1-oxothian-4-one

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a stirred solution of 3-amino-5-(pyridin-4-yl)thiophene-2-carboxamide (0.050 g, 0.23 mmol) in acetic acid (3 mL) were added tetrahydro-4H-thiopyran-4-one 1-oxide (0.061 g, 0.46 mmol) and p-toluenesulfonic acid (0.0040 g, 0.023 mmol). The mixture was heated at 80° C. overnight. Then, the solvent was removed and the obtained residue was taken up in methanol (20 mL). Solid NaHCO3 (1.5 g) was added, and the mixture was stirred for 10 min. The mixture was filtered, and the filtrate was chromatographed (Combiflash, silica gel, dichloromethane to 80:20 dichloromethane/methanol) to give the title compound (0.0127 g, 16%) as a yellow solid: Then, the solvent was removed Solid NaHCO3 (1.5 g) was added The mixture was filtered the filtrate was chromatographed (Combiflash, silica gel, dichloromethane to 80:20 dichloromethane/methanol)

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a stirred solution of 3-amino-5-(pyridin-4-yl)thiophene-2-carboxamide (0.050 g, 0.23 mmol) in acetic acid (3 mL) were added tetrahydro-4H-thiopyran-4-one 1-oxide (0.061 g, 0.46 mmol) and p-toluenesulfonic acid (0.0040 g, 0.023 mmol). The mixture was heated at 80° C. overnight. Then, the solvent was removed and the obtained residue was taken up in methanol (20 mL). Solid NaHCO3 (1.5 g) was added, and the mixture was stirred for 10 min. The mixture was filtered, and the filtrate was chromatographed (Combiflash, silica gel, dichloromethane to 80:20 dichloromethane/methanol) to give the title compound (0.0127 g, 16%) as a yellow solid: Then, the solvent was removed Solid NaHCO3 (1.5 g) was added The mixture was filtered the filtrate was chromatographed (Combiflash, silica gel, dichloromethane to 80:20 dichloromethane/methanol)