GB973353A - New substituted ureas and herbicidal compositions containing them - Google Patents

Abstract

The invention comprises urea derivatives of the formula <FORM:0973353/C1/1> in which n is 1, 2 or 3 and at least one of R1 and R2 is a methoxy group, the other denoting a hydrogen atom or a methyl or a methoxy group. Compounds in which R1 is a methoxy group may be prepared by reacting an appropriate phenylhydroxylamine with an appropriate methyl-substituted carbamyl chloride or with methyl isocyanate to yield a 3-phenyl-3-hydroxyurea which is then methylated, e.g. with dimethyl sulphate. Compounds in which R2 is a methoxy group may be prepared by reacting an appropriate phenylisocyanate with N-methoxymethylamine. Examples are given in which (1) 3-(3, 4-dichlorophenyl)-3-hydroxy-1, 1-dimethylurea is methylated with dimethyl sulphate to yield the 3-methoxy compound, and (2) 3-(p-chlorophenyl)-3-hydroxy-1, 1-dimethyl urea is similarly methylated. Other specified products are 3-(p-chlorophenyl)-3-methoxy-1-methylurea, 3-(3,4-dichlorophenyl)-3-methoxy-1-methylurea, 3-(2, 4, 5-trichlorophenyl)-3-methoxy-1-methylurea and 3-(3, 4-dichlorophenyl)-1, 3-dimethoxy-1-methylurea. The products are useful as herbicides (see Division A5).ALSO:As components of herbicidal compositions, use is made of urea derivatives of the formula <FORM:0973353/A5-A6/1> in which n is 1, 2 or 3 and at least one of R1 and R2 is a methoxy group, the other denoting a hydrogen atom or a methyl or a methoxy group. Specified products include 3 - (3,4 - dichlorophenyl) - 3 - methoxy - 1,1 - dimethylurea, 3 - (p-chlorophenyl) - 3 - methoxy - 1,1 - dimethyl urea, 3 - (p - chlorophenyl) - 3 - methoxy - 1 - methylurea, 3 - (3,4 - dichlorophenyl) - 3 - methoxy - 1 - methylurea, 3 - (2,4,5 - trichlorophenyl) - 3 - methoxy - 1 - methylurea and 3 - (3,4 - dichlorophenyl) - 1,3 - dimethoxy - 1 - methylurea. The products may be formulated as solid or liquid compositions with the addition of solid or liquid diluents, a number of which are specified. The compositions may also contain other herbicides, the specified additional herbicides including, among others, 3-(3,4-dichlorophenyl) - 1,1 - dimethylurea, pentachlorophenol and salts thereof, 2-methoxy-3,5,6-trichlorobenzoic acid and salts thereof, 2,6 - dichlorobenzonitrile, 2 - (2,4,5 - trichlorophenoxy)propionic acid and salts and esters thereof, trichloroacetic acid and its salts, N-phenylcarbamic acid isopropyl ester, N,N-dipropylthiol carbamic acid ethyl ester, 2-chloro - N,N - diallylacetamide, maleic hydrazide, 2 - chloro - 4 - ethylamino - 6 - isopropylamino - 5 - triazine, disodium monomethyl arsonate, sodium arsenite, sodium metaborate, sodium chlorate, ammonium sulphamate and 6,7 - dihydrodipyrido - (1,2A,21,11C) - pyrazinium dibromide. The compositions may also contain surface-active agents, a number of which are specified. Fertilizers, insecticides and fungicides may also be included in the compositions. The compositions may be used for the treatment of growing weeds or they may be applied to the soil in areas where a growth of weeds might otherwise have been expected. Examples of herbicidal compositions are given.