GB839797A - Substituted thioureas and their use as pesticidal agents - Google Patents

Abstract

The invention comprises a process of preparing substituted thioureas of the general formula ArNHCSNRR1, wherein Ar represents an aryl radical, R represents an alkyl or cycloaliphatic radical and R1 represents hydrogen or an alkyl or cycloaliphatic radical, by reacting an alkyl, dialkyl or cycloaliphatic dithiocarbamic acid with a primary aryl amine. The substituted dithiocarbamic acid in the form of its sodium salt may be reacted with the sulphate of the aryl amine. A mixture of carbon disulphide and an alkyl, dialkyl or cycloaliphatic amine may be used in place of the substituted dithiocarbamic acid. In Example 3, a benzole forerunnings fraction containing CS2 is added to a mixture of dimethylamine, methanol and a coal-tar toluidine fraction of boiling-range 197-203 DEG C.; and the temperature is maintained at 75 DEG C. for 4 hours. The mixture is then cooled, and the solid product-N tolyl N1N1 dimethyl thiourea -is filtered off and washed with benzene. Example 4 relates to the preparation of N-phenyl N1N1 dimethyl thiourea. In Example 5, cyclohexylamine is reacted with CS2 in the presence of aqueous sodium hydroxide to form the sodium salt of cyclohexyl dithiocarbamic acid; and the latter is then reacted with toluidine sulphate to obtain N-tolyl N1 cyclohexyl thiourea. These substituted thioureas possess pesticidal properties (see Group VI).ALSO:Herbicidal and fungicidal compositions comprise as active ingredient one of the following substituted thioureas, viz. N-tolyl-N1,N1-dimethyl thiourea, N - phenyl - N1,N1 - dimethyl thiourea, and N-tolyl-N1-cyclohexyl thiourea. Details are given of phytotoxicity trials using each of the three compounds in the form of a 1% aqueous methanol suspension.