GB968666A - Herbicidal compositions containing 3-substituted uracils - Google Patents

Abstract

Compounds of the isomeric formulae: <FORM:0968666/C1/1> or <FORM:0968666/C1/2> where R1 is a covalent organic radical of molecular weight 15-250 which is C1-10 alkyl, substituted C1-3 alkyl, phenyl which may be substituted, C7-8 aralkyl, C7-12 substituted aralkyl, C3-6 alkenyl, propynyl, butynyl, C5-8 cycloalkyl or C5-8 cycloalkenyl; R2 is hydrogen, halogen, C1-4 alkyl, C1-3 alkoxy, NO2, C2-4 alkoxymethyl, hydroxymethyl, hydroxyethyl, allyl, thiocyanato, cyano, halogenomethyl or methylthiomethyl; R3 is hydrogen, C1-5 alkyl, methoxy or ethoxy; or R2 and R3 together make up (CH2)n, where n is 3, 4 or 5; and R4 is a covalent radical of molecular weight up to 250 which is C1-3 alkyl, hydroxymethyl, hydroxyethyl, carboxyethyl, substituted carbamyl, substituted thiocarbamyl, diethylphosphoryl, a chloromethylthio group, phenylthio, halogenophenylthio, nitrophenylthio, dinitrophenylthio, tolylthio or acyl; and X is oxygen or sulphur; with the proviso that if R2 is hydrogen and R4 is methyl, then R1 is C5-8 cycloalkyl or cycloalkenyl (such compounds bring herbicides (see Division A5) are prepared by methods involving introduction of the R4 group; methods used in examples are the use of ketone to give acetyl, dialkyl sulphates or sulphonates to give alkyl, acid chlorides to give acyl, diethylphosphorochloridate to give diethylphosphoro, propiolactone to give carboxyethyl, substituted carbamyl and thiocarbamyl chloride to give substituted carbamyl and thiocarbamyl, sulphenyl chlorides to give sulphenyl, formaldehyde to give hydroxymethyl, isocyanates and isothiocyanates to give substituted carbamyl and thiocarbamyl, and alkyl halides to give alkyl groups as R4. Novel compounds. 5-Chloro-3-cyclohexyl-1, 6-dimethyluracil is claimed as novel, as well as those compounds of the formula given in which (i) R1 is C5-8 cycloalkyl or cycloalkenyl, or a group -CR5R6R7 in which R5 is hydrogen or methyl, R6 is methyl or ethyl, and R7 is C1-5 alkyl; R2 is chlorine or bromine, X is oxygen or sulphur, R3 is methyl, and R4 is as defined above (but not methyl); and (ii) R1 is C1-10 alkyl, substituted C1-3 alkyl, phenyl which may be substituted, C7-8 aralkyl, C7-12 substituted aralkyl, C3-6 alkenyl, propynyl, butynyl, C5-8 cycloalkyl or cycloalkenyl, or cyano; R2 is halogen, R3 is methyl, and R4 is acyl. Specifications 492,742, 968,662, 968,663, 968,664 and 968,665 also are referred to.ALSO:The invention comprises herbicidal compositions comprising a compound of the isomeric formul <FORM:0968666/A5-A6/1> or <FORM:0968666/A5-A6/2> where R1 is a covalent organic radical of molecular weight 15-250 which is C1-10 alkyl, substituted C1-3 alkyl, phenyl which may be substituted, C7-8 aralkyl, C7-12 substituted aralkyl, C3-6 alkenyl, propynyl, butynyl, C5-8 cycloalkyl, C5-8 cycloalkenyl or cyano; R2 is hydrogen, halogen, C1-4 alkyl, C1-3 alkoxy, C2-4 alkoxymethyl, hydroxymethyl, hydroxyethyl, allyl, thiocyanato, cyano, halogenomethyl or methylthiomethyl; R3 is hydrogen, chlorine, C1-5 alkyl, methoxy or ethoxy, or R2 and R3 together make up (CH2)n where n is 3, 4 or 5; R4 is a covalent radical of molecular weight up to 250 which is C1-3 alkyl, hydroxymethyl, hydroxyethyl, carboxyethyl, substituted carbamyl, substituted thiocarbamyl, diethylphosphoryl, a chloromethylthio group, phenylthio, halogenophenylthio, nitrophenylthio, dinitrophenylthio, tolylthio or acyl; and X is oxygen or sulphur, with the proviso that if R2 is hydrogen and R4 is methyl, then R1 is C5-8 cycloalkyl or cycloalkenyl (see Division C2); associated with a compatible diluent which is (i) at least in part an oil (see below); (ii) at least in part a solid; (iii) at least in part a liquid other than an oil (e.g. water) and a surface-active agent; or (iv) a surface-active agent (which may also be present in (i) and (ii)). The invention also comprises a method of controlling the growth of weeds at a locus by applying to the locus a herbicidally effective quantity of at least one uracil as defined above, if desired in the form of a composition as defined. An oil is defined as a liquid immiscible with water and soluble in ether, and which boils at not below 125 DEG C. Specified diluents and additives are those referred to in the parent Specification. The compositions may also contain one of the 3-substituted uracils disclosed in Specifications 968,662, 968,663, 968,664 and 968,665. Specification 492,742 also is referred to.