GB728969A - Manufacture of tribromo- and trichloro-methyl sulphone derivatives - Google Patents

Abstract

Tribromo- and trichloro-methyl sulphones are prepared by treating one molecular proportion of a thioglycollic acid, or a salt thereof, having the general formula R.S.CH2COOH in which R represents a -CH2COOH group or a hydrocarbon or heterocyclic radical which is attached through one of its carbon atoms to the sulphur atom of the above formula, and which may contain halogen, nitro, acylamino, alkoxy and sulpho substituents but no -CH2COOH groups, with, for each -CH2COOH grouping not less than 5, and preferably about 7 molecular proportions of a hypobromite or hypochlorite in the form of an aqueous solution containing hypobromite or hypochlorite ions. The products are mostly new and have pesticidal properties. In examples (1) an aqueous solution of phenyl thioglycollic acid and sodium hydroxide is added to aqueous sodium hypochlorite maintained at a temperature not exceeding 40 DEG C., the product being phenyl trichloro-methyl sulphone; phenyl tribromo-methyl sulphone is obtained using sodium hypobromite solution; (2) aqueous sodium hypo-bromite or -chlorite solution is rapidly added to cooled aqueous thiodiglycollic acid-yielding hexabromo (chloro) dimethyl sulphone. In like manner, ethyl-, 4-chlorophenyl-, 2 : 4 - and 2 : 5 - dichlorophenyl-, a 2 - methyl chloro phenyl -, 4 - chloro - 2-methyl phenyl-, b -phenyl ethyl-, 4-chloro-2-nitro phenyl-, 2-naphthyl-, 2-benzthiazyl- and 4-nitro phenyl-trichloromethyl sulphones and 2 : 4-dichlorophenyl tribromomethyl sulphone may be prepared.