4-dihydro-2H-1,4-benzoxazin-7-yl]methanesulfonamide (compound of Example 9, 182 mg) in dioxane (10 mL) was added Lawesson's reagent (202 mg), and the mixture was stirred at room temperature for 2 hours and then stirred at 40° C. for 24 hours. The reaction mixture was diluted with chloroform and the mixture was filtered through a NH-silica gel pad and washed with ethyl acetate. The filtrate and the washings were combined and concentrated in vacuo. The resultant residue was purified by column chromatography on silica gel (solvent; n-hexane/ethyl acetate=19/1→3/2) to give N-[4-(4-fluorophenyl)-2,2-dimethyl-3-thioxo-3,4-dihydro-2H-1,4-benzoxazin-7-yl]methanesulfonamide (25 mg) as a yellow powder.

Provenance & Evidence