GB904706A - Isourea derivatives - Google Patents

Abstract

The invention comprises aromatic oalkyl-or substituted alkyl-isoureas of the general formula <FORM:0904706/IV (b)/1> in which Ar stands for an unsubstituted or substituted phenyl radical, Alk stands for an aliphatic hydrocarbon radical which may be substituted and R and R1, which may be the same or different, are hydrogen atoms or alkyl, aryl or cycloalkyl radicals or R and R1, together with the nitrogen atom, may form a ring, which may be interrupted by hetero atoms, said ring being 5- or 6- membered and processes for the preparation thereof wherein (a) an arylimino-halocarbonic acid amide of the general formula <FORM:0904706/IV (b)/2> in which Ar, R and R1 have the same meanings as above and Hal is halogen atom is reacted with an alkanol (b) an arylimino-halocarbonic acid alkyl ester of the general formula <FORM:0904706/IV (b)/3> in which Ar, Alk and Hal have the meanings given above is reacted with ammonia or a primary or secondary amine or (c) an N-arylurea dihalide of the general formula <FORM:0904706/IV (b)/4> wherein Ar, R, R1 and Hal have the meanings given above is reacted with an alkali metal alcoholate. Representative of specific isoureas of which the preparation is described are those of the given general formula in which Ar is phenyl, 4-chlorophenyl, 4-bromophenyl, 2-chloro-4-methylphenyl and 2, 4-dichlorophenyl, Alk is methyl, ethyl, propyl, R is hydrogen, methyl, ethyl and butyl, R1 is methyl, ethyl, propyl and butyl, or the NRR1 group is hetero-cyclic and is piperidine, morpholine or pyrrolidine residue. The products are used as active ingredients in herbicidal compositions (see Group VI). Arylimino-halocarbonic acid imides for use as starting materials are obtained by reacting aryl-isocyanide-dihalides with ammonia or a primary or secondary amine e.g. p-chlorophenyl isocyanide dichloride with dimethylamine. Urea-dihalides for use in the process are obtained by reacting ureas with phosphorous pentachloride.ALSO:Herbicidal compositions comprise as active ingredient a compound of the general formula <FORM:0904706/VI/1> in which Ar stands for an unsubstituted or substituted phenyl radical, Alk stands for an aliphatic hydrocarbon radical which may be substituted and R and R1, which may be the same or different, are hydrogen atoms or alkyl, aryl or cycloalkyl radicals or R and R1, together with the nitrogen atom, may form a ring, which may be interrupted by hetero atoms, said ring being 5- or 6-membered (see Group IV (b)) and a solid or liquid carrier or diluent. A herbicide is described comprising an aqueous dispersion of a mixture of N-phenyl-N1N1-dimethyl - O - methyl - isourea, dimethyl formamide and nonyl phenol-polyglycol ether.