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

Participants

Reaction Steps

A mixture 4-isopropyl-6-methoxy-1,2-benzisothiazol-3(2H)-one 1,1-dioxide (0.51 g, 2 mmol), acetonitrile (5.0 ml), chloromethyl pivalate (0.32 ml, 2.2 mmol) and diisopropylethylamine (0.42 ml, 2.4 mmol) was heated to reflux until the starting material was consumed and then 33% HBr/acetic acid (2.4 g, 10 mmol) was added and the mixture was refluxed for 15 minutes. The reaction mixture was coooled, quenched with ice-water and filtered to afford 0.42 g (65%) of 2-bromomethyl-4-isopropyl-6-methoxy-1,2-benzisothiazol-3(2H)-one 1,1-dioxide, m.p. 158°-160.5° C., after recrystallization from ethyl acetate/hexane (3/2).

Provenance & Evidence