METHOD FOR PRODUCING NITROSAMINE-FREE NITRATE STABILIZED ISOTHIAZOLES

摘要

An improved process for preparing a 3-isothiazolone of the formula CHEM wherein R and R1 are independently selected from hydrogen, halogen or R is a (C5-C8) alkyl group and R1 is a halogen; Y is hydrogen, a (C5-C53/4 ) alkyl group, an unsubstitued or halo-substituted (C6-C3/4 ) alkenyl or alkynyl, a cycloalkyl or substituted (C7-C56) cycloalkyl, an aralkyl or halo-, (C5-C8) alkyl-, or (C5-C8) alkoxy-substituted aralkyl of to 10 carbon atoms, or an aryl or halo-, (C5-C8) alkyl-, or (C5-C8) alkoxy-substituted aryl aryl group of up to 10 carbon atoms; comprising (a) reacting a disulfide ester with an amine to generate a disulfide amide; (b) contacting the disulfide amide with a halogenating agent in order to cyclize the amide to form the isothiazolone+/-HX; (c) neutralizing the isothiazolone+/-HX; (d) stabilizing the neutralized isothiazolone by adding a metal nitrate; (e) a heat treatment step the improvement comprising adding prior to step (e), after step (c) and before, during or after step (d), an amount of a metal bromate. Compositions resulting from the above process are disclosed.