Lawesson's reagent → (R)-5-(5-bromo-2-fluoro-phenyl)-5-methyl-1,1-dioxo-1lambda6-thio morpholin-3-thione

Participants

Reaction Conditions

Reaction Steps

To a solution of (R)-5-(5-bromo-2-fluoro-phenyl)-5-methyl-1,1-dioxo-1λ6-thio morpholin-3-one (3.11 g, 9.25 mmol, Eq: 1.00) in dioxane (72.3 ml) was added Lawesson's reagent (2.99 g, 7.4 mmol, Eq: 0.8) at 23° C. The mixture was stirred for 2 hours at 80° C. Diluted with sat. NaHCO3-sol., extracted with ethyl acetate, washed with brine, dried over Na2SO4 and filtered off. Removal of solvent in vacuum left a yellow oil (5.8 g), which was purified by flash chromatography on 50 g silica gel with 0-50% ethyl acetate in heptane to give the (R)-5-(5-bromo-2-fluoro-phenyl)-5-methyl-1,1-dioxo-1λ6-thio morpholin-3-thione (2.7 g, 7.67 mmol, 82.9% yield) as a light yellow foam. MS (ISN): m/z=350.1 [M−H]− and 352.2 [M+2−H]−.

Provenance & Evidence