Uracil derivatives and herbicides containing the same as active ingredient

Abstract: Disclosed herein is uracil derivatives having a haloalkyl group at the 5-position and a phenyl group at the 2-position which has a specific substituent, which are represented by the formula (I) and showing penetrative translocation activity and a very high herbicidal activity, in which as compared with the conventional herbicidal compounds, the said uracil derivatives can be applied for either soil treatment or foliage treatment, thereby producing a quick and high herbicidal effect even at a very low dosage against a large variety of weeds including perennial weeds, and have the property to residual effect for an appropriate period of time.

Description: The present invention relates to novel uracil derivatives and herbicides having an selectivity and containing the uracil derivatives as active ingredients. A large variety of herbicides have been prepared and practically used for protecting important crop plants such as rice, soybean, wheat, corn, cotton and beet from weeds and for enhancing productivity of these crop plants. The herbicides may be roughly classified into the following three types according to the locality of application: 1 ○ herbicides for upland cropping, 2 ○ herbicides for paddy field and 3 ○ herbicides for non-arable land. Each kind of herbicides can be further classified into subclasses such as soil incorporation treatment type, pre-emergence treatment type and post-emergency treatment type (foliage treatment) according to the method of application. With increase of global population in recent years, there is no denying the fact that productivity of principal crop plants gives a serious influence to food economy of each country, and thus enhancement of productivity of principal crop plants is now a matter of paramount importance. In fact, for the people engaged in farming, it is still more necessary to develop herbicides which are capable of economical and efficient killing or controlling of growth of weeds which do harm to cultivation of crop plants. As such herbicides, there are demanded the ones which can meet the following requirements: (1) Herbicidal effect is high with small amount of application. (It is necessary, especially from the viewpoint of environmental protection, to kill the weeds by application of as small as amount of herbicide as possible.) (2) Residual effect is appropriate. (Recently, the problem is pointed out that the chemicals retaining their effect in soil for a long time could give damage to the next crop plants. It is thus important that the chemicals keep an appropriate residual effect after application). (3) Weeds are killed quickly after application. (It is made possible to perform seeding and transplantation of the next crop plant in a short time after chemicals treatment.) (4) The number of times of herbicide treatment (application) required is small. (It is of much account for the farmers that the number of times of weed-controling work be minimized.) (5) Weeds killed or controlled by one of herbicide is of wide range. (It is desirable that different weeds such as broad-leaved weeds, graminaceous weeds and perennial weeds can be killed or controlled by application of one of herbicide.) (6) The application method is diversified. (The herbicidal effect is intensified when it can be applied in various ways, such as soil treatment or foliage treatment). (7) No damage to crop plants is given. (In a cultivated field where both crop plants and weeds co-exist, it is desirable that weeds alone are killed selectively by a herbicide.) Nevertheless, there is yet available no herbicide which can meet all of the above requirements. It is known that certain compounds of uracil derivatives have a herbicidal activity. For instance, in the Pesticide Manual, 8th Ed., p. 89 (published by The British Crop Protection Council, 1987), Bromacil as one the herbicides having uracil skeleton is disclosed. There are also known the following hetero-ring derivatives which can serve as active ingredient for herbicides: (1) 3-Aryluracil-alkyl, alkenyl and alkinylenol ethers represented by the following general formula: wherein R 1 represents C 1-8 alkyl, C 2-6 alkenyl, C 2-6 alkynyl, C 2-8 alkoxyalkyl or R 2 represents halogen or cyano, R 3 represents hydrogen or halogen, R 4 represents hydrogen, fluorine or C 1-4 alkyl, R 5 represents C 1-4 alkyl or C 1-4 haloalkyl, or R 4 and R 5 may combine to represent tri- or tetra-methylene (in which R 6 and R 7 represent independently C 1-4 alkyl, and m is 1 or 2), and X is O, O-C(O), O-C(O)-O or C(O)-O (Japanese Patent Application Laid-Open (Kokai) No. 63-107967). (2) Compounds represented by the following general formula: wherein R 1 represents hydrogen, C 1-4 alkyl, C 1-4 haloalkyl, formyl or C 2-6 alkanonyl, R 2 represents ether or a residue containing (thio)carbonyloxy or sulfonyloxy, the residue being directly linked to benzene nucleus A through oxygen atom, R 3 represents halogen or cyano, R 4 represents hydrogen or halogen, R 5 represents hydrogen, halogen or C 1-4 alkyl, and R 6 represents C 1-4 alkyl or C 1-4 haloalkyl, or R 5 and R 6 may be combined together to represent tri- or tetrametylene, and salts of the compounds of the said formula wherein R 1 is hydrogen (Japanese Patent Application Laid-Open (Kokai) No. 63-41466 corresponding to EP-A-255,047). (3) Benzothiazolone derivatives represented by the general formula: wherein R represents hydrogen, lower alkyl, lower alkenyl, lower alkynyl, lower haloalkyl, lower haloalkenyl, lower haloalkynyl, lower alkoxy-lower alkyl, lower alkoxy-lower alkoxy-lower alkyl, cinnamyl or lower cyanoalkyl (Japanese Patent Application Laid-Open (Kokai) No. 62-155276). (4) Condensed hetero-ring derivatives represented by the general formula: wherein X represents oxygen atom or sulfur atom, and Z represents in which G represents hydrogen atom or halogen atom, A represents halogen atom or NO 2 , E represents hydrogen atom, halogen atom, C≡N, NO 2 , NH 2 , OH, SH, OR 1 [wherein R 1 represents C 1-5 alkyl, C 3-6 cycloalkyl, C 3-6 cycloalkyl-(C 1-2 ) alkyl, C 2-4 alkenyl, C 3-4 alkynyl, (in which Q a and Q b represent independently oxygen atom or sulfur atom, R 1a represents hydrogen atom or C 1-3 alkyl, and R 1b represents hydrogen atom, C 1-5 alkyl, C 2-5 alkenyl, C 3-5 alkynyl, C 2-3 haloalkyl, C 1-2 alkoxy-(C 1-2 ) alkyl, C 3-4 cycloalkyl-(C 1-2 ) alkyl, C 3-6 cycloalkyl, CH 2 CO 2 -(C 1-3 alkyl), or CH(CH 3 )-CO 2 -(C 1-2 alkyl), or R 1a and R 1b are combined to form a 4- to 6-membered ring lactone constituted by methylene chain), (in which R 1a and Q a are the same meaning as defined above, and R 1c and R 1d represent independently hydrogen atom, C 1-5 alkyl, C 2-5 alkenyl, C 3-5 alkynyl, C 2-5 haloalkyl, C 3-6 cycloalkyl or C 3-6 cycloalkyl-(C 1-2 ) alkyl, or R 1d and R 1c are combined to form a 5- to 7-membered ring constituted by methylene chain), CH2C≡N, tetrahydropyranyl, tetrahydrothiopyranyl, CH 2 COR 1e , (in which R 1e represents C 1-3 alkyl, R 1f represents hydrogen atom, C 1-3 alkyl, CH 2 CO 2 -(C 1-3 ) alkyl or COCH 3 ), or C 1-2 alkoxy-(C 1-2 ) alkyl], SR 3 (in which R 3 is the same meaning as R 1 described above), CO 2 R 5 (in which R 5 represents hydrogen atom, C 1-5 alkyl, C 3-6 cycloalkyl or C 3-6 cycloalkyl-(C 1-2 ) alkyl), NHR 6 (in which R 6 represents C 1-5 alkyl, C 3-6 cycloalkyl, C 3-6 cycloalkyl-(C 1-2 ) alkyl, C 2-4 alkenyl or C 3-4 alkynyl), or CH=NOR 7 (in which R 7 is hydrogen atom, C 1-5 alkyl, C 3-6 cycloalkyl, C 3-6 cycloalkyl-(C 1-2 ) alkyl, C 2-4 alkenyl or C 3-4 alkynyl), L represents hydrogen atom or halogen atom, Y represents oxygen atom or sulfur atom, n is 0 or 1, and J represents hydrogen atom, halogen atom, C 1-5 alkyl, C 3-6 cycloalkyl, C 3-6 cycloalkyl-(C 1-2 ) alkyl, C 2-4 alkenyl, C 3-4 alkynyl, C 1-5 haloalkyl, C 3-4 haloalkenyl, C 3-4 haloalkynyl, C 1-2 alkoxy-(C 1-2 ) alkyl, CH 2 C≡N, CH 2 CO 2 R 8 (in which R 8 is hydrogen atom, C 1-5 alkyl, C 3-6 cycloalkyl or C 3-6 cycloalkyl-(C 1-2 ) alkyl), or CH 2 CH 2 CO 2 R 9 (in which R 9 is hydrogen atom, C 1-5 alkyl, C 3-6 cycloalkyl or C 3-6 cycloalkyl-(C 1-2 ) alkyl) (Japanese Patent Application Laid-Open (Kokai) No. 1-250388). (5) Compounds represented by the following formula: wherein R 1 represents hydrogen, C 1-4 alkyl, C 2-4 alkenyl, C 2-4 alkynyl, C 2-6 alkoxyalkyl, formyl, C 2-6 alkanoyl or C 2-6 alkoxycarbonyl; R 2 represents hydrogen, C 1-6 alkyl, C 2-4 alkenyl, C 2-4 alkynyl or C 2-6 alkoxyalkyl; R 3 represents halogen or nitro; R 4 represents hydrogen or halogen; R 5 represents hydrogen, halogen, C 1-4 alkyl, chloromethyl, bromomethyl, hydroxymethyl, (C 1-5 alkoxy)methyl, (C 1-5 alkylthio)methyl, cyano, nitro or thiocyanato; R 6 represents hydrogen, C 1-4 alkyl or C 1-4 fluoroalkyl, or R 5 and R 6 are combined to represent tri- or tetramethylene, in which one of the said methylene groups may be substituted with oxygen or sulfur, or these groups may be substituted with C 1-3 alkyl; and X represents oxygen or sulfur, in which (i) when R 5 is fluorine, R 6 is C 1-4 alkyl or C 1-4 fluoroalkyl, and (ii) when R 5 is cyano, R 6 is hydrogen or C 1-4 alkyl, and X is oxygen, and salts of the compounds of the said formula wherein R 1 and/or R 2 represent(s) hydrogen (Japanese Patent Application Laid-Open (Kokai) No. 61-221178). (6) Tetrahydrophthalimide derivatives represented by the following formula: wherein R 1 represents C 1-5 alkyl, C 3-5 alkenyl, C 3-5 alkynyl or C 1-3 alkoxymethyl, X is hydrogen, fluorine or chlorine, and A represents (in which R 2 represents hydrogen or methyl, R 3 represents hydrogen or methyl, and nitrogen atom is bonded to benzene ring (Japanese Patent Application Laid-Open (Kokai) No. 61-85385). (7) Tetrahydrophthalimide derivatives represented by the following formula: wherein R 1 represents alkyl, alkenyl, alkynyl, alkoxyalkyl or alkoxyalkoxyalkyl, and R 2 represents hydrogen or methyl (Japanese Patent Application Laid-Open (Kokai) No. 61-30586). (8) Tetrahydrophthalimide derivatives represented by the following formula: wherein R 1 represents alkyl, alkenyl, alkynyl, alkoxyalkyl or alkoxyalkoxyalkyl, and R 2 represents hydrogen or methyl (Japanese Patent Application Laid-Open (Kokai) No. 61-76486). (9) Tetrahydrophthalimide derivatives represented by the following formula: wherein R represents C 1-5 alkyl, C 3-5 alkenyl, C 3-5 alkynyl or C 1-3 alkoxymethyl, and X represents hydrogen or fluorine (Japanese Patent Application Laid-Open (Kokai) No. 61-43188). (10) Herbicidal compounds having the general formula: wherein X is hydrogen or hydroxy, R 1 is hydrogen or halo and R 2 is alkyl, cycloalkyl, phenyl, alkenyl, and substituted derivatives of the above (U.S. Patent No. 3,981,715). (11) Herbicidal compounds having the general formula: wherein X is hydrogen or hydroxy, R 1 is hydrogen or halo and R 2 is alkyl, cycloalkyl, phenyl, alkenyl, and substituted derivatives of the above (U.S. Patent No. 3,869,457). (12) Compounds of formula (I): wherein R 1 represents hydrogen, C 1-4 alkyl, C 3-4 alkenyl, C 3-4 alkynyl or C 1-4 haloalkyl, R 2 represents or, when R 1 represents haloalkyl, hydrogen, C 1-8 alkyl, C 2-8 alkenyl, C 2-8 alkynyl or C 2-8 alkoxyalkyl, R 3 represents halogen or cyano, R 4 represents hydrogen or halogen and R 5 represents hydrogen, fluorine or C 1-4 haloalkyl, as well as their enol ethers and salts (WO 88/10254). (13) Compounds of formula: wherein R is hydrogen or various substituents, Y is hydrogen, fluorine or chlorine, X is a divalent group which completes a 5- or 6-membered ring and Z is a heterocyclic group (EP-A-311,135). Keen request is heard for the presentation of a herbicide which can meet the above-mentioned requirements (1) - (7), namely a herbicide which shows selectivity in potency, with no fear of giving any damage to crop plants (crop injury), exhibits excellent herbicidal effect at low dosage against a vide variety of weeds, and is also capable of exhibiting desired effect in both soil treatment and foliage treatment. As a result of the present inventors' extensive studies, it has been found that the uracil derivatives having a haloalkyl group at the 5-position and a phenyl group at the 2-position which has a specific substituent, which are represented by the following formula (I) have penetrative translocation activity and a very high herbicidal activity, and as compared with the conventional herbicidal compounds, the said uracil derivatives can be applied for either soil treatment or foliage treatment, thereby producing a quick and high herbicidal effect even at a very low dosage against a large variety of weeds including perennial weeds, and have the property to residual effect for an appropriate period of time. The present invention was attained on the basis of the said finding. The present invention provides a uracil derivative of formula (I): wherein R 1 represents hydrogen, C 1-3 alkyl, hydroxymethyl or C 1-3 haloalkyl, R 2 represents C 1-6 haloalkyl, R 3 represents hydrogen, C 1-6 alkyl, C 1-6 haloalkyl, hydroxymethyl, halogen or nitro, R 4 represents hydrogen or halogen, R 5 represents halogen, nitro or cyano, R 6 represents [wherein D 21 represents hydrogen, C 1-3 alkyl, C 1-3 alkoxyl or C 1-3 alkoxy-C 1-2 alkyl, and D 22 represents hydrogen, C 1-4 alkyl, C 3-6 cycloalkyl, C 2-3 haloalkyl, phenyl or benzyl]; [wherein D 21 and D 22 are as defined above, and D 23 represents hydrogen or C 1-3 alkyl]; [wherein D 25 represents hydrogen, sodium, C 1-4 alkyl, C 2-5 alkenyl, C 3-5 alkynyl, C 2-5 acyl, C 1-4 alkylsulfonyl or C 1-3 alkoxy-C 1-2 alkyl, and D 26 represents C 1-4 alkyl or C 1-3 haloalkyl]; and X represents oxygen or sulfur. The present invention also provides a herbicidal composition comprising a uracil derivative as defined above and a herbicidally acceptable carrier or diluent. The present invention additionally provides a method for controlling the growth of weeds at a locus, for example at a locus which contains wheat, which comprises applying thereto a uracil derivative as defined above. The present invention furthermore provides a process for producing a uracil derivative as defined above which comprises: (1) reacting phenyl iso(thio)cyanate of formula (VI): in which R 4 , R 5 , R 6 and X are as defined above, with a β-aminoacrylic ester of formula (V): in which R 2 and R 3 are as defined above and G 1 represents C 1-4 alkyl or phenyl, to form a compound of formula (I'): and, if desired, the compound of formula (I') is reacted with an alkylating agent to form a compound of formula (I) as defined above in which R 1 represents C 1-3 alkyl, hydroxymethyl or C 1-3 haloalkyl; (2) reacting an N-phenyl carbonate of formula (VII): in which R 4 , R 5 , R 6 and X are as defined above and G 2 represents C 1-4 alkyl or phenyl, with a β-aminoacrylic ester of formula (V) as defined above to form a compound of formula (I') as defined above, and, if desired, the compound of formula (I') is reacted with an alkylating agent to form a compound of formula (I) as defined above in which R 1 represents C 1-3 alkyl, hydroxymethyl or C 1-3 haloalkyl; (3) reacting phenyl iso(thio)cyanate of formula (VI) as defined above with an N-substituted-β-aminoacrylic ester of formula (VIII): in which G 1 is as defined above, R 2 and R 3 are as defined above and R 1 represents C 1-3 alkyl, hydroxymethyl or C 1-3 haloalkyl, to form a compound of formula (I) as defined above in which R 1 is as defined above; or (4) reacting an N-phenyl carbamate of formula (VII) as defined above with an N-substituted-β-aminoacrylic ester of formula (VIII) as defined above to form a compound of formula (I) as defined above in which R 1 represents C 1-3 alkyl, hydroxymethyl or C 1-3 haloalkyl. Among the uracil derivatives of formula (I), those of the formula (IV) are preferred: wherein R 1 represents hydrogen, C 1-3 alkyl or C 1-3 haloalkyl, R 2 represents C 1-6 haloalkyl, R 3 represents hydrogen, C 1-6 alkyl, C 1-6 haloalkyl, hydroxymethyl, halogen or nitro, R 4 represents hydrogen or halogen, R 5 represents halogen, nitro or cyano, D 1 represents [wherein D 21 represents hydrogen, C 1-3 alkyl, C 1-3 alkoxyl or C 1-3 alkoxy-C 1-2 alkyl, and D 22 represents hydrogen, C 1-4 alkyl, C 3-6 cycloalkyl, C 2-3 haloalkyl, phenyl or benzyl], [wherein D 21 and D 22 are as defined above, and D 23 represents hydrogen or C 1-3 alkyl], or [wherein D 25 represents hydrogen, sodium, C 1-4 alkyl, C 2-5 alkenyl, C 3-5 alkynyl, C 2-5 acyl, C 1-4 alkylsulfonyl or C 1-3 alkoxy-C 1-2 alkyl, and D 26 represents C 1-4 alkyl or C 1-3 haloalkyl], and X represents oxygen or sulfur. Among the compounds of formula (IV) the following are more preferable: wherein R 1 represents hydrogen or C 1-3 alkyl, R 2 represents C 1-4 haloalkyl, R 4 represents hydrogen or halogen, R 5 represents chlorine or nitro, and D 1 represents [wherein D 21 represents hydrogen, methyl, methoxy or methoxymethyl, and D 22 represents hydrogen, C 1-4 alkyl, C 3-6 cycloalkyl or benzyl], [wherein D 21 and D 22 are the same meaning as defined above, and D 23 is hydrogen or methyl], [wherein D 25 represents hydrogen, C 1-4 alkyl, C 2-5 alkenyl, C 3-5 alkynyl, or C 1-4 alkylsulfonyl, and D 26 represents C 1-4 alkyl]. Further preferred compounds are of formula: wherein R 2 represents halomethyl, R 4 represents halogen, R 5 represents halogen, and D 26 represents C 1-4 alkyl or halomethyl; and wherein D 26 represents methyl or ethyl. The uracil derivatives of the present invention can be synthesized according to the following reaction schemes: (1) In Scheme 1, phenyl iso(thio)cyanate (VI) is reacted with β-aminoacrylic ester (V) in which G 1 is C 1-4 alkyl or phenyl to form an uracil derivative (I') at the first stage, and after isolating said derivative (I') or without isolation thereof, the 1-position of the uracil ring thereof is alkylated to produce an uracil derivative of the formula (I) at the second stage. Reaction in the first stage Usually phenyl iso(thio)cyanate (VI) is used in an amount of 0.5 to 1.5 equivalents, preferably 0.9 to 1.1 equivalents to β-aminoacrylic ester (V). The reaction can proceed without solvent, but usually a solvent is used to accelerate the reaction. As the solvents usable for said purpose in the reaction, aliphatic hydrocarbons such as hexane, heptane, ligroine and petroleum ether; aromatic hydrocarbons such as benzene, toluene, xylene and chlorobenzene; halogenated hydrocarbons such as chloroform and methylene chloride; ethers such as diethyl ether, dioxane and tetrahydrofuran; ketones such as acetone and methyl ethyl ketone; nitriles such as acetonitrile and isobutyronitrile; tertiary amines such as pyridine and N,N-diethylaniline; acid amides such as formamide, N,N-dimethylformamide and N-methylpyrrolidone; sulfur-containing compounds such as dimethyl sulfoxide and sulfolane; water; and mixtures thereof may be exemplified. Among them, the aliphatic hydrocarbons, the acid amides, the sulfur-containing compounds and mixtures thereof are preferred. The reaction can proceed without base, but usually a base is used in an amount of 0.5 to 10 equivalents, preferably 1.0 to 2.0 equivalents to β-aminoacrylic ester (V). As base, there can be used, for instance, organic bases containing nitrogen such as pyridine, triethylamine and 1,4-diazabicyclo-2,2,2-octane; inorganic bases such as sodium hydride, potassium hydride, sodium hydroxide, potassium hydroxide, sodium carbonate and potassium carbonate; and metal alcoholates such as sodium methoxide, sodium ethoxide and potassium-tert-butoxide. Among them, sodium hydride, sodium hydroxide and potassium hydroxide are preferred. Reaction temperature is usually from -40 to 200°C, preferably from room temperature to reflux temperature of the reaction mixture. Reaction time is usually 10 minutes to 72 hours, preferably 30 minutes to 24 hours. After the reaction is completed, the derivative (I') can be isolated by making the reaction product acidic with a mineral acid such as hydrochloric acid or an organic acid such as acetic acid, trifluoroacetic acid, p-toluenesulfonic acid or the like. Reaction in the second stage In the second stage of reaction, the derivative (I') is alkylated by using an alkylating agent in an amount of 1.0 to 10 equivalents, preferably 1.0 to 5.0 equivalents to the derivative (I'). As alkylating agent, there can be used, for instance, alkylsulfuric acids such as dimethylsulfuric acid and diethylsulfuric acid; and alkyl halides such as methyl chloride, ethyl chloride, methyl bromide, ethyl bromide, methyl iodide and ethyl iodide, formylating agents such as formaldehyde or paraformaldehyde and haloalkylating agents such as paraformaldehyde-hydrogen chloride or paraformaldehyde-hydrogen bromide. The reaction can proceed without solvent, but usually a solvent is used to accelerate the reaction. As the solvents usable for the said purpose in the above reaction, aliphatic hydrocarbons such as hexane, heptane, ligroine and petroleum ether; aromatic hydrocarbons such as benzene; toluene, xylene and chlorobenzene; halogenated hydrocarbons such as chloroform and methylene chloride; ethers such as diethyl ether, dioxane and tetrahydrofuran; ketones such as acetone and methyl ethyl ketone; nitriles such as acetonitrile and isobutyronitrile; tertiary amines such as pyridine and N,N-diethylaniline; acid amides such as formamide, N,N-dimethylformamide and N-methylpyrrolidone; sulfur-containing compounds such as dimethyl sulfoxide and sulfolane; water and mixtures thereof may be exemplified. Among them, the aliphatic hydrocarbons, the acid amides, the sulfur-containing compounds and mixtures thereof are preferred. In the above reaction, usually a base is used in an amount of 1.0 to 10 equivalents, preferably 1.0 to 2.0 equivalents to the derivative (I'). As base, there can be used organic bases containing nitrogen such as pyridine, triethylamine and 1,4-diazabicyclo-2,2,2-octane; and inorganic bases such as sodium hydride, potassium hydride, sodium hydroxide, potassium hydroxide, sodium carbonate and potassium carbonate. Among them, such inorganic bases as sodium hydride and potassium carbonate are preferred. Reaction temperature is usually from 0 to 150°C, preferably from room temperature to reflux temperature of the reaction mixture. Reaction time is usually 10 minutes to 96 hours, preferably 30 minutes to 48 hours. (2) According to Scheme 2, N-phenyl carbamate (VIII) in which G 2 is C 1-4 alkyl or phenyl is reacted with β-aminoacrylic ester (V) to form an uracil derivative (I') at the first stage, and after isolating the derivative (I') or without isolation thereof, the 1-position of the uracil ring thereof is alkylated to produce an uracil derivative of the formula (I) at the second stage. Reaction in the first stage Usually N-phenyl carbamate (VII) is used in an amount of 0.5 to 1.5 equivalents, preferably 0.9 to 1.1 equivalents to β-aminoacrylic ester (V). Usually a solvent is required to be present in the reaction. As solvent, there can be used, for instance, aliphatic hydrocarbons such as hexane, heptane, ligroine and petroleum ether; aromatic hydrocarbons such as benzene, toluene, xylene and chlorobenzene; halogenated hydrocarbons such as chloroform and methylene chloride; ethers such as diethyl ether, dioxane and tetrahydrofuran; ketones such as acetone and methyl ethyl ketone; nitriles such as acetonitrile and isobutyronitrile; tertiary amines such as pyridine and N,N-diethylaniline; acid amides such as formamide, N,N-dimethylformamide and N-methylpyrrolidone; sulfur-containing compounds such as dimethyl sulfoxide and sulfolane; alcohols such as methanol, ethanol, propanol and butanol; water; and mixtures thereof. Among them, the aliphatic hydrocarbons, the acid amides, the sulfur-containing compounds and mixtures thereof are preferred. In the above reaction, usually a base is used in an amount of 0.5 to 10 equivalents, preferably 1.0 to 2.0 equivalents to β-aminoacrylic ester (V). The bases usable in the above reaction include inorganic bases such as sodium hydride, potassium hydride, sodium hydroxide, potassium hydroxide, sodium carbonate and potassium carbonate; metal alcoholates such as sodium methoxide, sodium ethoxide and potassium-tert-butoxide; and metal alkyl mercaptides such as sodium methyl mercaptide and sodium ethyl mercaptide. Among them, inorganic bases such as sodium hydride and metal alcoholates such as sodium methoxide are preferred. The reaction is carried out at a temperature of usually from 0 to 200°C, preferably from room temperature to reflux temperature of the reaction mixture. Reaction time is usually 10 minutes to 72 hours, preferably 30 minutes to 12 hours. After the completion of the reaction, the derivative (I') can be isolated from the reaction mixture by acidifying it with a mineral acid such as hydrochloric acid or an organic acid such as acetic acid, trifluoroacetic acid and p-toluenesulfonic acid. Reaction in the second stage Alkylation of the derivative (I') can be effectuated under the same reaction conditions as in the second stage of Scheme 1. (3) In Scheme 3, phenyl iso(thio)cyanate (VI) is reacted with N-substituted-β-aminoacrylic ester (VIII) in which G 1 is C 1-4 alkyl or phenyl to produce an uracil derivative of the formula (I) in a single stage. It is possible to employ the same reaction conditions as used in Scheme 1. (4) In Scheme 4 N-phenyl carbamate (VII) is reacted with N-substituted-β-aminoacrylic ester (VIII) to produce an uracil derivative of the formula (I) in a single stage. The reaction can be performed under the same reaction conditions as used in Scheme 2. The uracil derivatives of the present invention can be applied as a herbicide for upland field, paddy fields and non-arable land through either soil treatment or foliage treatment. Also, they show high herbicidal activities at a low dosage against, for instance, broad-leaved weeds of Solanaceae weeds such as Solanum nigrum and Datura nigrum , Malvaceae weeds such as Abutilon theophrasti and Side spinosa , Convolvulaceae weeds such as Ipomoea spps. of Ipomoea purpurea , and Calystegia spps., Amaranthaceae weeds such as Amaranthus lividus and Amaranthus retroflexus , Compositae weeds such as Xanthium pensylvanicum , Ambrosia artemisiaefolia , Helianthus annus , Galinsoga ciliata , Cirsium arvense , Senecio vulgaris and Erigeron annus , Crucifereae weeds such as Rorippa indica, Sinapis arvensis and Capsella Bursapastris , Polyzonaceae weeds such as Polygonum Blume and Polygonum convolvulus , Portulacaceae weeds such as Portulaca oleracea , Chenopodiaceae weeds such as Chenopodium album , Chenopodium ficifolium and Kochias coparia , Caryophyllaceae weeds such as Stellaria media , Scrophulariaceae weeds such as Veronica persica , Commelinaceae weeds such as Commelina communis , Labiatae weeds such as Lamium amplexicaule and Lamium purpureum , Euphorbiaceae weeds such as Euphorbia supina and Euphorbia maculata , Rubiaceae weeds such as Galium spurium , Galium aparine and Rubiaakane , Violaceae weeds such as Viola arvensis , and Leguminosae weeds such Sesbania exaltata and Cassia obtusifolia ; Graminaceous weeds such as Sorgham bicolor , Panicum dichotomiflorum , Sorphum halepense , Echinochloa crus-galli , Digitariaadscendens , Avena fatua , Eleusine indica , Setaria viridis and Alopecurus aequalis ; Cyperaceous weeds such as Cyperus rotundus ; and paddy weeds of Alismataceae weeds such as Alisma canaliculatum , Sagittaria trifolia and Sagittaria pygmaea , Cyperaceae weeds such as Cyperus difformis , Cyperus serotinus , Scirpus juncoides and Eleocharis kuroguwai , Scrothulariaceae weeds such as Lindemia pyxidaria , Potenderiaceae weeds such as Monochoria Vaginalis , Potamogetonaceae weeds such as Potamogeton distinctus , Lythraceae weeds such as Rotala indica and Gramineae weeds such as Echinochloa crus-galli . It is also quite remarkable that the uracil derivatives of the present invention do no harm to the important crops such as wheat, corn, barley, soybean, rice, cotton, sugar beet and sorghum. Further, the uracil derivatives of the present invention are also useful as a defoliant. In use of the compounds of present invention as a herbicide, they are usually mixed with a carrier, for example, a solid carrier such as clay, talc, bentonite, diatomaceous earth and white carbon (fine silica powder), or a liquid carrier such as water, alcohols (e.g. isopropanol, butanol, benzyl alcohol or furfuryl alcohol), aromatic hydrocarbons (e.g. toluene or xylene), ethers (e.g. anisole) ketones (e.g. cyclohexanone or isophorone), esters (e.g. butyl acetate), acid amides (e.g. N-methylpyrrolidone) and halogenated carbons (e.g. chlorobenzene). Also, if necessary, they may be added with a suitable adjuvant such as surfactant, emulsifier, dispersant, penetrating agent, spreader, thickener, anti-freezing agent, coagulation preventing agent or stabilizer, and can be offered to practical use in various forms of formulation such as liquid formulation, emulsifiable concentrate, wettable powder, dry flowable, flowable, dust and granules. The compounds of present invention may be mixed, if necessary, with, for example, other kinds of herbicide, various kinds of insecticide, fungicide, plant growth regulating agent or synergism agent in the course of preparation or at the time of application of the formulation. As the kinds of herbicide that can be mixed with the compounds of present invention in use thereof, there can be mentioned, for instance, the compounds described in Farm Chemicals Handbook, 1989. The application rate of the compound of the present invention is variable depending on, for example, the place of application, time of application, method of application, kind of crop to be treated, but it is usually appropriate to apply the compound of the present invention in an amount of about 0.0001 to 10 kg/ha, preferably 0.001 to 5 kg/ha measured as the amount of active ingredient. The compounds of the present invention, as compared with the conventional herbicides, have a rapid and high herbicidal effect at a very low dosage and can be applied through either soil treatment or foliage treatment against a wise variety of weeds. The present invention is now further described in the following Examples. Reference Examples B-1, B-2, C-1 and C-2 illustrate the preparation of compounds which are similar to those of the present invention. REFERENCE EXAMPLE B-1 Synthesis of 3-(4-chloro-2-fluoro-5-methoxycarbonylmethylthiophenyl)-1-methyl-6-trifluoromethyl-2,4(1H,3H)-pyrimidinedione (compound B-1) To a suspension of 0.16 g of sodium hydride (purity: 55%) in 5 ml of dimethylformamide, a solution of 1.5 g of 3-(4-chloro-2-fluoro-5-methoxycarbonylmethylthiophenyl)-6-trifluoromethyl-2,4(1H,3H)-pyrimidinedione in 10 ml of dimethylformamide was added dropwise at room temperature. After evolution of hydrogen ceased, 0.59 g of dimethylsulfuric acid was added and the resultant solution was stirred at room temperature for 3 hours. The reaction mixture was poured into 300 ml of water and extracted twice with ethyl acetate. The extract was washed with a saturated sodium chloride aqueous solution and dried over anhydrous sodium sulfate, and then ethyl acetate was distilled off to obtain a crude product. The obtained product was purified by preparative thin-layer chromatography (developing solvent: CHCl 3 ) and then by preparative high performance liquid chromatography [eluent: CHCN/H 2 O (5 : 1)] to obtain 0.1 g of the objective compound as viscous oil. REFERENCE EXAMPLE B-2 Synthesis of 3-(4-chloro-2-fluoro-5-methoxycarbonylmethylthiophenyl)-6-trifluoromethyl-2,4(1H,3H)-pyrimidinedione (compound B-2) A solution of 4.75 g of ethyl 3-amino-4,4,4-trifluorocrotonate in 50 ml of anhydrous toluene was added dropwise to a solution prepared by suspending 1.14 g of sodium hydride (purity: 55%) in 110 ml of dimethylformamide. Said dropwise addition was conducted at 0°C under stirring over a period of 15 minutes. The resulting mixture was further stirred at 0°C for 15 minutes. Then the reaction mixture was cooled to -30°C, and a solution of 6.9 g of 4-chloro-2-fluoro-5-methoxycarbonylmethylthiophenyl isocyanate in 50 ml of anhydrous toluene was added dropwise thereto. The resulting reaction mixture was returned to room temperature and stirred for 2 hours. After distilling off the solvent, the residual solution was added with ethyl acetate, washed twice with a solution of 20 ml of 2N hydrochloric acid and 500 ml of water, washed with a saturated sodium chloride aqueous solution, and dried over anhydrous sodium sulfate, and then ethyl acetate was distilled off to obtain a crude product. This crude product was preliminarily purified by silica gel column chromatography using CHCl 3 as developing solvent and then purified by silica gel column chromatography using ethyl acetate/hexane (3 : 1) as developing solvent to obtain 1.5 g of the objective compound as viscous oil. REFERENCE EXAMPLE C-1 Synthesis of 3-(4-chloro-2-fluoro-5-(5-methyl-1,3,4-oxadiazol-2-yl)phenyl)-1-methyl-6-trifluoromethyl-2,4(1H,3H)-pyrimidinedione (compound C-1) To a suspension of 0.31 g of sodium hydride (oil, purity: 55%) in 13 ml of dimethylformamide, a solution of 2.5 g of 3-(4-chloro-2-fluoro-5-(5-methyl-1,3,4-oxadiazol-2-yl)phenyl)-6-trifluoromethyl-2,4(1H,3H)- pyrimidinedione in 20 ml of N,N-dimethylformamide was added dropwise at 25°C. After evolution of hydrogen ceased, 1.02 g of dimethylsulfuric acid was added over a period of 15 minutes. The mixed solution was stirred at room temperature for 2 hours and extracted with ethyl acetate by adding water. The extract was dried over anhydrous sodium sulfate. Then the solvent was distilled off and the residue was purified by preparative high performance liquid chromatography using acetonitrile/water (5 : 1) as eluent to obtain 0.78 g of the objective compound. REFERENCE EXAMPLE C-2 Synthesis of 3-(4-chloro-2-fluoro-5-(5-methyl-1,3,4-oxadiazol-2-yl)phenyl)-6-trifluoromethyl-2,4(1H,3H)-pyrimidinedione (compound C-2) To a suspension of 1.04 g of sodium hydride (oil, purity: 55%) in 75 ml of dimethylformamide, a solution of 4.3 g of ethyl 3-amino-4,4,4-trifluorocrotonate in 58 ml of toluene was added dropwise at 0°C over a period of 15 minutes. Thereafter, the solution was stirred at 0°C for 15 minutes and then cooled to -30°C, followed by dropwise addition of a solution of 5.7 g of 4-chloro-2-fluoro-5-(5-methyl-1,3,4-oxadiazol-2-yl)phenyl isocyanate in 60 ml of toluene. The resulting mixed solution was stirred at room temperature for 3 hours. Then the solvent was distilled off under reduced pressure and the resultantly obtained oily substance was added with a solution of 13.3 ml of 2N hydrochloric acid and 300 ml of water and extracted twice with ethyl acetate. The ethyl acetate layer was washed with a saturated sodium chloride aqueous solution and dried over anhydrous sodium sulfate. Then the solvent was distilled off and the resulting crude product was purified by preparative high performance liquid chromatography using acetonitrile/water (5 : 1) as eluent to obtain 1.78 g of the objective compound. The uracil derivatives synthesized according to the above Reference Examples or Schemes are shown in Tables 1-B and 1-C, and the physical properties of these compounds are shown in Tables 2-B and 2-C. Uracil derivatives of the present invention synthesized by following similar procedures to the above Reference Examples or Schemes are shown in the following Tables.

Claims: Claims for the following Contracting States : AT, BE, CH, LI, DE, DK, FR, GB, GR, IT, LU, NL, SE A uracil derivative of formula (I): wherein R 1 represents hydrogen, C 1-3 alkyl, hydroxymethyl or C 1-3 haloalkyl, R 2 represents C 1-6 haloalkyl, R 3 represents hydrogen, C 1-6 alkyl, C 1-6 haloalkyl, hydroxymethyl, halogen or nitro, R 4 represents hydrogen or halogen, R 5 represents halogen, nitro or cyano, R 6 represents [wherein D 21 represents hydrogen, C 1-3 alkyl, C 1-3 alkoxyl or C 1-3 alkoxy-C 1-2 alkyl, and D 22 represents hydrogen, C 1-4 alkyl, C 3-6 cycloalkyl, C 2-3 haloalkyl, phenyl or benzyl]; [wherein D 21 and D 22 are as defined above, and D 23 represents hydrogen or C 1-3 alkyl]; or [wherein D 25 represents hydrogen, sodium, C 1-4 alkyl, C 2-5 alkenyl, C 3-5 alkynyl, C 2-5 acyl, C 1-4 alkylsulfonyl or C 1-3 alkoxy-C 1-2 alkyl, and D 26 represents C 1-4 alkyl or C 1-3 haloalkyl]; and X represents oxygen or sulfur. A uracil derivative according to claim 1 which is of formula IV: wherein R 1 represents hydrogen, C 1-3 alkyl or C 1-3 haloalkyl, R 2 represents C 1-6 haloalkyl, R 3 represents hydrogen, C 1-6 alkyl, C 1-6 haloalkyl, hydroxymethyl, halogen or nitro, R 4 represents hydrogen or halogen, R 5 represents halogen, nitro or cyano, D 1 represents [wherein D 21 represents hydrogen, C 1-3 alkyl, C 1-3 alkoxyl or C 1-3 alkoxy-C 1-2 alkyl, and D 22 represents hydrogen, C 1-4 alkyl, C 3-6 cycloalkyl, C 2-3 haloalkyl, phenyl or benzyl], [wherein D 21 and D 22 are as defined above, and D 23 represents hydrogen, or C 1-3 alkyl]; or [wherein D 25 represents hydrogen, sodium, C 1-4 alkyl, C 2-5 alkenyl, C 3-5 alkynyl, C 2-5 acyl, C 1-4 alkylsulfonyl or C 1-3 alkoxy-C 1-2 alkyl, and D 26 represents C 1-4 alkyl or C 1-3 haloalkyl]; and X represents oxygen or sulfur. A uracil derivative of formula: wherein R 2 represents halomethyl, R 4 represents halogen, R 5 represents halogen, and D 26 represents C 1-4 alkyl or halomethyl. A uracil derivative according to claim 3 which is of formula: wherein D 26 represents methyl or ethyl. A herbicidal composition comprising a uracil derivative as defined in any one of claims 1 to 4 and a herbicidally acceptable carrier or diluent. A process for producing a uracil derivative as defined in any one of claims 1 to 4 which comprises: (1) reacting phenyl iso(thio)cyanate of formula (VI): in which R 4 , R 5 , R 6 and X are as defined above, with a β-aminoacrylic ester of formula (V): in which R 2 and R 3 are as defined above and G 1 represents C 1-4 alkyl or phenyl, to form a compound of formula (I'): and, if desired, the compound of formula (I') is reacted with an alkylating agent to form a compound of formula (I) as defined above in which R 1 represents C 1-3 alkyl, hydroxymethyl or C 1-3 haloalkyl; (2) reacting an N-phenyl carbonate of formula (VII): in which R 4 , R 5 , R 6 and X are as defined above and G 2 represents C 1-4 alkyl or phenyl, with a β-aminoacrylic ester of formula (V) as defined above to form a compound of formula (I') as defined above, and, if desired, the compound of formula (I') is reacted with an alkylating agent to form a compound of formula (I) as defined above in which R 1 represents C 1-3 alkyl, hydroxymethyl or C 1-3 haloalkyl; (3) reacting phenyl iso(thio)cyanate of formula (VI) as defined above with an N-substituted-β-aminoacrylic ester of formula (VIII): in which G 1 is as defined above, R 2 and R 3 are as defined above and R 1 represents C 1-3 alkyl, hydroxymethyl or C 1-3 haloalkyl, to form a compound of formula (I) as defined above in which R 1 is as defined above; or (4) reacting an N-phenyl carbamate of formula (VII) as defined above with an N-substituted-β-aminoacrylic ester of formula (VIII) as defined above to form a compound of formula (I) as defined above in which R 1 represents C 1-3 alkyl, hydroxymethyl or C 1-3 haloalkyl. A method for controlling the growth of weeds at a locus which comprises applying thereto a uracil derivative as defined in any one of claims 1 to 4. A method according to claim 7 wherein the locus contains wheat. Claims for the following Contracting State : ES A process for producing a uracil derivative of formula (I): wherein R 1 represents hydrogen, C 1-3 alkyl, hydroxymethyl or C 1-3 haloalkyl, R 2 represents C 1-6 haloalkyl, R 3 represents hydrogen, C 1-6 alkyl, C 1-6 haloalkyl, hydroxymethyl, halogen or nitro, R 4 represents hydrogen or halogen, R 5 represents halogen, nitro or cyano, R 6 represents [wherein D 21 represents hydrogen, C 1-3 alkyl, C 1-3 alkoxyl or C 1-3 alkoxy-C 1-2 alkyl, and D 22 represents hydrogen, C 1-4 alkyl, C 3-6 cycloalkyl, C 2-3 haloalkyl, phenyl or benzyl]; [wherein D 21 and D 22 are as defined above, and D 23 represents hydrogen or C 1-3 alkyl]; or [wherein D 25 represents hydrogen, sodium, C 1-4 alkyl, C 2-5 alkenyl, C 3-5 alkynyl, C 2-5 acyl, C 1-4 alkylsulfonyl or C 1-3 alkoxy-C 1-2 alkyl, and D 26 represents C 1-4 alkyl or C 1-3 haloalkyl]; and X represents oxygen or sulfur, which process comprises: (1) reacting phenyl iso(thio)cyanate of formula (VI): in which R 4 , R 5 , R 6 and X are as defined above, with a β-aminoacrylic ester of formula (V): in which R 2 and R 3 are as defined above and G 1 represents C 1-4 alkyl or phenyl, to form a compound of formula (I'): and, if desired, the compound of formula (I') is reacted with an alkylating agent to form a compound of formula (I) as defined above in which R 1 represents C 1-3 alkyl, hydroxymethyl or C 1-3 haloalkyl; (2) reacting an N-phenyl carbonate of formula (VII): in which R 4 , R 5 , R 6 and X are as defined above and G 2 represents C 1-4 alkyl or phenyl, with a β-aminoacrylic ester of formula (V) as defined above to form a compound of formula (I') as defined above, and, if desired, the compound of formula (I') is reacted with an alkylating agent to form a compound of formula (I) as defined above in which R 1 represents C 1-3 alkyl, hydroxymethyl or C 1-3 haloalkyl; (3) reacting phenyl iso(thio)cyanate of formula (VI) as defined above with an N-substituted-β-aminoacrylic ester of formula (VIII): in which G 1 is as defined above, R 2 and R 3 are as defined above and R 1 represents C 1-3 alkyl, hydroxymethyl or C 1-3 haloalkyl, to form a compound of formula (I) as defined above in which R 1 is as defined above; or (4) reacting an N-phenyl carbamate of formula (VII) as defined above with an N-substituted-β-aminoacrylic ester of formula (VIII) as defined above to form a compound of formula (I) as defined above in which R 1 represents C 1-3 alky, hydroxymethyl or C 1-3 haloalkyl. A process according to claim 1, wherein said uracil derivative of formula (I) is of formula IV: wherein R 1 represents hydrogen, C 1-3 alkyl or C 1-3 haloalkyl, R 2 represents C 1-6 haloalkyl, R 3 represents hydrogen, C 1-6 alkyl, C 1-6 haloalkyl, hydroxymethyl, halogen or nitro, R 4 represents hydrogen or halogen, R 5 represents halogen, nitro or cyano, D 1 represents [wherein D 21 represents hydrogen, C 1-3 alkoxyl or C 1-3 alkoxy-C 1-2 alkyl, and D 22 represents hydrogen, C 1-4 alkyl, C 3-6 cycloalkyl, C 2-3 haloalkyl, phenyl or benzyl], [wherein D 21 and D 22 are as defined above, and D 23 represents hydrogen or C 1-3 alkyl]; or [wherein D 25 represents hydrogen, sodium, C 1-4 alkyl, C 2-5 alkenyl, C 3-5 alkynyl, C 2-5 acyl, C 1-4 alkylsulfonyl or C 1-3 alkoxy-C 1-2 alkyl, and D 26 represents C 1-4 alkyl or C 1-3 haloalkyl]; and X represents oxygen or sulfur. A process according to claim 1, wherein said uracil derivative is of formula: wherein R 2 represents halomethyl, R 4 represents halogen, R 5 represents halogen, and D 26 represents C 1-4 alkyl or halomethyl. A process according to claim 1, wherein said uracil derivative is of formula: wherein D 26 represents methyl or ethyl. A process for producing a herbicidal composition, which comprises mixing together a uracil derivative as defined in any one of claims 1 to 4 and a herbicidally acceptable carrier or diluent. A method for controlling the growth of weeds at a locus, which comprises applying thereto a uracil derivative of formula (I) as defined in any one of claims 1 to 4. A method according to claim 6 wherein the locus contains wheat.

Inventors: FUKUDA KENZOU, ITOH KAORU, NAWAMAKI TSUTOMU, SATOW JUN, SUZUKI KOICHI, WATANABE SHIGEOMI, FUKUDA, KENZOU,, ITOH, KAORU,, NAWAMAKI, TSUTOMU,, SATOW, JUN,, SUZUKI, KOICHI,, WATANABE, SHIGEOMI,, FUKUDA, KENZOU, C/O NISSAN CHEMICAL IND. LTD., ITOH, KAORU, C/O NISSAN CHEMICAL IND. LTD., NAWAMAKI, TSUTOMU, C/O NISSAN CHEMICAL IND. LTD., SATOW, JUN, C/O NISSAN CHEMICAL IND. LTD., SUZUKI, KOICHI, C/O NISSAN CHEMICAL IND. LTD., WATANABE, SHIGEOMI, C/O NISSAN CHEMICAL IND. LTD.
Applicants: NISSAN CHEMICAL IND LTD, NISSAN CHEMICAL INDUSTRIES, LIMITED
Application year: 1990
Main classification: C07D413
IPC codes: A01N43, C07D413, C07D417, C07D403, C07D239