Triethylamine → 3-Methyl-8-sulfamoyl-2,2-dioxo-1,2-benzoxathiine

Participants

Reaction Conditions

Reaction Steps

120 g of 6-bromo-2,2-dioxo-3-methyl-1,2-benzoxathiin-8-ylsulfonamide are dissolved in 2.4 liters of tetrahydrofuran and the solution is hydrogenated with hydrogen for 40 minutes, in the presence of 41.3 g of triethylamine and 12.0 g of 5% palladium on carbon catalyst, under normal pressure and in the temperature range from 20° to 25° C. The mixture is filtered, the filtrate is concentrated, and the residue is taken up in 1300 ml of hot 90% aqueous ethanol. The insoluble constituents are separated and the solution is cooled to 0° C. The precipitate is separated and dried, affording 70 g of 2,2-dioxo-3-methyl-1,2-benzoxathiin-8-ylsulfonamide of m.p. 204°-205° C.

Provenance & Evidence