Hydrogen Bromide → 2-bromomethyl-4-isopropyl-6-methoxy-1,2-benzisothiazol-3(2H)-one 1,1-dioxide

Participants

Reaction Steps

To a mixture of 4-isopropyl-6-methoxy-1,2-benzisothiazol-3(2H)-one 1,1-dioxide in acetic acid (20 ml) was added paraformaldehyde (0.7 g, 23.33 mmol), followed by 48% HBr in acetic acid (4.2 ml, 23.45 mmol). The mixture was heated at 50°-55° C. for 4 hours, cooled, poured over ice-water and filtered. The product was purified by column chromatography on silica gel eluting with 10-15% ethyl acetate/hexane to afford 1.88 g (66%) of 2-bromomethyl-4-isopropyl-6-methoxy-1,2-benzisothiazol-3(2H)-one 1,1-dioxide, m.p. 157°-159° C.

Provenance & Evidence