Patent GB-1035093-A (GB)
Title: Improvements relating to herbicides
IPC: C07D239/54
Filed: 1962-12-07
Abstract: Compounds of the general formula <FORM:1035093/C2/1> or the corresponding isomeric formula <FORM:1035093/C2/2> wherein R1 represents an alkyl radical containing 1 to 10 carbon atoms, a substituted alkyl radical containing 1 to 8 carbon atoms, an aryl radical containing 5 to 10 carbon atoms, a substituted phenyl radical, an aralkyl radical containing 5 to 13 carbon atoms, a substituted aralkyl radical containing 7 to 13 carbon atoms, an alkenyl radical containing 3 to 8 carbon atoms, a cycloalkyl radical containing 3 to 12 carbon atoms, a cycloalkenyl radical containing 4 to 12 carbon atoms, a substituted cycloalkyl radical containing 3 to 13 carbon atoms, a substituted cycloalkenyl radical containing 4 to 13 carbon atoms, a cycloalkyl alkyl radical containing 4 to 13 carbon atoms, a cycloalkenyl alkyl radical containing 5 to 13 carbon atoms, a (substituted cycloalkyl)alkyl radical containing 5 to 14 carbon atoms or a (substituted cycloalkenyl)alkyl radical containing 5 to 14 carbon atoms; R2 represents a hydrogen, chlorine, fluorine, bromine or iodine atom, a methyl radical, an ethyl radical, a propyl radical, a butyl radical, a methoxy radical, an ethoxy radical, a propoxy radical, a butoxy radical, a nitro radical, an alkoxymethyl radical containing 2 to 6 carbon atoms, a hydroxy alkyl radical containing 1 to 6 carbon atoms, an alkylthio radical containing 1 to 4 carbon atoms, or a methylthiomethyl radical; R21 represents a hydrogen, chlorine, bromine or fluorine atom, a methyl radical or an ethyl radical; R3 represents a hydrogen, chlorine or bromine atom, an alkyl radical containing 1 to 5 carbon atoms, a chloroalkyl radical containing 1 to 4 carbon atoms, a bromoalkyl radical containing 1 to 4 carbon atoms or an alkoxy radical containing 1 to 5 carbon atoms; or R2 and R3 together represent a divalent radical which forms, together with the carbon atoms to which R2 and R3 are attached, a divalent alkylene radical of formula (CH2)n where n is 3, 4 or 5; R31 represents a hydrogen or chlorine atom, an hydroxy radical, an alkoxy radical containing 1 to 6 carbon atoms, an acyloxy radical containing 1 to 6 carbon atoms, a substituted acyloxy radical containing 1 to 6 carbon atoms, a methyl radical or an ethyl radical; and R4 represents a hydrogen, chlorine or bromine atom, an alkyl radical containing 1 to 5 carbon atoms, a substituted alkyl radical containing 1 to 5 carbon atoms, or an alkenyl radical containing 2 to 5 carbon atoms; with the proviso that the molecular weight of the hydrouracil is less than 500, are prepared by methods known for the preparation of hydrouracils, such as (i) addition of suitable compounds across the 5,6-double bond of the corresponding uracil, e.g. alkyl or acyl hypochlorites, hydrogen and halogens; (ii) reaction of an alkyl isocyanate with a substituted b -aminopropionitrile; and (iii) replacement of functional groups in hydrouracils by other groups, e.g. of OH by Cl, MeO, EtO or MeCOO-.  These compounds are herbicides (see Division A5).  Compounds as above in which R1 is C3- 6 alkyl or C5- 10 cycloalkyl or cycloalkenyl; R2 is H, Cl, Br, F, NO2, Me, Et, MeO, -CH2OH or -CH2OEt; R21 is H, Cl or Br; R3 is Cl, Me or Et; or R2 + R3 make (CH2)n where n is 3, 4 or 5; R31 is H, C1- 6 acyloxy or substituted acyloxy or C1- 6 alkoxy; and R4 is hydrogen; with the proviso that when one but not both of R2 and R21 is hydrogen, R31 is hydrogen; and when each of R2, R21 and R31 is hydrogen, R1 is C5- 8 cycloalkyl or cycloalkenyl; are claimed as novel.  5,5 - Dichloro - 6 - hydroxy - 3 - isopropyl - 6-methyl hydrouracil is obtained from 3-isopropyl-6-methyluracil and chlorine in dilute acetic acid.ALSO:Compounds of the general formula <FORM:1035093/A5-A6/1> or the corresponding isomeric formula <FORM:1035093/A5-A6/2> wherein R1 represents an alkyl radical containing 1 to 10 carbon atoms, a substituted alkyl radical containing 1 to 8 carbon atoms, an aryl radical containing 5 to 10 carbon atoms, a substituted phenyl radical, an aralkyl radical containing 5 to 13 carbon atoms, a substituted aralkyl radical containing 7 to 13 carbon atoms, an alkenyl radical containing 3 to 8 carbon atoms, a cycloalkyl radical containing 3 to 12 carbon atoms, a cycloalkenyl radical containing 4 to 12 carbon atoms, a substituted cycloalkyl radical containing 3 to 13 carbon atoms, a substituted cycloalkenyl radical containing 4 to 13 carbon atoms, a cycloalkyl alkyl radical containing 4 to 13 carbon atoms, a cycloalkenyl alkyl radical containing 5 to 13 carbon atoms, a (substituted cycloalkyl)alkyl radical containing 5 to 14 carbon atoms or a (substituted cycloalkenyl)alkyl radical containing 5 to 14 carbon atoms; R2 represents a hydrogen, chlorine, fluorine, bromine or iodine atom, a methyl radical, an ethyl radical, a propyl radical, a butyl radical, a methoxy radical, an ethoxy radical, a propoxy radical, a butoxy radical, a nitro radical, an alkoxymethyl radical containing 2 to 6 carbon atoms, a hydroxy alkyl radical containing 1 to 6 carbon atoms, an alkylthio radical containing 1 to 4 carbon atoms, or a methylthiomethyl radical; R21 represents a hydrogen, chlorine, bromine or fluorine atom, a methyl radical or an ethyl radical; R3 represents a hydrogen, chlorine or bromine atom, an alkyl radical containing 1 to 5 carbon atoms, a chloroalkyl radical containing 1 to 4 carbon atoms, a bromoalkyl radical containing 1 to 4 carbon atoms or an alkoxy radical containing 1 to 5 carbon atoms; or R2 and R3, together represent a divalent radical which forms, together with the carbon atoms to which R2 and R3 are attached, a divalent alkylene radical of formula (CH2)n where n is 3, 4 or 5; R31 represents a hydrogen or chlorine atom, an hydroxy radical, an alkoxy radical containing 1 to 6 carbon atoms, an acyloxy radical containing 1 to 6 carbon atoms, a substituted acyloxy radical containing 1 to 6 carbon atoms, a methyl radical or an ethyl radical; and R4 represents a hydrogen, chlorine or bromine atom, an alkyl radical containing 1 to 5 carbon atoms, a substituted alkyl radical containing 1 to 5 carbon atoms, or an alkenyl radical containing 2 to 5 carbon atoms; with the proviso that the molecular weight of the hydrouracil is less than 500 are used to control the growth of weeds, e.g. in a composition containing additionally (i) a diluent which is at least in part an oil (defined as a liquid immiscible with water and soluble in ether, and boiling at not below 125 DEG C.), with or without a surface-active agent; (ii) a diluent which is at least in part a solid, with or without a surface-active agent; (iii) a surface-active agent and a diluent which is a liquid other than an oil, e.g. water; or (iv) a surface-active agent.  The compositions may be in the form of solutions, dispersions, powders or dusts, granules or pellets, and may contain adhesives, corrosion inhibitors, antifoam agents, dyes, pigments, anticaking agents, hard water stabilisers and other herbicides, e.g. those of Specifications 1,035,092, 1,035,093, 1,035,094, 1,035,095, 1,035,096, 1,035,097, or 1,035,098, or substituted ureas, substituted triazines, phenols, chlorocarboxylic acids and their derivatives, substituted carbamic acid derivatives, maleic hydrazide, inorganic salts, mixed inorganic-organic salts, or other specified herbicides.