GB692589A - Improvements in herbicidal compositions - Google Patents

Abstract

Aryl ureas and thioureas of general formula <FORM:0692589/IV (b)/1> where Ar is an aromatic radical; X is oxygen or sulphur; and one or all three of the nitrogen valence bonds are singly attached to monovalent aliphatic hydrocarbon radicals having from 1 to 3 carbon atoms, any remaining nitrogen valence bonds being attached to hydrogen; are prepared by reacting an aliphatic or aromatic primary or secondary amine with an isocyanate, isothiocyanate, carbamyl chloride or thiocarbamyl chloride. It is preferred to use an excess of the amine, to carry out the reaction in the presence of an inert liquid diluent, e.g. benzene, dioxane or water (where reactants are soluble therein), at a temperature of 0-100 DEG C., especially 15-75 DEG C. For reactions with carbamyl chloride or thiocarbamyl chloride, acid acceptors such as tertiary amines, especially triethylamine, dimethylaniline and pyridine, may be present. The preparation of the following is described: 1-phenyl-3-methylurea; 1 - (p - chlorophenyl) - 3,3 - dimethylurea; 1 - phenyl - 1,3 - dimethylurea; 1 - phenyl - 1 - methylurea; 1 - (p - tolyl) - 2 - thio - 3 - allylurea; 1 - phenyl - 2 - thio - 3,3 - dimethylurea; 1 - phenyl - 1 - methyl - 2 - thio - 3 - allylurea; 1 - phenyl - 1 - methyl - 2 - thiourea; 1 - phenyl-1,3,3 - trimethylurea; 1 - (m - tolyl) - 3,3 - dimethylurea; and 1 - phenyl - 2 - thio - 1,3,3 - trimethylurea. Among other specified compounds are: 1-(2-naphthyl)-3,3-dimethylurea; 1 - (p - nitrophenyl) - 3,3 - diethylurea; 1 - (m - fluorophenyl) - 3,3 - diethylurea; 1 - (p - iodophenyl) - 3,3 - diethylurea; 1 - (p - carbomethoxyphenyl) - 3,3 - diethylurea; 1 - (2 - phenylmercapto - 5 - carbomethoxyphenyl) - 3,3 - diethylurea; 1-(2,4-dichlorophenyl)-3,3-dimethyl urea; and the dimethylamine salt of 1-(p-sulphophenyl) - 3,3 - dimethylurea. In general, the Ar of the general formula above may be phenyl, alkyl phenyl, nitrophenyl, aminophenyl and halogenophenyl, the halogens being fluorine, chlorine, bromine or iodine.ALSO:A herbicidal composition comprises one or more polysubstituted ureas of general formula:- <FORM:0692589/VI/1> where Ar is an aromatic radical, X is oxygen or sulphur, and one, two or all three of the nitrogen valence bonds are singly attached to monovalent aliphatic hydrocarbon radicals having one to three carbon atoms, any remaining nitrogen valence bonds being directly attached to hydrogen, homogeneously dispersed in a non-solvent fluent carrier and/or associated with a surface active agent, the carrier and/or agent being chemically inert to the substituted urea or ureas. Specified solid carriers are talcs, clays, pyrophyllite, diatomaceous earth, flours e.g. walnut shell, wheat, redwood, soyabean and cottonseed; magnesium and calcium carbonate, calcium phosphate, sulphur and lime. Specified surface active agents, which may be anionic, cationic or non-ionic, are:-sodium and potassium oleates, amine salts of oleic acid e.g. morpholine oleate and dimethylamine oleate, sulphonated oils e.g. sulphonated fish and castor oils, sulphonated petroleum oils, sulphonated acyclic hydrocarbons, goulac, alkyl naphthalene sodium sulphonate, sodium sulphonated naphthalene formaldehyde condensates, sodium lauryl sulphate, disodium monolauryl phosphate, sorbitol laurate, penta-erythritol monostearate, glycerol monostearate, diglycol oleate, polyethylene oxides and condensates thereof with stearyl alcohol and octyl phenol, polyvinyl alcohols, polyamine salts e.g. acetate, laurylamine hydrochloride, lauryl pyridinium bromide, stearyl trimethyl ammonium bromide, cetyl dimethyl benzyl ammonium chloride, lauryldimethylamine oxide. Compositions containing such surface active agents in proportions of 5 to 15 per cent of the composition are preferred. Other additions are oils and fats e.g. cottonseed oil, olive oil, lard, paraffin oil and hydrogenated vegetable oils; adhesives e.g. gelatin, blood albumin and resins. Concentrated aqueous dispersions containing surface active agents may also include organic liquids such as furfural, methanol, isopropanol, isobutanol, xylol, cresol, cyclohexanone, acetone, methyl ethyl ketone, kerosene, trichloroethylene, dimethylformamide, dimethylacetamide and alkylated naphthalenes. The ureas may also be mixed with fertilizers. The ureas are prepared by methods disclosed in [Class 2 (iii),] [Group IV (b)]. Typical of many of the examples specified are:-1-phenyl-3-methyl urea; 1-(p-chlorophenyl)-3,3-dimethyl urea; 1-phenyl-1,3-dimethyl urea; 1-phenyl-1-methylurea; 1-(p-tolyl)-2-thio-3-allylurea; 1-phenol-2-thio-3,3-dimethyl urea; 1-phenyl-1-methyl-2-thiourea; 1-phenyl-1,3,3-trimethylurea; 1-(m-tolyl)-3,3-dimethylurea; 1-phenyl-2-thio-1,3,3-trimethylurea and 1-(2,4-dichlorophenyl)-3,3-di-methylurea.