Patent GB-914887-A (GB)
Title: New phenyl ureas and thioureas and herbicidal preparations containing them
IPC: C07C275/30
Filed: 1960-02-10
Abstract: The invention comprises compounds of the formula <FORM:0914887/IV (b)/1> where Ar is a phenyl group substituted by halogen or trifluoromethyl which may also contain one or more alkyl or alkoxy groups of up to 4 carbon atoms, nitro groups, halogen atoms or trifluoromethyl groups, X is oxygen or sulphur, R is hydrogen or C3-4 cyanoalkyl, and R1 and R2 are each alkyl of up to 4 carbon atoms, or C3-4 cyanoalkyl, one of R, R1 and R2 being cyanoalkyl; and their salts with acids.  These, and other compounds of the above formula wherein Ar is unsubstituted phenyl or phenyl substituted by one or more alkyl or alkoxy groups of up to 4 carbon atoms, nitro groups, halogen atoms or trifluoromethyl groups, are prepared by known methods, e.g. by reacting ArNCX or ArNR.COCl with HNR1R2. Suitable salt-forming acids are listed.  The above compounds are useful as herbicides (see Group VI).  3-Chloro-4-methoxyphenyl isocyanate, 3-nitro-4-methylphenyl isocyanate and N-methyl-b -cyanoethyl-carbamic acid chloride are prepared by the action of phosgene on o-chloro-p-anisidine, 4-amino-2-nitrotoluene and N-methyl-b -cyanoethylamine hydrochloride respectively.ALSO:Herbicidal compositions comprise a compound of formula <FORM:0914887/VI/1> where Ar is phenyl or phenyl substituted by one or more alkyl or alkoxy groups of up to 4 carbon atoms, nitro groups, halogen atoms or trifluoromethyl groups, X is oxygen or sulphur, R is hydrogen or a C3-4 cyanoalkyl group, and R1 and R2 are each alkyl groups of up to 4 carbon atoms or C3-4 cyanoalkyl groups, one of R, R1 and R2 being cyanoalkyl, or a salt of such a compound with an acid, in admixture with a solid carrier and/or a liquid carrier which, if a hydrocarbon, boils above 100 DEG  C.  The invention also comprises a method for eradicating weeds from an area by treating the area with a compound of the above formula or a salt thereof with an acid. Some of these compounds are claimed as novel (see Group IV (b)). Suitable salt-forming acids are listed.  The carrier in the above compositions may be or contain a substance which influences plant growth.  The compositions may be solutions, e.g. in mineral oils, coal tar oils, vegetable or animal oils, hydrocarbons such as alkylated naphthalenes, tetrahydronaphthalene, xylene mixtures, cyclohexanols, ketones, or chlorohydrocarbons, such as tetrachloroethane, tri-chloroethylene and tri- and tetra-chlorobenzenes.  The compositions may also be in the form of emulsion concentrates, pastes or wettable powders for use by addition of water; the usual emulsifying or dispersing agents are specified.  The compositions may also be in the form of dusting powders with a solid carrier, e.g. talc, kaolin, bentonite, sand, calcium carbonate, calcium phosphate, carbon, cork meal and wood meal.  Other additives such as fatty acids, resins, glue, casein and alginates may be added.  The active compounds may also be incorporated with fertilizers, e.g. superphosphates.  The compositions of the invention may also contain other herbicides, e.g. halophenoxyalkanoic acids, halobenzoic acids or phenylacetic acids, halogenated fatty acids or salts, dodecyl hexamethylene imine or a salt thereof, 1,11-ethylene-2,21-dipyridinium dibromide or a salt thereof, carbamates, thiol carbamates, dithiocarbamic acid esters, s-triazine derivatives, 2-chlorobenzthiazole, 3 - amino - 1,2,4 - triazole, maleic acid hydrazide, 3,5-dimethyl-tetrahydro-1,3,5 - thiadiazine - 2 - thione, pentachlorophenol, dinitrocresol, dinitrobutyl phenol, naphthyl phthalamic acid and methyl isothiocyanate; and insecticidal, fungicidal or nematocidal substances, e.g. halohydrocarbons and phosphoric acid esters.