AN N-SUBSTITUTED-PHENYLTERACONIMIDE COMPOUND, HERBICIDAL COMPOSITION, AND METHOD FOR THE DESTRUCTION OF UNDESIRABLE WEEDS

Abstract: An N-substituted-phenylteraconimide compound repre­ sented by the formula wherein X and R are as defined in the disclosure, herbicidal composition and method for the destruction of undesirable weeds. The herbicides comprising the above compounds are capable of selectively controlling undesirable weeds among desirable crop plants.

Description: FIELD OF THE INVENTION This invention relates to a novel compound which exhibits a high herbicidal activity with high selectivity, a novel herbicidal composition comprising as an active ingredient the novel compound which is useful as an effective herbicide for various crops and a method for the destruction of undesirable weeds using the novel herbicidal composition. More particularly, the present invention is concerned with an N-substituted-phenylteraconimide compound, a herbicidal composition comprising the compound and a method for the destruction of undesirable weeds using the herbicidal composition. DESCRIPTION OF THE PRIOR ART To now, a herbicide comprising as an active ingredient an N-substituted-phenyl-3,4,5,6-tetrahydrophthalimide compound is well known as the generally called imide type herbicide to exhibit a high herbicidal activity (see, for example, U.S. Patent No. 3,878,224). However, the known imide type herbicides generally tend to be excellent in herbicidal activity but poor in selectivity. Hence, they are not suitable for practical use. The ideal herbicide should be one which further satisfies the following conditions in addition to the above-stated excellent herbicidal activity and high selectivity. The toxicity of the herbicide to warm-blooded animals must be low. The herbicide is effective even if it is applied any time through the whole period of growth of crop plants. Moreover, after usage, the herbicide decomposes as promptly as possible so that it does not contaminate the soil. However, such an ideal imide type herbicide which satisfies the above conditions is not yet known. OBJECT OF THE INVENTION Under the above-stated current situation, the inventors have made intensive studies to develop a novel imide type herbicide which is free from the drawbacks accompanying the conventional imide type herbicides, which has selective and high herbicidal activity that means complete safety to crop plants and prompt elimination of any unnecessary weeds present therewith, which can be used continuously through the whole period of growth of crop plants. As a result, it has been found that a novel N-substituted-phenylteraconimide compound satisfies the above-mentioned requirements for an improved herbicide, and that the compound, even at a low dosage, is very effective for a wide spectrum of crop plants, such as rice, wheat, corn, soybean and cotton plants. Based on this novel finding, the present invention has been completed. Accordingly, it is an object of the present invention to provide a novel N-substituted-phenylteraconimide compound having a high selectivity as well as a high herbicidal activity. It is another object of the present invention to provide a novel herbicidal composition containing the novel compound. It is a further object of the present invention to provide a method for the destruction of undesirable weeds using the novel herbicidal composition. DESCRIPTION OF THE INVENTION In one aspect of this invention, there is provided an N-substituted-phenylteraconimide compound represented by the formula wherein X represents a hydrogen atom, a fluorine atom or a chlorine atom; and R represents -OR¹ or in which R¹ represents a hydrogen atom, a straight chain or branched alkyl group having up to 8 carbon atoms, a straight chain or branched alkenyl group having up to 8 carbon atoms, an alkynyl group having up to 8 carbon atoms, a cycloalkyl group having up to 8 carbon atoms wherein an oxygen atom, a sulfur atom or a carbonyl group may be substituted for a carbon atom, a straight chain or branched alkyl or alkenyl group having up to 8 carbon atoms and substituted with at least one substituent selected from the group consisting of a halogen atom, a cyano group, a hydroxyl group, an alkoxyl group having up to 8 carbon atoms, an alkylthio group having up to 8 carbon atoms, an epoxy group, an acyl group having up to 8 carbon atoms and an alkoxycarbonyl group having up to 8 carbon atoms, or a 1-methylbenzyl, phenethyl, p-chlorobenzyl, p-methylbenzyl, p-methoxybenzyl, or cinnamyl group, R² represents a hydrogen atom or a straight chain or branched alkyl group having up to 8 carbon atoms, and R³ and R⁴ each independently represent a hydrogen atom, a straight chain or branched alkyl group having up to 8 carbon atoms, a straight chain or branched alkenyl group having up to 8 carbon atoms, an alkynyl group having up to 8 carbon atoms, an alkoxyl group having up to 8 carbon atoms, an alkoxyalkyl group having up to 8 carbon atoms, an alkoxycarbonylalkyl group having up to 8 carbon atoms, a cycloalkyl group having up to 8 carbon atoms, a hydroxyalkyl group having up to 8 carbon atoms, a cyanoalkyl group having up to 8 carbon atoms, an aralkyl group having up to 9 carbon atoms or an aryl group having up to 8 carbon atoms, or R³ and R⁴ are directly bonded with each other, thereby forming with the nitrogen atom bonded therewith a heterocyclic ring group having up to 7 carbon atoms, in the skeleton of which an oxygen atom is contained or not contained. The characteristic feature of the compound of the present invention resides in that it has, in its molecular structure, an isopropylidene group as a substituent, as opposed to the conventional herbicides. It is quite unexpected that the introduction of the substituent enables the compound of the present invention to provide a herbicide which has a largely improved selectivity, such a high selectivity being never attained by the conventional imide type herbicides, and effectively eliminates undesirable weeds present with various crop plants by either preemergence or postemergence application. Specific embodiments of compounds of the present invention are represented by the above mentioned formula (I), wherein X represents a fluorine atom, and R¹ represents a straight chain or branched alkyl group having up to 8 carbon atoms, a straight chain or branched alkenyl group having up to 8 carbon atoms or an alkynyl group having up to 8 carbon atoms, or wherein X represents a clorine atom and R¹ represents a straight chain or branched alkyl group having up to 8 carbon atoms, a straight chain or branched alkenyl group having up to 8 carbon atoms or an alkynyl group having up to 8 carbon atoms, or wherein X represents a fluorine atom, R² represents a methyl group, and R³ and R⁴ are directly bonded with each other, thereby forming with a nitrogen atom bonded therewith a heterocyclic ring group, in the skeleton of which an oxygen atom is contained or not contained, or R³ represents a straight chain or branched alkyl group having up to 8 carbon atoms, a straight chain or branched alkenyl group having up to 8 carbon atoms, an alkynyl group having up to 8 carbon atoms, an alkoxyl group having up to 8 carbon atoms or a cycloalkyl group having up to 8 carbon atoms, and R⁴ represents a hydrogen atom, a straight chain or branched alkyl group having up to 8 carbon atoms, a straight chain or branched alkenyl group having up to 8 carbon atoms or an alkynyl group having up to 8 carbon atoms, or wherein X represents a hydrogen atom, R² represents a methyl group, and R³ and R⁴ are directly bonded with each other, thereby forming with the nitrogen atom bonded therewith a heterocyclic ring group, in the skeleton of which an oxygen atom is contained or not contained, or R³ represents a straight chain or branched alkyl group having up to 8 carbon atoms, a straight chain or branched alkenyl group having up to 8 carbon atoms, an alkynyl group having up to 8 carbon atoms, an alkoxyl group having up to 8 carbon atoms or a cycloalkyl group having up to 8 carbon atoms, and R⁴ represents a hydrogen atom, a straight chain or branched alkyl group having up to 8 carbon atoms, a straight chain or branched alkenyl group having up to 8 carbon atoms or an alkynyl group having up to 8 carbon atoms, or wherein X represents a fluorine atom, and R¹ represents an alkoxyalkyl group having up to 8 carbon atoms. In R¹ of the above formula (I), the straight chain or branched alkyl group having up to 8 carbon atoms may be, for example, methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, iso-butyl, n-amyl, iso-amyl, n-hexyl, n-heptyl or n-octyl. The straight chain or branched alkenyl group having up to 8 carbon atoms may be, for example, allyl, crotyl, methallyl, 1-methyl-2-propenyl or 3-methyl-2-butenyl. The alkynyl group having up to 8 carbon atoms may be, for example, propargyl, 1-methyl-2-propynyl, 1,1-dimethylpropynyl or 2-butynyl. The cycloalkyl group having up to 8 carbon atoms may be, for example, cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl. The cycloalkyl group having up to 8 carbon atoms wherein a carbon atom thereof is substituted with an oxygen atom, a sulfur atom or a carbonyl group may be, for example, 2-tetrahydropyranyl, 2-oxocyclopentyl, 2-oxocyclohexyl or 2-tetrahydrothiopyran. The substituted straight chain or branched alkyl or alkenyl group may be, for example, 2-chloroethyl, 2-bromoethyl, 3-chloro-2-propenyl (cys isomer), 3-chloro-2-propenyl (trans isomer), 3-chloro-2-butenyl (cis isomer), 3-chloro-2-butenyl (trans isomer), 2-chloro-2-propenyl, 2,2,2-trifluoroethyl, 2-chloropropyl, cyanomethyl, 1-cyanoethyl, 2-cyanoethyl, 2-hydroxyethyl, 2-hydroxypropyl, methoxyethyl, ethoxyethyl, methoxymethyl, ethoxymethyl, propoxymethyl, methylthiomethyl, ethylthiomethyl, methylthioethyl, ethylthioethyl, 2,3-epoxypropyl, 2,3-epoxybutyl, benzyl, 1-methylbenzyl, phenethyl, p-chlorobenzyl, p-methylbenzyl, p-methoxybenzyl, cinnamyl, phenacyl, acetonyl, 2-oxobutyl, methoxycarbonylmethyl, ethoxycarbonylmethyl, 1-methoxycarbonylethyl, 1-ethoxycarbonylethyl, 2-methoxycarbonylethyl, 1-methyl-1-methoxycarbonylethyl, 1-methyl-1-ethoxycarbonylethyl, 3-methoxycarbonyl-2-propenyl, 3-ethoxycarbonyl-2-propenyl, 2,2-dimethoxyethyl, 2,2-diethoxyethyl, 1,1-dimethoxyethyl, 1-methoxy-1-methoxycarbonylmethyl or 1-methoxy-1-ethoxycarbonylmethyl. In R² of the formula (I), the straight chain or branched alkyl group having up to 8 carbon atoms may be, for example, those as mentioned above with respect to R¹. In R³ and R⁴ of the formula (I), the straight chain or branched alkyl group having up to 8 carbon atoms may be, for example, methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, iso-butyl, n-amyl, iso-amyl or n-hexyl. The straight chain or branched alkenyl group having up to 8 carbon atoms may be, for example, allyl, crotyl, methallyl or 1-methyl-2-propenyl. The alkynyl group having up to 8 carbon atoms may be, for example, those as mentioned above with respect to R¹. The alkoxyl group having up to 8 carbon atoms may be, for example, methoxy, ethoxy, n-propoxy, iso-propoxy, n-butoxy, iso-butoxy or sec-butoxy. The alkoxyalkyl, alkoxycarbonylalkyl, cycloalkyl, hydroxyalkyl and cyanoalkyl groups respectively having up to 8 carbon atoms may be, for example, those as mentioned above with respect to R¹, respectively. The aralkyl group having up to 9 carbon atoms may be, for example, benzyl, 1-methylbenzyl or phenethyl. The aryl group having up to 8 carbon atoms may be, for example, phenyl, p-chlorophenyl or p-tolyl. In the above formula (I), when either of R³ and R⁴ represents a straight chain or branched alkyl group having up to 8 carbon atoms and the other represents a straight chain or branched alkyl group having up to 8 carbon atoms, an alkoxyl group having up to 8 carbon atoms or an alkoxyalkyl group having up to 8 carbon atoms, they have their respective free terminal ends or they are directly bonded with each other, thereby forming with the nitrogen atom bonded therewith a heterocyclic ring group having up to 7 carbon atoms. The heterocyclic ring group formed by R³, R⁴ and the nitrogen atom may be, for example, piperidino, morpholino, pipecolino, pyrrolidino or oxazolidino. In R¹ of the above formula (I), the alkyl group preferablly has up to 6 carbon atoms; the alkenyl, alkynyl, alkoxy and alkylthio groups preferably have up to 4 carbon atoms, respectively; the cycloalkyl group preferably has 3 to 6 carbon atoms; the acyl group preferably has 2 to 7 carbon atoms; the aromatic hydrocarbon group preferably has 6 to 8 carbon atoms; and the alkoxycarbonyl group preferably has 2 to 5 carbon atoms. In R² of the formula (I), the alkyl group preferably has up to 6 carbon atoms. In R³ and R⁴ of the formula (I), the alkyl group preferably has up to 6 carbon atoms; the alkenyl group preferably has 3 to 4 carbon atoms; the alkynyl and alkoxycarbonylalkyl groups preferably has 3 to 5 carbon atoms, respectively; the alkoxy group preferably has up to 4 carbon atoms; the alkoxyalkyl group preferably has 2 to 4 carbon atoms; the cycloalkyl group preferably has 3 to 6 carbon atoms; the hydroxyalkyl and cyanoalkyl groups preferably has 2 to 4 carbon atoms, respectively; the aralkyl group preferably has 7 to 9 carbon atoms; and the aryl group preferably has 6 to 8 carbon atoms. As specific examples of the compound of the present invention represented by the general formula (I), there may be mentioned: N-(2,4-dichloro-5-hydroxyphenyl)teraconimide, N-(2,4-dichloro-5-methoxyphenyl)teraconimide, N-(2,4-dichloro-5-ethoxyphenyl)teraconimide, N-(2,4-dichloro-5-n-propoxyphenyl)teraconimide, N-(2,4-dichloro-5-n-butoxyphenyl)teraconimide, N-(2,4-dichloro-5-n-hexyloxyphenyl)teraconimide, N-(2,4-dichloro-5-n-heptyloxyphenyl)teraconimide, N-(2,4-dichloro-5-n-octyloxyphenyl)teraconimide, N-(2,4-dichloro-5-isopropoxyphenyl)teraconimide, N-(2,4-dichloro-5-isobutoxyphenyl)teraconimide, N-(2,4-dichloro-5-sec-butoxyphenyl)teraconimide, N-(2,4-dichloro-5-allyloxyphenyl)teraconimide, N-(2,4-dichloro-5-crotyloxyphenyl)teraconimide, N-(2,4-dichloro-5-methallyloxyphenyl)teraconimide, N-[2,4-dichloro-5-(1-methylallyloxy)phenyl]teraconimide, N-(2,4-dichloro-5-propargyloxyphenyl)teraconimide, N-(2,4-dichloro-5-cyclopropyloxyphenyl)teraconimide, N-(2,4-dichloro-5-cyclopentyloxyphenyl)teraconimide, N-(2,4-dichloro-5-cyclohexyloxyphenyl)teraconimide, N-[2,4-dichloro-5-(2-fluoroethyloxy)phenyl]teraconimide, N-[2,4-dichloro-5-(2-chloroethyloxy)phenyl]teraconimide, N-[2,4-dichloro-5-(2-bromoethyloxy)phenyl]teraconimide, N-[2,4-dichloro-5-(2,2,2-trifluoroethyloxy)phenyl]teraconimide, N-(2,4-dichloro-5-trifluoromethyloxyphenyl)teraconimide, N-(2,4-dichloro-5-difluoromethyloxyphenyl)teraconimide, N-[2,4-dichloro-5-(2-cyanoethyloxy)phenyl]teraconimide, N-[2,4-dichloro-5-(1-cyanoethyloxy)phenyl]teraconimide, N-(2,4-dichloro-5-cyanomethyloxyphenyl)teraconimide, N-[2,4-dichloro-5-(2-hydroxyethyloxy)phenyl]teraconimide, N-[2,4-dichloro-5-(2-methoxyethyloxy)phenyl]teraconimide, N-[2,4-dichloro-5-(2-ethoxyethyloxy)phenyl]teraconimide, N-[2,4-dichloro-5-(2-isopropoxyethyloxy)phenyl]teraconimide, N-[2,4-dichloro-5-(2-methylthioethyloxy)phenyl]teraconimide, N-[2,4-dichloro-5-(2-ethylthioethyloxy)phenyl]teraconimide, N-[2,4-dichloro-5-(2,3-epoxypropyloxy)phenyl]teraconimide, N-[2,4-dichloro-5-(α-methylbenzyloxy)phenyl]teraconimide, N-(2,4-dichloro-5-benzyloxyphenyl)teraconimide, N-(2,4-dichloro-5-phenethyloxyphenyl)teraconimide, N-[2,4-dichloro-5-(p-chlorobenzyloxy)phenyl]teraconimide, N-[2,4-dichloro-5-(1-methoxycarbonylethyloxy)phenyl]teraconimide, N-[2,4-dichloro-5-(1-ethoxycarbonylethyloxy)phenyl]teraconimide, N-(2,4-dichloro-5-methoxycarbonylmethyloxyphenyl)teraconimide, N-(2,4-dichloro-5-ethoxycarbonylmethyloxyphenyl)teraconimide, N-(2,4-dichloro-5-methylcarbonylmethyloxyphenyl)teraconimide, N-(2,4-dichloro-5-phenylcarbonylmethyloxyphenyl)teraconimide, N-(2,4-dichloro-5-n-amyloxyphenyl)teraconimide, N-(2,4-dichloro-5-isoamyloxyphenyl)teraconimide, N-[2,4-dichloro-5-(1-methoxy-1-methoxycarbonylmethyloxy)phenyl]teraconimide, N-(4-chloro-5-hydroxyphenyl)teraconimide, N-(4-chloro-5-methoxyphenyl)teraconimide, N-(4-chloro-5-ethoxyphenyl)teraconimide, N-(4-chloro-5-n-propoxyphenyl)teraconimide, N-(4-chloro-5-n-butoxyphenyl)teraconimide, N-(4-chloro-5-isopropoxyphenyl)teraconimide, N-(4-chloro-5-isobutoxyphenyl)teraconimide, N-(4-chloro-5-sec-butoxyphenyl)teraconimide, N-(4-chloro-5-allyloxyphenyl)teraconimide, N-(4-chloro-5-crotyloxyphenyl)teraconimide, N-(4-chloro-5-methallyloxyphenyl)teraconimide, N-[4-chloro-5-(1-methylallyloxy)phenyl]teraconimide, N-(4-chloro-5-cyclohexyloxyphenyl)teraconimide, N-[4-chloro-5-(2-fluoroethyloxy)phenyl]teraconimide, N-[4-chloro-5-(2-chloroethyloxy)phenyl]teraconimide, N-[4-chloro-5-(2-bromoethyloxy)phenyl]teraconimide, N-[4-chloro-5-(2,2,2-trifluoroethyloxy)phenyl]teraconimide, N-(4-chloro-5-trifluoromethyloxyphenyl)teraconimide, N-(4-chloro-5-difluoromethyloxyphenyl)teraconimide, N-[4-chloro-5-(2-cyanoethyloxy)phenyl]teraconimide, N-[4-chloro-5-(1-cyanoethyloxy)phenyl]teraconimide, N-(4-chloro-5-cyanomethyloxyphenyl)teraconimide, N-[4-chloro-5-(2-hydroxyethyloxy)phenyl]teraconimide, N-[4-chloro-5-(2-methoxyethyloxy)phenyl]teraconimide, N-[4-chloro-5-(2-ethoxyethyloxy)phenyl]teraconimide, N-[4-chloro-5-(2-isopropoxyethyloxy)phenyl]teraconimide, N-[4-chloro-5-(2-methylthioethyloxy)phenyl]teraconimide, N-[4-chloro-5-(2-ethylthioethyloxy)phenyl]teraconimide, N-[4-chloro-5-(2,3-epoxypropyloxy)phenyl]teraconimide, N-[4-chloro-5-(α-methylbenzyloxy)phenyl]teraconimide, N-(4-chloro-5-benzyloxyphenyl)teraconimide, N-(4-chloro-5-phenethyloxyphenyl)teraconimide, N-[4-chloro-5-(p-chlorobenzyloxy)phenyl]teraconimide, N-[4-chloro-5-(1-methoxycarbonylethyloxy)phenyl]teraconimide, N-[4-chloro-5-(1-ethoxycarbonylethyloxy)phenyl]teraconimide, N-(4-chloro-5-methoxycarbonylmethyloxyphenyl)teraconimide, N-(4-chloro-5-ethoxycarbonylmethyloxyphenyl)teraconimide, N-(4-chloro-5-methylcarbonylmethyloxyphenyl)teraconimide, N-(4-chloro-5-phenylcarbonylmethyloxyphenyl)teraconimide, N-(4-chloro-5-n-amyloxyphenyl)teraconimide, N-(4-chloro-5-isoamyloxyphenyl)teraconimide, N-[4-dichloro-5-(1-methoxy-1-methoxycarbonylmethyloxy)phenyl]teraconimide, N-(4-chloro-5-propargyloxyphenyl)teraconimide, N-(4-chloro-5-cyclopropyloxyphenyl)teraconimide, N-(4-chloro-5-cyclopentyloxyphenyl)teraconimide, N-(2-fluoro-4-chloro-5-hydroxyphenyl)teraconimide, N-(2-fluoro-4-chloro-5-methoxyphenyl)teraconimide, N-(2-fluoro-4-chloro-5-ethoxyphenyl)teraconimide, N-(2-fluoro-4-chloro-5-n-propoxyphenyl)teraconimide, N-(2-fluoro-4-chloro-5-n-butoxyphenyl)teraconimide, N-(2-fluoro-4-chloro-5-isopropoxyphenyl)teraconimide, N-(2-fluoro-4-chloro-5-isobutoxyphenyl)teraconimide, N-(2-fluoro-4-chloro-5-sec-butoxyphenyl)teraconimide, N-(2-fluoro-4-chloro-5-allyloxyphenyl)teraconimide, N-(2-fluoro-4-chloro-5-crotyloxyphenyl)teraconimide, N-(2-fluoro-4-chloro-5-methallyloxyphenyl)teraconimide, N-[2-fluoro-4-chloro-5-(1-methylallyloxy)phenyl]teraconimide, N-(2-fluoro-4-chloro-5-propargyloxyphenyl)teraconimide, N-(2-fluoro-4-chloro-5-cyclopropyloxyphenyl)teraconimide, N-(2-fluoro-4-chloro-5-cyclopentyloxyphenyl)teraconimide, N-(2-fluoro-4-chloro-5-cyclohexyloxyphenyl)teraconimide, N-[2-fluoro-4-chloro-5-(2-fluoroethyloxy)phenyl]teraconimide, N-[2-fluoro-4-chloro-5-(2-chloroethyloxy)phenyl]teraconimide, N-[2-fluoro-4-chloro-5-(2-bromoethyloxy)phenyl]teraconimide, N-[2-fluoro-4-chloro-5-(2,2,2-trifluoroethyloxy)phenyl]teraconimide, N-(2-fluoro-4-chloro-5-trifluoromethyloxyphenyl)teraconimide, N-(2-fluoro-4-chloro-5-difluoromethyloxyphenyl)teraconimide, N-[2-fluoro-4-chloro-5-(2-cyanoethyloxy)phenyl]teraconimide, N-[2-fluoro-4-chloro-5-(1-cyanoethyloxy)phenyl]teraconimide, N-(2-fluoro-4-chloro-5-cyanomethyloxyphenyl)teraconimide, N-[2-fluoro-4-chloro-5-(2-hydroxyethyloxy)phenyl]teraconimide, N-[2-fluoro-4-chloro-5-(2-methoxyethyloxy)phenyl]teraconimide, N-[2-fluoro-4-chloro-5-(2-ethoxyethyloxy)phenyl]teraconimide, N-[2-fluoro-4-chloro-5-(2-isopropoxyethyloxy)phenyl]teraconimide, N-[2-fluoro-4-chloro-5-(2,3-epoxypropyloxy)phenyl]teraconimide, N-[2-fluoro-4-chloro-5-(α-methylbenzyloxy)phenyl]teraconimide, N-(2-fluoro-4-chloro-5-benzyloxyphenyl)teraconimide, N-(2-fluoro-4-chloro-5-phenethyloxyphenyl)teraconimide, N-[2-fluoro-4-chloro-5-(p-chlorobenzyloxy)phenyl]teraconimide, N-[2-fluoro-4-chloro-5-(1-methoxycarbonylethyloxy)phenyl]teraconimide, N-[2-fluoro-4-chloro-5-(1-ethoxycarbonylethyloxy)phenyl]teraconimide, N-(2-fluoro-4-chloro-5-methoxycarboxylmethyloxyphenyl)teraconimide, N-(2-fluoro-4-chloro-5-ethoxycarbonylmethyloxyphenyl)teraconimide, N-(2-fluoro-4-chloro-5-methylcarbonylmethyloxyphenyl)teraconimide, N-(2-fluoro-4-chloro-5-phenylcarbonylmethyloxyphenyl)teraconimide, N-(2-fluoro-4-chloro-5-n-amyloxyphenyl)teraconimide, N-(2-fluoro-4-chloro-5-isoamyloxyphenyl)teraconimide, N-[2-fluoro-4-chloro-5-(1-methoxy-1-methoxycarbonylmethyloxy)phenyl]teraconimide, N-(2-fluoro-4-chloro-5-methoxymethoxyphenyl)teraconimide, N-[5-[1-(methylcarbamoyl)ethylamino]-2,4-dichlorophenyl]teraconimide, N-[5-[1-(methylcarbamoyl)ethylamino]-4-chlorophenyl]teraconimide, N-[1-[1-(methylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(ethylcarbamoyl)ethylamino]-2,4-dichlorophenyl]teraconimide, N-[5-[1-(ethylcarbamoyl)ethylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(ethylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(n-propylcarbamoyl)ethylamino]-2,4-dichlorophenyl]teraconimide, N-[5-[1-(n-propylcarbamoyl)ethylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(n-propylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(iso-propylcarbamoyl)ethylamino]-2,4-dichlorophenyl]teraconimide, N-[5-[1-(iso-propylcarbamoyl)ethylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(iso-propylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(n-butylcarbamoyl)ethylamino]-2,4-dichlorophenyl]teraconimide, N-[5-[1-(n-butylcarbamoyl)ethylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(n-butylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(sec-butylcarbamoyl)ethylamino]-2,4-dichlorophenyl]teraconimide, N-[5-[1-(sec-butylcarbamoyl)ethylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(sec-butylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(iso-butylcarbamoyl)ethylamino]-2,4-dichlorophenyl]teraconimide, N-[5-[1-(iso-butylcarbamoyl)ethylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(iso-butylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(tert-butylcarbamoyl)ethylamino]-2,4-dichlorophenyl]teraconimide, N-[5-[1-(tert-butylcarbamoyl)ethylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(tert-butylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(n-amylcarbamoyl)ethylamino]-2,4-dichlorophenyl]teraconimide, N-[5-[1-(n-amylcarbamoyl)ethylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(n-amylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(iso-amylcarbamoyl)ethylamino]-2,4-dichlorophenyl]teraconimide, N-[5-[1-(iso-amylcarbamoyl)ethylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(iso-amylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(cyclopropylcarbamoyl)ethylamino]-2,4-dichlorophenyl]teraconimide, N-[5-[1-(cyclopropylcarbamoyl)ethylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(cyclopropylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(cyclobutylcarbamoyl)ethylamino]-2,4-dichlorophenyl]teraconimide, N-[5-[1-(cyclobutylcarbamoyl)ethylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(cyclobutylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(cyclopentylcarbamoyl)ethylamino]-2,4-dichlorophenyl]teraconimide, N-[5-[1-(cyclopentylcarbamoyl)ethylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(cyclopentylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(cyclohexylcarbamoyl)ethylamino]-2,4-dichlorophenyl]teraconimide, N-[5-[1-(cyclohexylcarbamoyl)ethylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(cyclohexylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(allylcarbamoyl)ethylamino]-2,4-dichlorophenyl]teraconimide, N-[5-[1-(allylcarbamoyl)ethylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(allylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(crotylcarbamoyl)ethylamino]-2,4-dichlorophenyl]teraconimide, N-[5-[1-(crotylcarbamoyl)ethylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(crotylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(propargylcarbamoyl)ethylamino]-2,4-dichlorophenyl]teraconimide, N-[5-[1-(propargylcarbamoyl)ethylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(propargylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(1,1-dimethylpropargylcarbamoyl)ethylamino]-2,4-dichlorophenyl]teraconimide, N-[5-[1-(1,1-dimethylpropargylcarbamoyl)ethylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(1,1-dimethylpropargylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(N-methoxy-N-methylcarbamoyl)ethylamino]-2,4-dichlorophenyl]teraconimide, N-[5-[1-(N-methoxy-N-methylcarbamoyl)ethylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(N-methoxy-N-methylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(N-ethoxy-N-ethylcarbamoyl)ethylamino]-2,4-dichlorophenyl]teraconimide, N-[5-[1-(N-ethoxy-N-ethylcarbamoyl)ethylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(N-ethoxy-N-ethylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(N-methoxy-N-ethylcarbamoyl)ethylamino]-2,4-dichlorophenyl]teraconimide, N-[5-[1-(N-methoxy-N-ethylcarbamoyl)ethylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(N-methoxy-N-ethylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(N-propoxy-N-propylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(N,N-dimethylcarbamoyl)ethylamino]-2,4-dichlorophenyl]teraconimide, N-[5-[1-(N,N-dimethylcarbamoyl)ethylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(N,N-dimethylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(N,N-diethylcarbamoyl)ethylamino]-2,4-dichlorophenyl]teraconimide, N-[5-[1-(N,N-diethylcarbamoyl)ethylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(N,N-diethylcarbamoyl)ethylamino]-2,4-dichlorophenyl]teraconimide, N-[5-[1-(N,N-diethylcarbamoyl)ethylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(N,N-diethylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(N,N-diallylcarbamoyl)ethylamino]-2,4-dichlorophenyl]teraconimide, N-[5-[1-(N,N-diallylcarbamoyl)ethylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(N,N-diallylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(N,N-diisopropylcarbamoyl)ethylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(N,N-diisopropylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(morpholinocarbamoyl)ethylamino]-2,4-dichlorophenyl]teraconimide, N-[5-[1-(morpholinocarbamoyl)ethylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(morpholinocarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(piperidinocarbamoyl)ethylamino]-2,4-dichlorophenyl]teraconimide, N-[5-[1-(piperidinocarbamoyl)ethylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(piperidinocarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(methoxyethylcarbamoyl)ethylamino]-2,4-dichlorophenyl]teraconimide, N-[5-[1-(methoxyethylcarbamoyl)ethylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(methoxyethylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(ethoxyethylcarbamoyl)ethylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(ethoxyethylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(N-methoxycarbamoyl)ethylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(N-methoxycarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(N-ethoxycarbamoyl)ethylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(N-ethoxycarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(N-iso-propoxycarbamoyl)ethylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(N-iso-propoxycarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(N-n-butoxycarbamoyl)ethylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(N-n-butoxycarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(ethoxycarbonylmethylcarbamoyl)ethylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(ethoxycarbonylmethylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(iso-butylcarbamoyl)methylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(iso-butylcarbamoyl)methylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(morpholinocarbamoyl)methylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(morpholinocarbamoyl)methylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(iso-butylcarbamoyl)propylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(iso-butylcarbamoyl)propylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(morpholinocarbamoyl)propylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(morpholinocarbamoyl)propylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(iso-butylcarbamoyl)butylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(morpholinocarbamoyl)butylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(cyclohexylcarbamoyl)butylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(hydroxyethylcarbamoyl)ethylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(hydroxyethylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(cyanomethylcarbamoyl)ethylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(cyanomethylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(2-cyanoethylcarbamoyl)ethylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(2-cyanoethylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(phenylcarbamoyl)ethylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(phenylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(benzylcarbamoyl)ethylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(benzylcarbamoyl)ethylamino]-2-fluoro-4-chloropbenyl]teraconimide, N-[5-[1-(N-ethyl-N-n-propylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(N-ethyl-N-n-propylcarbamoyl)ethylamino]-4-chlorophenyl]teraconimide, N-[5-[1-(N-methoxy-N-methylcarbamoyl)propylamino]-2-fluoro-4-chlorophenyl]teraconimide and N-[5-[1-(N-methoxy-N-methylcarbamoyl)propylamino]-4-chlorophenyl]teraconimide. All of the above compounds are novel compounds which have not been disclosed in any literature. They may be prepared according to, for example, Method A to Method C, as described below. Method A Reaction process : wherein X and R are as defined hereinbefore. In this method, a substituted aniline represented by the formula (II) is reacted with teraconic acid anhydride either in the absence of a solvent or in the presence of an inert solvent having a high boiling point such as acetic acid, o-dichlorobenzene and the like at a temperature of from-about 100 ° to 200 °C, preferably from about 120 ° to 170 °C, for about 2 to 10 hours to obtain a compound represented by the formula (I) according to the present invention. The molar ratio of the compound (II) to teraconic acid anhydride is preferably about 1. This process, which involves two reactions, i.e. formation of an amide and dehydration-ring closure to an imide, may also be effected by other conditions. That is, the first step of amidation is conducted under moderate conditions, i.e. at a temperature of from room temperature to about 100 °C, in the presence of a solvent. Then, the solvent is removed and the second step of dehydration-ring closure is conducted using a dehydrating agent under the moderate conditions to form an imide. The molar ratio of the dehydrating agent to the amide is preferably in the range of from about 1:1 to 2:1. Suitable solvents to be used in the above first step include ether type solvents such as tetrahydrofuran, dioxane; aromatic solvents such as toluene; halogenated hydrocarbon type solvents such as chloroform; and aprotic polar solvents such as N,N-dimethylformamide, dimethylsulfoxide. The dehydrating agent to be used in the above second process includes acetic acid anhydride/sodium acetate or thionyl chloride. Method B Reaction process : wherein X and R¹ are as defined hereinbefore, Z represents a halogen atom and M represents an alkali metal atom. In this method, an N-substituted-phenylteraconimide compound represented by the formula (III) is reacted with a halide represented by the formula (IV) in a solvent such as acetonitrile, dimethylformamide, dimethylacetamide or dimethylsulfoxide at a temperature of from room temperature to 100 °C, preferably from 50 ° to 80 °C, for about 2 to 10 hours to obtain a compound represented by the formula (I-a) according to the present invention. The molar ratio of the compound (III) to the compound (IV) is preferably in the range of from about 1:1 to 1:1.5. Besides the above-mentioned solvents, there may also preferably be employed tetrahydrofuran in which 18-crown-6 is contained as a phase-transfer catalyst. Method C Reaction process : wherein X, R², R³, R⁴ and Z are as defined hereinbefore. In this method, an aniline derivative represented by the formula (VI) is reacted with a carboxamide derivative represented by the formula (VII) at a temperature of from 50 ° to 250 °C for about 2 to 10 hours to obtain a compound represented by the formula (I-b) according to the present invention. The molar ratio of the compound (VI) to the compound (VII) is preferably 1. This reaction is conducted either in a solvent or not in a solvent, in the presence of a basic compound such as sodium bicarbonate, potassium bicarbonate, sodium carbonate, potassium carbonate, sodium acetate or sodium hydroxide, and either in the absence or in the presence of an iodide such as sodium iodide or potassium iodide. As the solvent to be used in this method, there may be mentioned o-dichlorobenzene, dimethylsulfoxide, sulfolane, N,N-dimethylformamide, benzene, toluene, acetone 2-butanone, tetrahydrofuran or acetonitrile, dioxane. The above Methods A to C are illustrative of preferred processes for producing the compounds of the present invention. It should be understood that these methods are not intended to limit the process for producing the compound of the present invention. The compounds of the present invention may be produced by various methods which are modifications of conventionally known methods for producing similar compounds. The herbicidal activity of the compound of the present invention is illustrated hereinbelow with respect to the prevention and elimination of the weeds which grow on paddy fields. The compound of the present invention can be effectively applied to paddy fields in a prolonged period of time including the pre-transplantaiton and post-transplantation periods of rice plant seedlings. Especially, the compound is useful to effectively and promptly destroy annual weeds in paddy fields. Moreover, the compound of the present invention has no significant phytotoxicity to rice plants when it is applied in such an effective amount that the weeds are destroyed effectively. Further, the compound of the present invention also exhibits high herbicidal activities to perennial weeds on paddy fields, such as "Hotarui" ( Scirpus juncoides ) or flat sedge. The compound of the present invention exhibits extremely high herbicidal activities not only to the paddy field weeds but also to the upland weeds. The compound of the present invention exhibits high herbicidal activities even in a small dosage to a variety of weeds, for example, broad-leaved weeds such as livid amaranth, smartweed, cocklebur, common chickweed or bind weed, and the weeds belonging to the family Gramineae such as crabgrass, goosegrass, green foxtail or annual poa. The characteristic feature of the compound of the present invention resides in that the compound exhibits, in both of the preemergence and postemergence applications, an excellent selectivity for not only broad-leaved crop plants such as soybean or cotton but also crop plants belonging to the family Gramineae such as rice, corn or wheat plants. Further, due to its wide applicability and excellent herbicidal activities, the compound of the present invention is also useful as an effective herbicide for a pasture, an orchard, a lawn and a noncropland. In practical application of the present compound as a herbicide, it may be applied as such, or may be formulated into various types of preparations, such as wettable powder, emulsifiable concentrate or granule, dust. Hence, in another aspect of the present invention, there is provided a herbicidal composition which comprises as an active ingredient a herbicidally effective amount of a compound represented by the formula wherein R and X are as defined above. The term "a herbicidally effective amount" used herein is intended to mean an amount required under the environmental conditions in order to effectively control weeds, that is, the weeds are severely injured so as not to be able to recover from the application of the compound or are killed, and no substantial injury is caused to the crops. As the solid carrier to be used for formulating the present compound into the above-described various preparations, there may be mentioned mineral powder (e.g. kaolin, bentonite, clay, montmorillonite, talc, diatomite, mica, vermiculite, gypsum, calcium carbonate or apatite, vegetable powder (e.g. soybean meal, wheat flour, wood meal, tobacco powder, starch or crystalline cellulose), high polymer compounds (e.g. petroleum resin, polyvinyl chloride or ketone resin and, further, alumina and waxes. As the liquid carrier, there may be mentioned, for example, alcohols such as methanol, ethanol, butanol, ethylene glycol or benzyl alcohol, aromatic hydrocarbons (such as toluene, benzene or xylene), chlorinated hydrocarbons (such as chloroform, carbon tetrachloride or monochlorobenzene), ethers (such as dioxane or tetrahydrofuran, ketones (such as acetone, methyl ethyl ketone or cyclohexanone), esters (such as ethyl acetate or butyl acetate), acid amids (such as N,N-dimethylacetamide), nitriles (such as acetonitrile), ether alcohols (such as ethylene glycol ethyl ether and water. As the surface active agent to be used to effect, for example emulsifying, dispersing or spreading for the present compound, there may be mentioned nonionic, anionic, cationic and amphoteric ones. Specific examples of the surface active agent which can be employed in the present invention are a polyoxyethylene alkyl ether, a polyoxyethylene alkylaryl ether, a polyoxyethylene fatty acid ester, a sorbitan fatty acid ester, a polyoxyethylene sorbitan fatty acid ester, an oxyethylene polymer, an oxypropylene polymer, a polyoxyethylene alkyl phosphate, a fatty acid salt, an alkyl sulfate salt, an alkyl sulfonate salt, an alkyl aryl sulfonate salt, an alkyl phosphate salt, a polyoxyethylene alkyl sulfate, a quaternary ammonium salt and an oxyalkylamine. The surface active agent which can be used in the present invention is by no means limited to the above surface active agents. Further, according to need, gelatin, casein, sodium alginate, starch, agar, polyvinyl alcohol and the like may be used as an auxiliary additive in the present invention. The content of the compound (I) of the present invention in the herbicidal composition may vary depending on the type of the composition and the purpose for which the composition is designed, however, be generally from about 0.05 to 95 % by weight, preferably about 5 to 75 % by weight based on the total weight of the composition. Moreover, in order to improve the effect as a herbicide, the compound of the present invention may be mixed with other herbicidally active ingredients and, in some cases, a synergistic effect is expectable. For example, the following ingredients may be mixed with the compound of the present invention. (A) Phenoxy type herbicide such as 2,4-dichlorophenoxyacetic acid; 2-methyl-4-chlorophenoxyacetic acid; butyl 2-[4-(5-trifluoromethyl-2-pyridyloxy)phenoxy]propionate (including esters and salts thereof); and ethyl 2-[4-(6-chloro-2-quinoxalinyloxy)phenoxy]propionate; (B) Diphenyl ether type herbicide such as 2,4-dichlorophenyl-4'-nitrophenyl ether; 2,4,6-trichlorophenyl 4'-nitrophenyl ether; 2,4-dichlorophenyl 4'-nitro-3'-methoxyphenyl ether; 2,4-dichlorophenyl 3'-methoxycarbonyl-4'-nitrophenyl ether; 2-chloro-4-trifluoromethylphenyl 3'-ethoxy-4'-nitrophenyl ether; and sodium 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoate; (C) Triazine type herbicide such as 2-chloro-4,6-bis-ethylamino-1,3,5-triazine; 2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine; and 2-methylthio-4,6-bis-ethylamino-1,3,5-triazine; (D) Urea type herbicide such as 3-(3,4-dichlorophenyl)-1,1-dimethylurea; 3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea; 3-(α,α,α-trifluoro-m-tolyl)-1,1-dimethylurea; 3-[4-(4-methylphenethyloxy)phenyl]-1-methoxy-1-methylurea; and 3-(5-t-butyl-3,4-thiadiazol-2-yl)-4-hydroxy-1-methyl-2- imidazolidone; (E) Carbamate type herbicide such as isopropyl N-(3-chlorophenyl)carbamate; methyl N-(3,4-dichlorophenyl)carbamate; and 4-chloro-2-butynyl N-(3-chlorophenyl)carbamate; (F) Thiolcarbamate type herbicide such as S-ethyl N,N-hexamethylenethiolcarbamate; S-(4-chlorobenzyl) N,N-diethylthiolcarbamate; and S-ethyl dipropylthiolcarbamate; (G) Anilide type herbicide such as 3,4-dichloropropionanilide; N-methoxymethyl-2',6'-diethyl-2-chloroacetanilide; 2-chloro-2',6'-diethyl-N-(butoxymethyl)acetanilide; 2-chloro-2',6'-diethyl-N-(propoxyethyl)acetanilide; and α-(2-naphthoxy)propionanilide; (H) Uracil type herbicide such as 5-bromo-3-sec-butyl-6-methyluracil; and 3-cyclohexyl-5,6-trimethyleneuracil; (I) Dipyridinium salt type herbicide such as 1,1'-dimethyl-4,4'-dipyridinium dichloride; and 1,1'-ethylene-2,2'-dipyridinium dibromide; (J) Phosphorus type herbicide such as N-(phosphonomethyl)glycine; O-ethyl-O-(2-nitro-5-methylphenyl)-N-sec-butylphosphoroamidothioate; O-methyl-O-(2-nitro-4-methylphenyl)-N-isopropylphos phoroamidothioate; S-(2-methyl-1,1-piperidylcarbonylmethyl)-O,O-di-n-propyl dithiophosphate; and (2-amino-4-methylphosphinobutyryl)alanylalanine monosodium salt; (K) Toluidine type herbicide such as α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine; and N-(cyclopropylmethyl)-α,α,α-trifluoro-2,6-dinitro-N-propyl-p-toluidine; (L) Other herbicides such as 5-t-butyl-3-(2,4-dichloro-5-isopropoxyphenyl)-1,3,4-oxadiazolin-2-one; 3-isopropyl-2,1,3-benzothiaziadinone-4,2,2-dioxide; 2(α-naphthoxy)-N,N-diethylpropionamide; 3-amino-2,5-dichlorobenzoic acid; 4-(2,4-dichlorobenzoyl)-1,3-dimethylpyrazol-5-yl-p-toluene sulfonate, 2-chloro-N-[(4-methoxy-6-methyl-1,3,5-triazine-2-yl)aminocarbonyl]benzenesulfonamide; methyl 2-[(4,6-dimethoxypyrimidin-2-yl)aminocarbonylaminosulfonylmethyl]benzoate; N-(1-methyl-1-phenylethyl)-2-bromo-3,3-dimethylbutanamide; 2-[1-(N-allyloxyamino)butylidene]-4-methoxycarbonyl-5,5-dimethylcyclohexane-1,3-dione sodium salt; and 2-[1-ethoxyimino)butyl]-5-(2-ethylthiopropyl)-3-hydroxy-2-cyclohexan-1-one; The foregoing herbicides are mentioned only as the examples, and they should not be construed to be limiting the scope of herbicides which can be utilized in combination with the compound of the present invention. The herbicide of the present invention may also be applied in combination with insecticides such as pyrethroid type insecticides and the like, fungicides, plant growth regulators, microbial agricultural chemicals and fertilizers. In a further aspect of the present invention, there is provided a method for the destruction of undesirable weeds, which comprises applying to said weeds, in an amount of from 0.4 to 100 g/10a in terms of the amount of an active ingredient, a herbicidal composition which comprises as an active ingredient a herbicidally effective amount of an N-substituted-phenylteraconimide compound represented by the formula wherein R and X are as defined above. The above-described method is useful in selectively and effectively controlling undesirable weeds among desirable crop plants. Further, the method is continuously useful through the whole period of growth of crop plants including broad-leaved crop plants such as soybean, cotton and the like and crop plants belonging to the family Gramineae such as rice, corn and wheat plants. In Application Examples which will be given later and in which the active compound is applied in the form of a herbicidal composition, the dosage of the composition is expressed using the unit "a.i. g/10a" which means "g/10a in terms of the amount of an active ingredient". The present invention will now be explained in more detail with reference to Synthesis Examples with respect to the synthesis of the compounds of the present invention, Preparation Examples with respect to the recipes for the herbicidal compositions and Application Examples with respect to effectiveness of the herbicidal compositions of the present invention. These Examples are not to be construed as limiting the scope of the present invention in any manner. SYNTHESIS EXAMPLE Example 1 Synthesis of N-(2-fluoro-4-chloro-5-hydroxyphenyl)teraconimide: Compound No. 69 11 g of teraconic acid anhydride and 13 g of 2-chloro-4-fluoro-5-aminophenol were dissolved in 250 ml of acetic acid and the solution was heated under reflux at about 130 ° to 140 °C for 5 hours. After completion of the reaction, the acetic acid was distilled off under reduced pressure to obtain a crude product. The thus obtained crude product was subjected to purification by the column chromatography using a mixture of toluene and acetone as the eluent, thereby to obtain 17 g of a yellow viscous liquid of N-(2-fluoro-4-chloro-5-hydroxyphenyl)teraconimide. Example 2 Synethesis of N-(2-fluoro-4-chloro-5-propargyloxyphenyl)teraconimide: Compound No. 71 1.5 g of a potassium salt of N-(2-fluoro-4-chloro-5-hydroxyphenyl)teraconimide and 0.6 g of propargyl bromide were dissolved in 20 ml of tetrahydrofuran. To the solution was added 0.1 g of 18-crown-6, followed by stirring at 40 ° to 50 °C for 3 hours. After completion of the reaction, the tetrahydrofuran was distilled off under reduced pressure to obtain a crude product. The thus obtained crude product was subjected to purification by the column chromatography using a mixture of toluene and acetone as the eluent, thereby to obtain 0.7 g of a light yellow crystalline substance of N-(2-fluoro-4-chloro-5-propargyloxyphenyl)teraconimide having a melting point of 134.7 ° to 135.5 °C. Example 3 Synthesis of N-(4-chloro-5-hydroxyphenyl)teraconimide: Compound No. 49 11 g of teraconic acid anhydride and 11 g of 2-chloro-5-aminophenol were dissolved in 250 ml of acetic acid and the solution was heated under reflux at about 130 ° to 140 °C for 5 hours. After completion of the reaction, the acetic acid was distilled off to obtain a crude product. The thus obtained crude product was subjected to purification by the column chromatography using a mixture of toluene and acetone as the eluent, thereby to obtain 14 g of a light yellow crystalline substance of N-(4-chloro-5-hydroxyphenyl)teraconimide having a melting point of 164.8 ° to 165.7 °C. Example 4 Synthesis of N-(4-chloro-5-propargyloxyphenyl)teraconimide: Compound No. 51 1.5 g of a potassium salt of N-(4-chloro-5-hydroxyphenyl)teraconimide and 0.6 g of propargyl bromide were dissolved in 20 ml of tetrahydrofuran. To the solution was added 0.1 g of 18-crown-6, followed by stirring at 40 ° to 50 °C for 3 hours. After completion of the reaction, the tetrahydrofuran was distilled off under reduced pressure to obtain a crude product. The thus obtained crude product was subjected to purification by the column chromatography using a mixture of toluene and acetone as the eluent, thereby to obtain 0.7 g of a light yellow crystalline substance of N-(4-chloro-5-propargyloxyphenyl)teraconimide having a melting point of 161.5 ° to 162.2 °C. Example 5 Synthesis of N-(2,4-dichloro-5-hydroxyphenyl)teraconimide: Compound No. 9 11 g of teraconic acid anhydride and 14 g of 2,4-dichloro-5-aminophenol were dissolved in 250 ml of acetic acid. The solution was heated under reflux at about 130 ° to 140 °C for 5 hours. After completion of the reaction, the acetic acid was distilled off under reduced pressure to obtain a crude product. The thus obtained crude product was subjected to purification by the column chromatography using a mixture of toluene and acetone as the eluent, thereby to obtain 13 g of a light yellow crystalline substance of N-(2,4-dichloro-5-hydroxyphenyl)teraconimide having a melting point of 157.0 ° to 157.3 °C. Example 6 Synthesis of N-(2,4-dichloro-5-propargyloxyphenyl)teraconimide: Compound No. 11 1.5 g of a potassium salt of N-(2,4-dichloro-5-hydroxyphenyl)teraconimide and 0.6 g of propargyl bromide were dissolved in 20 ml of tetrahydrofuran. To the solution was added 0.1 g of 18-crown-6, followed by stirring at 40 ° to 50 °C for 3 hours. After completion of the reaction, the tetrahydrofuran was distilled off under reduced pressure to obtain a crude product. The thus obtained crude product was subjected to purification by the column chromatography using a mixture of toluene and acetone as the eluent, thereby to obtain 0.8 g of a light yellow crystalline substance of N-(2,4-dichloro-5-propargyloxyphenyl)teraconimide having a melting point of 128.5 ° to 129.3 °C. Example 7 Synthesis of N-[5-[1-(sec-butylcarbamoyl)ethylamino]-4-chlorophenyl]teraconimide: Compound No. 87 5.3 g of N-(3-amino-4-chlorophenyl)teraconimide, 4.6 g of N-sec-butyl-α-bromopropionamide and 2 g of sodium bicarbonate were mixed and then heated at 160 °C for 3 hours to effect reaction. After completion of the reaction, the resultant mixture was cooled and dissolved in acetone, followed by filtration-removal of the insoluble substances. The acetone in the filtrate was distilled off to obtain a crude product. The thus obtained crude product was subjected to purification by the silica gel column chromatography using a mixture of toluene and acetone as the eluent, thereby to obtain 3.4 g of a yellow crystalline substance of N-[5-[1-(sec-butylcarbamoyl)ethylamino]-4-chlorophenyl]teraconimide having a melting point of 58.5 ° to 59.5 °C. Example 8 Various N-substituted-phenylteraconimide compounds of the present invention were synthesized from respective corresponding starting materials as indicated in Tables 1A to 1D in substantially the same manner as in Examples mentioned above. The physical properties and analytical data of these compounds are as shown in the Tables. In the columns of physical property in the Tables, the term "viscous liquid" means that the prepared compounds were viscous liquids at room temperature immediately after synthesis. The ¹H-NMR spectral data were obtained by using PMX-60 Si type analyzer (trade name of an ¹H-NMM analyzer produced by JEOL, Japan). Thin-layer chromatography (TLC) was effected using, as the silica gel plate, No. 5729 silica gel plate produced by Merck and Co., Inc., USA, and as the eluent, a 8:2 mixture of toluene and acetone. PREPARATION EXAMPLE Preparation Example 1 (wettable powder) 25 Parts by weight of the compound of the present invention, 5 parts by weight of Sorpol 5039 (trade name of a product of Toho Chemical Industry Company, Japan) and 70 parts by weight of talc are thoroughly pulverized and mixed to obtain wettable powder. Preparation Example 2 (emulsifiable concentrate) 5 Parts by weight of the compound of the present invention, 10 parts by weight of Sorpol 3005 X (a product of Toho Chemical Industry Company, Japan), 45 parts by weight of n-butanol and 40 parts by weight of xylene are thoroughly mixed to obtain emulsifiable concentrate. Preparation Example 3 (granule) 1 Part by weight of the compound of the present invention, 45 parts by weight of bentonite, 44 parts by weight of clay, 5 parts by weight of sodium lignosulfonate and 5 parts by weight of sodium dodecylbenzenesulfonate are thoroughly pulverized and mixed. To the mixture is added water, and the resultant is thoroughly kneaded. The kneaded mixture is then subjected to granulation, followed by drying, thereby to obtain granule. Preparation Example 4 (dust) 1 Part by weight of the compound of the present invention and 99 parts by weight of clay are thoroughly pulverized and mixed to obtain dust. APPLICATION EXAMPLE Application Example 1 Pots each having a surface area of 1/5000 a were packed with paddy field soil in a greenhouse. In each pot, rice seedlings of 3 leaf stage were transplanted at a depth of 2 to 3 cm from the surface soil. Seeds of barnyardgrass and monochoria, and seeds of broad-leaved annual weeds, toothcup and false pimpernel, were mixed with dry paddy field soil and incorporated into the surface soil. Further, as a perennial weed, seeds of "Hotarui" ( Scirpus juncoides ) were planted. Using the compounds listed in Table 2, emulsifiable concentrates having a predetermined concentration were prepared according to the method described in Preparation Example 2. Each of the thus prepared concentrates was dropwise applied by means of a pipette when the barnyardgrass grew up to 1.5 to 2.0 leaf stage. 21 Days after the application, phytotoxicity to rice plants and herbicidal effects on weeds were observed. The results obtained were shown in Table 2. The values indicated in Table 2 are based on the following criterion. 5 : Perfect inhibition 4 : 80 % inhibition 3 : 60 % inhibition 2 : 40 % inhibition 1 : 20 % inhibition 0 : No effect Application Example 2 Pots each having a surface area of 1/2500 a were packed with upland soil in a greenhouse. In each pot were planted seeds of soybeans Indian corn, crabgrass, livid amaranth and smartweed. The application was effected, by applying a composition in a dosage of 10 a.i. g/10a, 24 hours after the planting of the seeds. The herbicidal composition was prepared and applied as follows. Using the compounds listed in Table 3, emulsifiable concentrates having a predetermined concentration were prepared according to the method described in Preparation Example 2. Each of the thus prepared concentrates were diluted with 15 g of water per each are of the upland soil, and then applied by means of a glass sprayer. 14 Days after the application, the degree of the herbicidal effect on weeds was observed. 30 Days after the application, the degree of the phytotoxicity to crop plants was observed. The results obtained are shown in Table 3. The criteria for the values indicated in Table 3 are the same as those employed in Application Example 1. Compound No. Herbicidal Activity and Phytotoxicity Crabgrass Livid amaranth Smartweed Soybean Indian corn 1 5 5 4 0 0 6 5 5 5 0 0 10 5 5 5 0 0 11 5 5 5 0 0 34 5 5 5 0 0 45 5 5 4 0 0 46 5 5 5 0 0 48 5 5 5 0 0 50 5 5 5 0 0 51 5 5 5 0 0 65 5 5 5 0 0 66 5 5 5 0 0 67 5 5 5 0 0 70 5 5 5 0 0 71 5 5 5 0 0 87 5 5 5 0 0 106 5 5 5 0 0 107 5 5 5 0 0 110 5 5 5 0 0 111 5 5 5 0 0 118 5 5 5 0 0 Comparative Compound No. 1 4 3 3 0 0

Claims: An N-substituted-phenylteraconimide compound represented by the formula wherein X represents a hydrogen atom, a fluorine atom or a chlorine atom; and R represents -OR¹ or in which R¹ represents a hydrogen atom, a straight chain or branched alkyl group having up to 8 carbon atoms, a straight chain or branched alkenyl group having up to 8 carbon atoms, an alkynyl group having up to 8 carbon atoms, a cycloalkyl group having up to 8 carbon atoms wherein an oxygen atom, a sulfur atom or a carbonyl group may be substituted for a carbon atom, a straight chain or branched alkyl or alkenyl group having up to 8 carbon atoms and substituted with at least one substituent selected from the group consisting of a halogen atom, a cyano group, a hydroxyl group, an alkoxyl group having up to 8 carbon atoms, an alkylthio group having up to 8 carbon atoms, an epoxy group, an acyl group having up to 8 carbon atoms and an alkoxycarbonyl group having up to 8 carbon atoms, or a 1-methylbenzyl, phenethyl, p-chlorobenzyl, p-methylbenzyl, p-methoxybenzyl or cinnamyl group, R² represents a hydrogen atom or a straight chain or branched alkyl group having up to 8 carbon atoms, and R³ and R⁴ each independently represent a hydrogen atom, a straight chain or branched alkyl group having up to 8 carbon atoms, a straight chain or branched alkenyl group having up to 8 carbon atoms, an alkynyl group having up to 8 carbon atoms, an alkoxyl group having up to 8 carbon atoms, an alkoxyalkyl group having up to 8 carbon atoms, an alkoxycarbonylalkyl group having up to 8 carbon atoms, a cycloalkyl group having up to 8 carbon atoms, a hydroxyalkyl group having up to 8 carbon atoms, a cyanoalkyl group having up to 8 carbon atoms, an aralkyl group having up to 9 carbon atoms or an aryl group having up to 8 carbon atoms, or R³ and R⁴ are directly bonded with each other, thereby forming with the nitrogen atom bonded therewith a heterocyclic ring group having up to 7 carbon atoms, in the skeleton of which an oxygen atom is contained or not contained. A compound according to claim 1, wherein X represents a fluorine atom, and R¹ represents a straight chain or branched alkyl group having up to 8 carbon atoms, a straight chain or branched alkenyl group having up to 8 carbon atoms or an alkynyl group having up to 8 carbon atoms. A compound according to claim 1, wherein X represents a chlorine atom, and R¹ represents a straight chain or branched alkyl group having up to 8 carbon atoms, a straight chain or branched alkenyl group having up to 8 carbon atoms or an alkynyl group having up to 8 carbon atoms. A compound according to claim 1, wherein x represents a fluorine atom, R² represents a methyl group, and R³ and R⁴ are directly bonded with each other, thereby forming with the nitrogen atom bonded therewith a heterocyclic ring group, in the skeleton of which an oxygen atom is contained or not contained, or R³ represents a straight chain or branched alkyl group having up to 8 carbon atoms, a straight chain or branched alkenyl group having up to 8 carbon atoms, an alkynyl group having up to 8 carbon atoms, an alkoxyl group having up to 8 carbon atoms or a cycloalkyl group having up to 8 carbon atoms, and R⁴ represents a hydrogen atom, a straight chain or branched alkyl group having up to 8 carbon atoms, a straight chain or branched alkenyl group having up to 8 carbon atoms or an alkynyl group having up to 8 carbon atoms. A compound according to claim 1, wherein x represents a hydrogen atom, R² represents a methyl group, and R³ and R⁴ are directly bonded with each other, thereby forming with the nitrogen atom bonded therewith a heterocyclic ring group, in the skeleton of which an oxygen atom is contained or not contained, or R³ represents a straight chain or branched alkyl group having up to 8 carbon atoms, a straight chain or branched alkenyl group having up to 8 carbon atoms, an alkynyl group having up to 8 carbon atoms, an alkoxyl group having up to 8 carbon atoms or a cycloalkyl group having up to 8 carbon atoms, and R⁴ represents a hydrogen atom, a straight chain or branched alkyl group having up to 8 carbon atoms, a straight chain or branched alkenyl group having up to 8 carbon atoms or an alkynyl group having up to 8 carbon atoms. A compound according to claim 1, wherein X represents a fluorine atom, and R¹ represents an alkoxyalkyl group having up to 8 carbon atoms. A compound according to claim 1 selected from the group consisting of: N-(2,4-dichloro-5-propargyloxyphenyl)teraconimide, N-(2,4-dichloro-5-allyloxyphenyl)teraconimide, N-(2,4-dichloro-5-isopropoxyphenyl)teraconimide, N-(2,4-dichloro-5-methoxyphenyl)teraconimide, N-[2,4-dichloro-5-(1-methylallyloxy)phenyl]teraconimide, N-(2-fluoro-4-chloro-5-propargyloxyphenyl)teraconimide, N-(2-fluoro-4-chloro-5-allyloxyphenyl)teraconimide, N-(2-fluoro-4-chloro-5-isopropoxyphenyl)teraconimide, N-(2-fluoro-4-chloro-5-methoxyphenyl)teraconimide, N-(2-fluoro-4-chloro-5-methoxymethoxyphenyl)teraconimide, N-[2-fluoro-4-chloro-5-(1-methylallyloxy)phenyl]teraconimide, N-[5-[1-(N-methoxy-N-methylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(N,N-diethylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(N-propoxycarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, and N-[5-[1-(N-propargylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide. A herbicidal composition which comprises as an active ingredient a herbicidally effective amount of an N-substituted-phenylteraconimide compound represented by the formula wherein X represents a hydrogen atom, a fluorine atom or a chlorine atom; and R represents -OR¹ or in which R¹ represents a hydrogen atom, a straight chain or branched alkyl group having up to 8 carbon atoms, a straight chain or branched alkenyl group having up to 8 carbon atoms, an alkynyl group having up to 8 carbon atoms, a cycloalkyl group having up to 8 carbon atoms wherein an oxygen atom, a sulfur atom or a carbonyl group may be substituted for a carbon atom, a straight chain or branched alkyl or alkenyl group having up to 8 carbon atoms and substituted with at least one substituent selected from the group consisting of a halogen atom, a cyano group, a hydroxyl group, an alkoxyl group having up to 8 carbon atoms, an alkylthio group having up to 8 carbon atoms, an epoxy group, an acyl group having up to 8 carbon atoms and an alkoxycarbonyl group having up to 8 carbon atoms, or a 1-methylbenzyl, phenethyl, p-chlorobenzyl, p-methylbenzyl, p-methoxybenzyl, or cinnamyl group, R² represents a hydrogen atom or a straight chain or branched alkyl group having up to 8 carbon atoms, and R³ and R⁴ each independently represent a hydrogen atom, a straight chain or branched alkyl group having up to 8 carbon atoms, a straight chain or branched alkenyl group having up to 8 carbon atoms, an alkynyl group having up to 8 carbon atoms, an alkoxyl group having up to 8 carbon atoms, an alkoxyalkyl group having up to 8 carbon atoms, an alkoxycarbonylalkyl group having up to 8 carbon atoms, a cycloalkyl group having up to 8 carbon atoms, a hydroxyalkyl group having up to 8 carbon atoms, a cyanoalkyl group having up to 8 carbon atoms, an aralkyl group having up to 9 carbon atoms or an aryl group having up to 8 carbon atoms, or R³ and R⁴ are directly bonded with each other, thereby forming with the nitrogen atom bonded therewith a heterocyclic ring group having up to 7 carbon atoms, in the skeleton of which an oxygen atom is contained or not contained. A herbicidal composition according to claim 8, wherein X represents a fluorine atom, and R¹ represents a straight chain or branched alkyl group having up to 8 carbon atoms, a straight chain or branched alkenyl group having up to 8 carbon atoms or an alkynyl group having up to 8 carbon atoms. A herbicidal composition according to claim 8, wherein X represents a chlorine atom, and R¹ represents a straight chain or branched alkyl group having up to 8 carbon atoms, a straight chain or branched alkenyl group having up to 8 carbon atoms or an alkynyl group having up to 8 carbon atoms. A herbicidal composition according to claim 8, wherein X represents a fluorine atom, R² represents a methyl group, and R³ and R⁴ are directly bonded with each other, thereby forming with the nitrogen atom bonded therewith a heterocyclic ring group, in the skeleton of which an oxygen atom is contained or not contained, or R³ represents a straight chain or branched alkyl group having up to 8 carbon atoms, a straight chain or branched an alkenyl group having up to 8 carbon atoms, an alkynyl group having up to 8 carbon atoms, an alkoxyl group having up to 8 carbon atoms or a cycloalkyl group having up to 8 carbon atoms, and R⁴ represents a hydrogen atom, a straight chain or branched alkyl group having up to 8 carbon atoms, a straight chain or branched alkenyl group having up to 8 carbon atoms or an alkynyl group having up to 8 carbon atoms. A herbicidal composition according to claim 8, wherein x represents a hydrogen atom, R² represents a methyl group, and R³ and R⁴ are directly bonded with each other, thereby forming with the nitrogen atom bonded therewith a heterocyclic ring group, in the skeleton of which an oxygen atom is contained or not contained, or R³ represents a straight chain or branched alkyl group having up to 8 carbon atoms, a straight chain or branched alkenyl group having up to 8 carbon atoms, an alkynyl group having up to 8 carbon atoms, an alkoxyl group having up to 8 carbon atoms or a cycloalkyl group having up to 8 carbon atoms, and R⁴ represents a hydrogen atom, a straight chain or branched alkyl group having up to 8 carbon atoms, a straight chain or branched alkenyl group having up to 8 carbon atoms or an alkynyl group having up to 8 carbon atoms. A herbicidal composition according to claim 8, wherein X represents a fluorine atom, and R¹ represents an alkoxyalkyl group having up to 8 carbon atoms. A herbicidal composition according to claim 8, wherein the active ingredient is at least one member selected from the group consisting of: N-(2,4-dichloro-5-propargyloxyphenyl)teraconimide, N-(2,4-dichloro-5-allyloxyphenyl)teraconimide, N-(2,4-dichloro-5-isopropoxyphenyl)teraconimide, N-(2,4-dichloro-5-methoxyphenyl)teraconimide, N-[2,4-dichloro-5-(1-methylallyloxy)phenyl]teraconimide, N-(2-fluoro-4-chloro-5-propargyloxyphenyl)teraconimide, N-(2-fluoro-4-chloro-5-allyloxyphenyl)teraconimide, N-(2-fluoro-4-chloro-5-isopropoxyphenyl)teraconimide, N-(2-fluoro-4-chloro-5-methoxyphenyl)teraconimide, N-(2-fluoro-4-chloro-5-methoxymethoxyphenyl)teraconimide, N-[2-fluoro-4-chloro-5-(1-methylallyloxy)phenyl]teraconimide, N-[5-[1-(N-methoxy-N-methylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(N,N-diethylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(N-propoxycarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, and N-[5-[1-(N-propargylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide. A method for the destruction of undesirable weeds, which comprises applying to said weeds, in an amount of from 0.4 to 100 g/10a in terms of the amount of an active ingredient, a herbicidal composition which comprises as an active ingredient a herbicidally effective amount of an N-substituted-phenylteraconimide compound represented by the formula wherein X represents a hydrogen atom, a fluorine atom or a chlorine atom; and R represents -OR¹ or in which R¹ represents a hydrogen atom, a straight chain or branched alkyl group having up to 8 carbon atoms, a straight chain or branched alkenyl group having up to 8 carbon atoms, an alkynyl group having up to 8 carbon atoms, a cycloalkyl group having up to 8 carbon atoms wherein an oxygen atom, a sulfur atom or a carbonyl group may be substituted for a carbon atom, a straight chain or branched alkyl or alkenyl group having up to 8 carbon atoms and substituted with at least one substituent selected from the group consisting of a halogen atom, a cyano group, a hydroxyl group, an alkoxyl group having up to 8 carbon atoms, an alkylthio group having up to 8 carbon atoms, an epoxy group, an acyl group having up to 8 carbon atoms and an alkoxycarbonyl group having up to 8 carbon atoms, or a 1-methylbenzyl, phenethyl, p-chlorobenzyl, p-methylbenzyl, p-methoxybenzyl, or cinnamyl group, R² represents a hydrogen atom or a straight chain or branched alkyl group having up to 8 carbon atoms, and R³ and R⁴ each independently represent a hydrogen atom, a straight chain or branched alkyl group having up to 8 carbon atoms, a straight chain or branched alkenyl group having up to 8 carbon atoms, an alkynyl group having up to 8 carbon atoms, an alkoxyl group having up to 8 carbon atoms, an alkoxyalkyl group having up to 8 carbon atoms, an alkoxycarbonylalkyl group having up to 8 carbon atoms, a cycloalkyl group having up to 8 carbon atoms, a hydroxyalkyl group having up to 8 carbon atoms, a cyanoalkyl group having up to 8 carbon atoms, an aralkyl group having up to 9 carbon atoms or an aryl group having up to 8 carbon atoms, or R³ and R⁴ are directly bonded with each other, thereby forming with the nitrogen atom bonded therewith a heterocyclic ring group having up to 7 carbon atoms, in the skeleton of which an oxygen atom is contained or not contained. A method according to claim 15, wherein X represents a fluorine atom, and R¹ represents a straight chain or branched alkyl group having up to 8 carbon atoms, a straight chain or branched alkenyl group having up to 8 carbon atoms or an alkynyl group having up to 8 carbon atoms. A method according to claim 15, wherein X represents a chlorine atom, and R¹ represents a straight chain or branched alkyl group having up to 8 carbon atoms, a straight chain or branched alkenyl group having up to 8 carbon atoms or an alkynyl group having up to 8 carbon atoms. A method according to claim 15, wherein x represents a fluorine atom, R² represents a methyl group, and R³ and R⁴ are directly bonded with each other, thereby forming with the nitrogen atom bonded therewith a heterocyclic ring group, in the skeleton of which an oxygen atom is contained or not contained, or R³ represents a straight chain or branched alkyl group having up to 8 carbon atoms, a straight chain or branched alkenyl group having up to 8 carbon atoms, an alkynyl group having up to 8 carbon atoms, an alkoxyl group having up to 8 carbon atoms or a cycloalkyl group having up to a carbon atoms, and R⁴ represents a hydrogen atom, a straight chain or branched alkyl group having up to 8 carbon atoms, a straight chain or branched alkenyl group having up to 8 carbon atoms or an alkynyl group having up to 8 carbon atoms. A method according to claim 15, wherein x represents a hydrogen atom, R² represents a methyl group, and R³ and R⁴ are directly bonded with each other, thereby forming with the nitrogen atom bonded therewith a heterocyclic ring group, in the skeleton of which an oxygen atom is contained or not contained, or R³ represents a straight chain or branched alkyl group having up to 8 carbon atoms, a straight chain or branched alkenyl group having up to 8 carbon atoms, an alkynyl group having up to 8 carbon atoms, an alkoxyl group having up to 8 carbon atoms or a cycloalkyl group having up to 8 carbon atoms, and R⁴ represents a hydrogen atom, a straight chain or branched alkyl group having up to 8 carbon atoms, a straight chain or branched alkenyl group having up to 8 carbon atoms or an alkynyl group having up to 8 carbon atoms. A method according to claim 15, wherein X represents a fluorine atom, and R¹ represents an alkoxyalkyl group having up to 8 carbon atoms. A method according to claim 15, wherein the compound is at least one member selected from the group consisting of: N-(2,4-dichloro-5-propargyloxyphenyl)teraconimide, N-(2,4-dichloro-5-allyloxyphenyl)teraconimide, N-(2,4-dichloro-5-isopropoxyphenyl)teraconimide, N-(2,4-dichloro-5-methoxyphenyl)teraconimide, N-[2,4-dichloro-5-(1-methylallyloxy)phenyl]teraconimide, N-(2-fluoro-4-chloro-5-propargyloxyphenyl)teraconimide, N-(2-fluoro-4-chloro-5-allyloxyphenyl)teraconimide, N-(2-fluoro-4-chloro-5-isopropoxyphenyl)teraconimide, N-(2-fluoro-4-chloro-5-methoxyphenyl)teraconimide, N-(2-fluoro-4-chloro-5-methoxymethoxyphenyl)teraconimide, N-[2-fluoro-4-chloro-5-(1-methylallyloxy)phenyl]teraconimide, N-[5-[1-(N-methoxy-N-methylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(N,N-diethylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, N-[5-[1-(N-propoxycarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide, and N-[5-[1-(N-propargylcarbamoyl)ethylamino]-2-fluoro-4-chlorophenyl]teraconimide.

Inventors: KOUJI, HIROYUKI, MISUMI, TERUYUKI
Applicants: ASAHI KASEI KOGYO KABUSHIKI KAISHA
Application year: 1986
Main classification: C07D207
IPC codes: A01N43, C07D207