Ammonia → 6-Bromo-2,2-dioxo-3-methyl-1,2-benzoxathiin-8-ylsulfonamide

Participants

Reaction Conditions

Reaction Steps

A solution of 180 g of 6-bromo-2,2-dioxo-3-methyl-1,2-benzoxathiin-8-ylsulfonyl chloride in 500 ml of tetrahydrofuran is added dropwise over 30 minutes to 307 ml of a 30% aqueous solution of ammonia. The mixture is stirred for 30 minutes at 20° C. and concentrated under reduced pressure at 45° C. The residue is triturated with 200 ml of ether. The precipitate is isolated, washed with water and dried at 45° C., affording 63.2 g of 6-bromo-2,2-dioxo-3-methyl-1,2-benzoxathiin-8-ylsulfonamide of m.p. 243°-245° C. (crystallisation from ethanol).

Provenance & Evidence