Method for producing alkylsulfinylbenzamides and 1,2-benzisothiazol-3-ones

A method for producing a 1,2-benzisothiazol-3-one represented by the general formula (VI), comprising carrying out a reaction of a 2-(alkylthio)benzamide represented by the following general formula (V):

• ##STR17## wherein R.sup.3 represents a hydrogen atom, or a linear or branched alkyl group having 1 to 12 carbon atoms, a cycloalkyl group, an aryl group, or an aralkyl group;
• R.sup.4 represents an alkyl group having 1 to 4 carbon atoms;
• R.sup.5 represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a nitro group, a carboxyl group or an ester thereof, or a halogen atom,
• with a halogenating agent selected from the group consisting of:
• a sulfuryl halide represented by the following general formula (VII):
• SO.sub.2 X.sub.2 (VII)
• wherein X represents Cl or Br,
• phosphorus pentachloride, phosphorus trichloride, and chlorine,
• to give a 1,2-benzisothizaol-3-one represented by the following general formula (VI):
• ##STR18## wherein R.sup.3 and R.sup.5 are defined as above.