GB915907A - Herbicidal compositions containing substituted urea and thiourea herbicides - Google Patents

Abstract

Compounds of the general formula, <FORM:0915907/IV (b)/1> in which R1 represents a methyl or ethyl radical, X oxygen or sulphur, and R2 hydrogen or methyl are used with an inert carrier as herbicidal compositions, and are prepared by (1) reacting alkylcyclo-hexyl amine hydrohalides with phosgene to form corresponding isocyanates which are reacted with ammonia or an amine to form a substituted urea or (II) by reacting carbamic or thiocarbamic acid chloride with an alkyl cyclohexyl-amine in the presence of a tertiary amine as hydrogen chloride acceptor, at a temperature between 0 and 100 DEG C. The compounds may be used as compositions in an amount of 1 to 95% with liquid or solid fillers as preselective preemergence herbicides (Group VI).ALSO:Herbicidal compositions comprise as an active phytotoxic ingredient 1 to 95% by weight of a compound of general formula <FORM:0915907/VI/1> in which R1 represents methyl or ethyl radical, X represents oxygen or sulphur, and R2 represents hydrogen or methyl, together with an inert carrier. The compositions may be solutions in solvents such as cyclohexanol, isobutanol, ethanol or acetone, dispersions in a non-solvent such as water with surface-active agents of which a number are specified, or as a free flowing dust with finely divided solids such as talc pyrophyllite, walnut shell or soya bean flour, diatomaceous earth, bentonite, silica gel, calcium carbonate, or fertilizers such as calcium nitrate. The herbicides may be used as preemergence herbicides and are active against weeds such as Atriplex varieties, cruciferae, Stellaria media, Poa annua and Galinsoga varieties.