Lawesson's reagent → 3-(3,5-Dichloro-benzenesulfonylamino)-4-methoxy-N-phenyl-thiobenzamide

Participants

Reaction Conditions

Reaction Steps

A mixture of 3-(3,5-dichloro-benzenesulfonylamino)-4-methoxy-N-phenyl-benzamide from Example 118 (3.61 g, 8.0 mmol) and Lawesson's reagent (3.57 g, 8.8 mmol) was stirred at room temperature overnight in tetrahydro-furan (250 mL). The reaction mixture was warmed to 50° C. for about one hour, then to 65° C. for about 4 hours then stirred at room temperature overnight. The mixture was concentrated to dryness and the residue dissolved in ethyl acetate and filtered through silica gel. Concentration of the eluant followed by trituration in hexanes/ethyl acetate (1:1) afforded the crude product (3.06 g). A portion (0.8 g) of this was chromatographed on silica gel in hexanes/ethyl acetate (1:1) to afford a pure sample (0.324 g); m.p. 206-208° C.

Provenance & Evidence