GB826130A - Herbicidal compositions and substances for use therein - Google Patents

Abstract

Dithiocarbamic acid esters of the general formula <FORM:0826130/IV (b)/1> (wherein R1 and R2 each represent hydrogen or an alkyl, cycloalkyl, alkoxyalkyl, alkenyl, haloalkenyl, dihaloalkenyl, hydroxyalkyl or cyanoalkyl group of not more than 8 carbon atoms, and R3 represents an alkyl, alkenyl, alkynyl, haloalkenyl or dihaloalkenyl group, at least one of R1, R2 and R3 being a haloalkenyl or dihaloalkenyl group, and R2 being a haloalkenyl or dihaloalkenyl group when R3 is a haloalkenyl group) are prepared by condensing an alkali metal or ammonium salt of the appropriate dithiocarbamic acid with an alkyl or alkynyl halide or a mono-, di- or tri-haloalkene. The products are used in herbicidal compositions (see Group VI), and those in which at least one of R1 and R2 is a haloalkenyl or dihaloalkenyl group are claimed as new compounds. N - Haloalkenyldithiocarbamic acid salts are prepared by reacting carbon disulphide in the presence of aqueous caustic alkali with the corresponding haloalkenylamines, e.g. with 2-chloro-N - isopropylallylamine (from 2 : 3 - dichloro - 1-propene and isopropylamine), N-(3-chloro-2-butenyl) - cylohexylamine (from 1 : 3 - dichloro-2-butene and cyclohexylamine), 2-chloroallyl-31-methoxypropylamine (from 2 : 3-dichloro-1-propene and 3-methoxypropylamine) or bis-(2-chloroallyl)-amine (from sodium cyanamide and 2 : 3-dichloro-1-propene followed by hydrolysis of the resulting bis-(2-chloroallyl)-cyanamide by refluxing with dilute sulphuric acid).ALSO:Herbicidal compositions comprise a dithiocarbamic acid ester of the general formula <FORM:0826130/VI/1> (wherein R1 and R2 each represent hydrogen or an alkyl, cycloalkyl, alkoxyalkyl, alkenyl, haloalkenyl, dihaloalkenyl, hydroxyalkyl or cyanoalkyl group of not more than 8 carbon atoms, and R3 represents an alkyl, alkenyl, alkynyl, haloalkenyl or dihaloalkenyl group, at least one of R1, R2 and R3 being a haloalkenyl or dihaloalkenyl group, and R2 being a haloalkenyl or dihaloalkenyl group when R3 is a haloalkenyl group), dispersed in water or admixed with a finely divided solid carrier. The dispersions may be formed by directly dispersing the ester in water, or by dissolving the ester in an organic solvent and emulsifying the solution in water with the aid of a dispersing agent.