Isothiazoles II: 5‐chloro‐4‐isothiazolin‐3‐ones

Abstract

Abstract Quantitative gas chromatographic analysis of the 3‐hydroxyisothiazole product distributions formed in the chlorine induced cyclization of 3,3′ ‐dithiodipropionamide and 3‐mercaptopropion‐arnide has led to reaction conditions which yield respectively 3‐hydroxyisothiazole, 5‐chloro‐3‐hydroxyisothiazole, or 4,5‐dichloro‐3‐hydroxyisothiazole as the predominant product. The 4‐chloro analog was found in only small quantity. Similar glc analysis of the cyclization of N,N ′‐dimethyl‐3,3′‐dilhiodipropionamide showed 5‐ehloro‐2‐methyl‐4‐isothiazolin‐3‐one to he the major 4‐isothiazolin‐3‐one product under varied conditions. Also, a representative series of 5‐chloro‐2‐subtiuted‐4‐isohiazolin‐3‐oncs were prepared under extrapolated reaction conditions.