Biologically active isothiazoles

The increasing understanding of the fundamental chemistry of the isothiazole system has enabled chemists to incorporate the ring into a wide variety of compounds with potential biological activity. 

Catteau, A. Lablanche-Combier, and A. Pollet, Chem. Commun. 1018 (1969). 

Examples of the four possible modes of fusion of isothiazole to pyrimidine have been described, namely, isothiazolo[3,4-d]-,53,54 -[4,3-d],112 -[4,5-d]-,112 and -[5,4-d]pyrimidine.8,10 A derivative of an isothiazolo[5,4-d]pyrimidine has been reported to possess antitumor activity,154 and others to have sedative properties.155 

Isothiazoles have also been incorporated into a wide range of established drugs including phenothiazines,123 sulfones,121 sulfonamides,3,66,156 thiosemicarbazones,140,157 amidines,158 nitrohetero-cycles,159 and benzimidazoles,160 but this approach does not appear to have resulted in any major improvements. However, many isothiazoles not directly related to known drugs have biological activity, and representatives are listed in Table I, No attempt has been made to include the numerous patents which mention isothiazole derivatives as part of a series, but for which no special claims are made. 

Freeman, A. Holland, D. Hossack, J. Inglis, J. Parkinson, 

---

Clerici F, Gelmi ML, Pellegrino S, Pocar D (2007) Recent developments in the chemistry of biologically active isothiazoles. 9 179-264... 

Within their contribution, Clerici et al. explain the chemistry of biologically active isothiazoles. They also present a range of different SAR studies, from well known to newly characterized compounds designed to improve their biological activities. In the same chapter, they also describe the agrochemical applications of the same pharmacophore. 

---