Trioxogrisan derivatives

The invention comprises compounds of formula where R is an alkyl radical, a benzyl radical or a phenyl radical which may be substituted by methyl, methoxy or nitro radicals or by halogen atoms. The compounds may be substituted at positions 4, 5, 6, 7, 31, 51 and/or 61 by halogen, methyl or methoxy radicals e.g. at positions 4 and/or 6 by methoxy radicals, at positions 5 and/or 7 by chlorine or bromine atoms, and at positions 31, 51 and/or 61 by methyl radicals. The compounds may be prepared by reacting a compound of formula which may be substituted as above, with a sulphenyl halide or thiocyanate of formula RSX where X is chlorine, bromine, iodine or the thiocyanate radical. Examples are given. Benzylsulphenyl bromide is prepared by reacting benzyl mercaptan with N-bromosuccinimide; t-butylsulphenyl chloride is prepared by reacting sulphenyl chloride with bis-t-butyl disulphide; o-methoxphenylsulphenyl chloride is prepared by reacting o-methoxythiophenol with N-chlorosuccinimide; and isopropylsulphenyl chloride is prepared by reacting propane-2-thiol with N-chlorosuccinimide.