The chemistry and fungicidal and phytotoxic properties of heterocyclic sulfonyl‐, sulfinyl‐, and thio‐methyl thiocyanates

Abstract

The synthesis of 38 compounds with structure R-SOn-CHe-SCN, in which R is a heterocyclic radical and n = 0, 1 , or 2 , is described and their fungicidal and phytotoxic activities are discussed. IntroductionAs described and discussed in a previous paper from these Laboratories, arylsulfonyl-and arylsulfinyl-methyl thiocyanates showed high fungicidal activity, combined with low phytotoxicity. Those properties make these compounds very useful for phytopharmaceutical application. In continuation of this investigations a number of compounds of this type with an aromatic heterocyclic radical was synthesized and screened for fungicidal activity.

Polychloroheteroaromatic Compounds

“…Polychloro-2-mercaptobenzothiazoles may be prepared from a polychloroaniline through reaction of the amine with sulphur monochloride, followed by alkali (the Herz reaction), and cyclization of the resulting o-aminothiophenol with carbon disulphide [679,680]; for example, 2,3-dichloroaniline gives a poor yield of 4,5,6-trichloro-2-mercaptobenzothiazole (316; R = SH) (Herz reactions are accompanied by ring chlorination para to the aminogroup) [680].…”

“…It is noteworthy that 4,6,7 -trichloro-2-mercaptobenzothiazolylmethylchloroarsine and bis(tetrachloro-2-mercaptobenzothiazolyl)methylarsine are claimed [681] to possess useful insecticidal properties and that compound (316; R = SCH2 SCN), which may be prepared from 4,5,6-trichloro-2-mercaptobenzothiazole by condensation with chloromethyl thiocyanate, exhibits fungicidal activity, as do its sidechain sulphone and sulphoxide [680].…”