Patent ID: 6376680
Filing Date: 2002-04-23
Classification: A01N,A23L,A61K,A61Q,C07D

Abstract:
A process for preparing a mixture of 2-methyl-4-isothiazolin-3-one of formula (I) and 5-chloro-2-methyl-4-isothiazolin-3-one of formula (II) which comprises: reacting N-methyl-3-mercaptopropionamide of formula (A-1) or N,Nâ€²-dimethyl-3,3â€²-dithiodipropionamide of formula (A-2) or a mixture thereof dissolved in a first organic solvent with sulfuryl chloride dissolved in a second organic solvent which is different from the first organic solvent, while maintaining the reaction temperature in the range of 5 to 20Â° C. to obtain said mixture containing 4,5-dichloro-2-methyl-4-isothiazolin-3-one in an amount of less than 100 ppm: