Method for producing 2-alkyl-4-isothiazoline-3-one

Abstract

Chlorinating agent is reacted with a compound represented by formula (I) (wherein R represents C1 to C8 alkyl groups or aralkyl groups) or a compound represented by formula (II) in a solvent in which hydrogen chloride is insoluble or has low solubility.

What is claimed is:  
     
         1 . An industrial disinfectant composition comprising, as an effective component, a 2-alkyl-4-isothazoline-3-one represented by the formula (III),  
       
         
           
           
               
               
           
         
       
       which is obtained by reacting the compound represented by formula (II),  
       
         
           
           
               
               
           
         
       
       with chlorine as a chlorinating agent in dichloromethane as a solvent, in which hydrogen chloride is insoluble or exhibits low solubility, at a temperature of 39-41° C., according the reaction formula represented by:  
       
         
           
           
               
               
           
         
         wherein R in the compounds of formulae (II) and (III) represents an alkyl group or aralkyl group of C1 to C8, and  
         wherein the amount of a 5-chloro-2-alkyl-4-isothiazoline-3-one contained in the 2-alkyl-4-isothiazoline-3-one produced is less than 0.1%.  
       
     
     
         2 . The method producing a 2-alkyl-4-isothazoline-3-one as defined in  claim 1 , wherein the R represents a methyl group.  
     
     
         3 . The method producing a 2-alkyl-4-isothazoline-3-one as defined in  claim 1 , wherein the R represents a normal octyl group.  
     
     
         4 . An industrial disinfectant composition comprising, as an effective component, a 2-alkyl-4-isothazoline-3-one represented by the formula (III),  
       
         
           
           
               
               
           
         
       
       which is obtained by reacting the compound represented by formula (II),  
       
         
           
           
               
               
           
         
       
       with chlorine as a chlorinating agent in dichloromethane as a solvent, in which hydrogen chloride is insoluble or exhibits low solubility, at a temperature of 39-41° C., according the reaction formula represented by:  
       
         
           
           
               
               
           
         
         filtrating a hydrochloride salt of the compound of formula (III) obtained from the reaction of the compound of formula II with chlorine, and  
         washing the hydrochloride salt with a solvent which is inert to the hydrochloride salt and in which the hydrochloride salt exhibits low solubility,  
         wherein R in the compounds of formulae (II) and (III) represents an alkyl group or aralkyl group of C1 to C8, and  
         wherein the amount of a 5-chloro-2-alkyl-4-isothiazoline-3-one contained in the 2-alkyl-4-isothiazoline-3-one produced is less than 0.1%.  
       
     
     
         5 . The method producing a 2-alkyl-4-isothazoline-3-one as defined in  claim 4 , wherein the R represents a methyl group.  
     
     
         6 . The method producing a 2-alkyl-4-isothazoline-3-one as defined in  claim 4 , wherein the R represents a normal octyl group.