DIPHENYL ETHER HERBICIDES

Abstract: Herbicidal compositions comprising, as active ingre­ dient, a diphenyl ether derivative of formula wherein R₁ represents a hydrogen or halogen atom or an alkyl or haloalkyl group; R₂ and R₃ each independently represents a hydrogen or halogen atom or an alkyl, haloalkyl, nitro or cyano group; and the substituents A and B have the meanings as defined in the text; the use of such diphenyl ethers as herbicides; certain novel diphenyl ethers within formula I and their preparation.

Description: EIPHENYL ETHER HERBICIDES This invention relates to a osmpositicn for and a method of controlling undesired plant growth and to compounds for use in such a compositlon or method. Certain substituted phenoxy phthalates are disclosed as herbicides in US Patent 4334915, along with the corresponding phenoxy phthalic anhydride. That anhydride is disclosed only as being a useful intermediate in the preparation of the phthalates and no rtention or suggestion is made that the anhydride itself may exhibit any biological activity. It has now been found that such phenoxy phthalic anhydrides, along with certain other diphenyl ethers which bear a fused ring substituent at the 3,4 position, show interesting herbicidal activity. Accordingly, the present invention provides a herbicidal composition which coMprises a carrier and, as active ingredient, a diphenyl ether derivative having the general formula I: EMI1.1 wherein h represents a hydrogen or halogen, preferably chlorine, atan or an alkyl or haloalkyl, preferably trifluoromethyl, group; RI and R3, which may be the same or different, each independently represents a hydrogen or halogen, preferably chlorine, atom or an alkyl, haloalkyl, nitro or cyano group; ; A and B, which may be the sane or different, each independently represents a diva lent group selected from EMI1.2 provided that when A ifferent fran A and each R4, which may be the same or different, represents a hydrogen or halogen atan or an optionally substituted alkyl, cycloalkyl, alkyl, altynyl, aryl, suitably phenyl, aralkyl, alkaryl, alkyl cycloalkocy, alkenyloxy, alkynyloxy, alkoxycarbonylalkoxyl, alkylthio, acyl, acyloxy, carbooxyl, alkoxycarbonyl or heterocyclic group, amino group of formula NR6Rl, or when one R4 represents a hydrogen atari, an alkoxy group or a hydrocarbon group, then the other may represent a hydroxy group, or both groups R4 together may represent an imino group of formula R5 represents a hydrogen atam, a carboxyl or hydroxyl group, or an optionally substituted alkyl, alkoxy, aralkyl, alkoxycarbonyl or alkoxycarbonylalkyl group, or an amino group of formula and R7, , which may be the sane or different, each represents a hydrogen atdm or an optionally substituted alkyl, aryl or acyl group; and X, both in formula I and in the definitions of the substituents therein, represents an oxygen or sulphur atom. The term "acyl" is used herein to denote the radical derived from an organic acid by the removal of a hydroxy group; the organic acid may be a carboxylic acid (including carbamic acid derivatives) or a sulphonic acid, examples of suitable acyl groups being alkylcarbonyl, alkylcarbamoyl and alkylsulphonyl, e.g. acetyl, methylsulphonyl and dimethylcarbamoyl. When any of the foregoing substituents represents or contains an allyl, alkenyl or alkynyl substituent group, this may be linear or branched and may contain up to 10, preferably up to 6, carbon atoms, suitable examples being methyl, ethyl, propyl, ally-l and proynyl. When they represent or contain a cycloalkyl substituent group this may contain fran 3 to 10, preferably 5 to 8, carbon atoms, and is suitably cyclohexyl. When they contain a haloalkyl substituent group, this suitably contains up to 6, preferably up to 4, carbon atoms and the halogen atom is suitably fluorine or chlorine, trifluorarethyl being particularly preferred. When they contain an aryl substituent group, this is preferably a phenyl group. When they contain a heterocyclic group, this may, for example, be a pyrrole, pyrrolidine, pyridine, piperidine, furan or pyran ring. When any of the foregoing substituents are designated as being optionally substituted, the substituent groups which are optionally present may be any of those customarily employed in the development of pesticidal ccmpoNnds, and/or the modification of such compounds to influence their structure/activity, persistence, penetration or other property. Specific examples of such substituents include halogen, especially chlorine, atoms and nitro, cyano, hydroxyl, alkoxy, e.g. methoxy, or ester, e.g. alkoxycarbonyl, groups. Preferred compositions are those wherein the active ingredient is a compound of general formula I wherein X represents an oxygen atom; A represents an oxygen atom, a carbonyl group, the group C(R4)2 wherein one group R4 is a hydrogen atcan, or an alkyl or alkoxy group of up to 4 carbon atoms, especially methyl or methoxy, or an aryl, especially phenyl, group, and the other group R4 is a hydrogen or halogen, especially chlorine or bromine, atan, a hydroxyl group, an alkyl group of up to 4 carbon atoms, especially methyl, an alkoxy group of up to 4 carbon atoms, especially methoxy, ether or propoxy, optionally substituted by a halogen, especially chlorine, atom, or a hydroxy or alkoxy, especially iretbocy, group, a cycloalkoxy group of 5 to 8 carbon atans especially cyclohexyloxy, an alkenyloxy or alkynyloxy group of up to 6 carbon atoms, especially allyloxy or proynyloxy, an alkoxycarbanylalkoxy, especially et-hoxycarbonylethoxy, group, an alkylthio group of up to 4 carbon atoms, especially methyl- or propyl- thio, an alkanoyl, especially acetyl, group, a pyridyl group, or an amino group of formula NR6R7 wherein R6 represents a hydrogen atcan or an alkyl group of up to 4 carbon atoms, especially methyl, and RI represents an alkyl group of up to 4 carbon atoms, especially methyl, a phenyl group optionally substituted by at least one halogen, especially chlorine, atom, or an aikylcarbonyl, alkylcarbamoyl or alkylsulphonyl group, especially acetyl, dimethylcarbamoyl or methylsulphonyl; and B represents an oxygen atom, the group C(R4)2 wherein each group R4, which may be the same or different, independently represents a hydrogen atom or an alkyl or alkoxy group of up to 4 carbon atoms, especially methyl or methoxy, or the group NR5 wherein R5 represents a hydrogen atom, an alkyl group of up to 4 carbon atoms, especially methyl, a benzyl group, or an alkoxy- carbonylalkyl group of up to 8 carbon atans, especially ethoxycarbonylmethyl or ethoxycarbonylethyl. Particularly preferred compositions are those wherein the active ingredient is a compound in which R1 represents a trifluaro- methyl group, R2 represents a halogen, especially chlorine, atom and R3 represents a hydrogen atan. With one exception, the compounds of formula I are novel, and the invention therefore also extends to those novel catponds per se. The novel carpuads are the diphenyl ether derivatives of formula I wherein the substituents A, B, R1, R2, R3, R4, R5, R6 and RI have the meanings defined above, with the exception of 4- (a-chloro-8-trif luorarethylphenoxy) -phthalic anhydride. It will be appreciated that when the nature of the substituents is such as to introduce an asymmetric carbon atom, then the resulting carpund will exist in stereoisomeric forms. Also, some substitutent combinations permit the existence of tautaneric forms. The scope of the present invention includes these different forms of the compounds and their mixtures, and herbicidal compositions containing the active ingredient in such isomeric forms and mixtures. The invention further provides a process for the preparation of the novel diphenyl ethers as defined above which comprises reacting a phthalide of formula: EMI4.1 with a compound of the formula: EMI5.1 wherein A, B, X, R1, R, and R3 have the meanings given above for formula I; one of Z and Q represents a halogen, suitably chlorine, atom or nitro group, and the other represents a group of formula -OM wherein M represents a hydrogen or alkali metal atom. Conveniently the reaction is carried out by reacting a compound of formula II wherein 9 is hydroxy with an alkali metal hydroxide in an alkanol, e.g. ethanol, solvent, thereby forming the corresponding alkali metal salt which is then reacted with a compound of formula III wherein Z represents a chlorine atom. The reaction of the said salt with the chloro- compound is preferably carried out in a suitable organic solvent, eg dimethyl sulphoxide, sulpholane, dimethyl formamide, or dimethyl acetamide at elevated temperature, e.g. above 250C and in particular between 400C and reflux, conveniently under reflux, and also under an inert atmosphere such as nitrogen. Carpounds wherein X in formula I represents sulphur may be obtained from the corresponding oxygen analogues by reaction with phosphorus pentasulphide. Compounds wherein A represents a halomethylene group may suitably be obtained by reacting the corresponding methylene compound with an appropriate halogenating agent. Thus, a compound wherein A represents a3Br may be obtained by reacting the corresponding A=#CH2 compound with N-bromosuccinimide, suitably in the presence of a peroxide such as berizoyl peroxide and in a solvent such as carbon tetrachloride. Compounds wherein A represents a hydroxymethylene group may be obtained by hydrolysis of the corresponding halomethylene compound. Compounds wherein X and B in formula I both represent an oxygen atom, and A is the group C(R4)2 in which one group R4 is a hydrogen atari and the other has one of the meanings defined above excluding hydrogen or hydroxyl, may be obtained from the corresponding ccccound wherein A represents CH(OH) by reaction with a reagent of formula HR4 wherein R4 is as defined for formula I excluding hydrogen or hydroxyl or, when R4 is a carboxylic acyloxy group, an acyl anhydride of formula Ac2O wherein Ac is an alkylcarbonyl group. The reaction is suitably carried out by refluxing the reaction mixture. In some cases the reactant HR4 can be used in excess to provide a convenient reaction solvent; in other cases it may be convenient to introduce the reagent HR4 as a solution in an organic solvent, e.g. acetonitrile or methyl ethyl ketone. The compounds of the general formula I have been found to show interesting activity as herbicides. Accordingly the invention also provides the use as a herbicide of such a compound or composition according to the invention. Further in accordance with the invention there is provided a method of combating undesired plant growth at a locus by treating the locus with a compound or composition according to the invention. Application to the locus may be pre-ernergence or post-emergence. The dosage of active ingredient used may, for example, be frcm 0.05 to 4 kg/ha. A carrier in a ccmposition according to the invention is any material with which the active ingredient is formulated to facilitate application to the locus to be treated, which may for example be a plant, seed or soil, or to facilitate storage, transport or handling. A carrier may be a solid or a liquid, including a material which is normally gaseous but which has been compressed to form a liquid, and any of the carriers normally used in formulating herbicidal ccmpositions may be used. Preferably compositions according to the invention contain 0.5 to 958 by weight of active ingredient. Suitable solid carriers include natural and synthetic clays and silicates, for example natural silicas such as diatomaceous earths; magnesium silicates, for example talcs; magnesium aluminium silicates, for example attapulgites and vermiculites; aluminium silicates, for example kaolinites, irontomonllonites and micas; calcium carbonate; calcium sulphate; ammonium sulphate; synthetic hydrated silicon oxides and synthetic calcium or aluminium silicates; elements, for example carbon and sulphur; natural and synthetic resins, for example courone resins, polyvinyl chloride, and styrene polymers and ccpolymers; solid polychlorophenols; bitumen; waxes; and solid fertilisers, for example superphosphates. Suitable liquid carriers include water; alcohols, for example iscfprcpanol and glycols; ketones, for example acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohenanone; ethers; aranatic or araliphatic hydrocarbons, for example benzene, toluene and xylene; petroleum fractions, for example kerosine and light mineral oils; chlorinated hydrocarbons, for example carbon tetrachloride, perchloroethylene and trlchloro-ethane. Mixtures of different liquids are often suitable. Agricultural compositions are often formulated and transported in a concentrated form which is subsequently diluted by the user before application. The presence of small amounts of a carrier which is a surface-active agent facilitates this process of dilution. Thus preferably at least one carrier in a composition according to the invention is a surface-active agent. For example the composition may contain at least two carriers, at least one of which is a surface-active agent. A surface-active agent may be an emulsifying agent, a dispersing agent or a wetting agent; it may be nonionic or ionic. Examples of suitable surf ace-active agents include the sodium or calcium salts of polyacrylic acids and lignin sulphnnic acids; the condensation of fatty acids or aliphatic amines or amides containing at least 12 carbon atoms in the molecule with ethylene oxide and/or propylene oxide; fatty acid esters of gly, z glycerol, sortitan, sucrose or pentaerythritol; condensates of these with ethylene oxide and/or propylene oxide; condensation products of fatty alcohol or alkyl phenols, for example p-octylphenol or p-octylcresol, with ethylene oxide and/or propylene oxide; sulphates or sulphonates of these condensation products; alkali or alkaline earth mental salts, preferably sodium salts, of sulphuric or sulphonic acid esters containing at least 10 carbon atoms in the molecule, for example sodium lauryl sulphate, sodium secondary alkyl sulphates, sodium salts of sulphonated castor oil, and sodium alkylaryl sulphonates such as dodecylbenzene sulphonate; and polymers of ethylene oxide and copolymers of ethylene oxide and propylene oxide. The compositions of the invention may for example be foritulated as wettable powders, dusts, granules, solutions, emulsifiable concentrates, emulsions, suspension concentrates and aerosols. Wettable powders usually contain 25, 50 or 75% w of active ingredient and usually contain in addition to solid inert carrier, 3-10% w of a dispersing agent and, where necessary, 0-10% w of stabiliser(s) and/or other additives such as penetrants or stickers. Dusts are usually formulated as a dust concentrate having a similar ccpposition to that of a wettable powder but without a dispersant, and are diluted in the field with further solid carrier to give a composition usually containing d-10% w of active ingredient. Granules are usually prepared to have a size between 10 and 100 BS mash (1.676 - 0.152 rtrn), and may be manufactured by agglomeration or impregnation techniques. Generally, granules will contain d-75% w active ingredient and 0-10% w of additives such as stabilisers, surfactants, slow release modifiers and binding agents. The so-called "dry flowable powders" consist of relatively small granules having a relatively high concentration of active ingredient. Emulsielable concentrates usually contain, in addition to a solvent and, when necessary, co-solvent, 10-50% w/v active ingredient, 2-208 w/v emulsifiers and 0-20% w/v of other additives such as stabilisers, penetrants and corrosion inhibitors. Suspension concentrates are usually compounded so as to obtain a stable, non-sedienting flowable product and usually contain 10-75% w active ingredient, 0.5-15% w of dispersing agents, 0.1-10% w of suspending agents such as protective colloids and thixotropic agents, 0-10% w of other additives such as defoamers, corrosion inhibitors, stabilisers, penetrants and stickers, and water or an organic liquid in which the active ingredient is substantially insoluble; certain organic solids or inorganic salts may be present dissolved in the formulation to assist in preventing sedImentation or as anti-freeze agents for water. Aqueous dispersions and emulsions, for example ccppositions obtained by diluting a wettable powder or a concentrate according to the invention with water, also lie within the scope of the invention. The said emulsions may be of the water-in-oil or of the oil-in-water type, and may have a thick 'mayonnaise'-like consistency. The e composition of the invention may also contain other ingredients, for example other ccppounds possessing herbicidal, insecticidal or fungicidal properties. The following Examples illustrate the invention. Example 1 5-(2'-chloro-4'-trifluoromethyl phenoxy)phthalide 5-Hydrrr' phthalide (5.5g) was dissolved in ethanol (50ml), 2.5g potassium hydroxide added and the solution refluxed for 3 hours. The e solvent was removed, the residue e dissolved in dinethylsulphoxide (50 ml) and 8.2g of 3,4 dichlorobenzotri- fluoride added. This mixture was stirred under dry nitrogen at 1600C for 18 hours, after which it was cooled, poured onto ice, neutralised with dilute hydrochloric acid and the product extracted with methylene chloride to yield the desired product m.pt. 109-111 C. Analysis: Calc. for C15H803C1F3 C 54.8 H 2.48 Found C 54.8 H 2.58 Example 2 5-(2'-Chloro-4'-trifluoromethylphenoxy)-3- braro phthalide. The product of Ex. 1 (1.5g) and N-bromosuccinimide (0.82g) was dissolved in dry carbon tetrachloride (25 ml) and a small pellet of benzoyl peroxide added. The reaction mixture was refluxed with stirring under strong light, when succinimide began to precipitate. The mixture was cooled, filtered, washed with carbon tetrachloride and the solvent removed. Chromatographic separation (silica column; methylene chloride eluant) yielded a pale orange viscous oil as the desired product. Analysis: Calc for C15H7ClBrF3O3 C 44.2 H 1.7% Found C 44.2 H 1.9% Example 3 5-(2'-chloro-4'-trifluoromethylphenoxy)-1 tiiipphtalide The product of Example 1 (1.55g) and phosphorus pentasulphide (2. 2g) were refluxed in sodium dried dioxan (15ml) for 1 hour with stirring. The reaction mixture was cooled, filtered, dried, washed with methylene chloride, and chranatographically purified to yield a pale yellow solid, m.pt. 86-880C. Analysis Calc for C15H8ClO2SF3 C 52.2 H 2.3 Found C 51.8 H 2.3 Example 4 N-Benzyl-5-(2'-nitro-4'-trifluoromethylphenoxy) phthalimide S-Benzyl-5-hydrcxyphthalimide (0.84 g.) and potassium hydroxide (0.19 g.) were dissolved in ethanol (50 ml.) and the solvent was evaporated. The residue was dissolved in direthylsulphoxide (50 ml.) and 4-chloro-3-nitro benzotrifluoride (0.75 g.) was added. The mixture was heated at 1800C for six hours and pored into water. The mixture was extracted with ethyl acetate, the ethyl acetate layer was separated, dried and evaporated to yield a pale yellow oil. The oil crystallised fran ethanol as pale yellow prises m.pt. 166-1670C. Analysis Calc for C22H13F3N2O5 C 59.7 H 2.9 N 6.3 Found C 59.8 H 3.0 N 6.6 Example 5 N-Benzyl-5-(2'-chloro-4'-trifluoromethylphenoxy) phthalimide Following a similar procedure to that of Example 4, but using 3,4-dichlorobenzotrifluoride in place of 4-chloro-3-nitrcbenzotri- fluoride, the desired product was obtained as a white solid m.pt. 119-1210C. Analysis Calc for C22H13F3ClNO3 C 61.2 H 3.0 N 3.25% Found C 61.2 H 2.9 N 3.1% Example 6 5-(2'-chloro-4'-trifluoromethylphenoxy)-3 hydroxyphthalide The product of Example 2, was refluxed with 20 ml water for 3 days, and the reaction mixture extracted with methylene chloride and dried. Removal of the solvent and chromatographic purification yielded the desired product, m.pt. 145-147 C. Analysis Calc for C15H804C1F3 C 52.2 H 2.3% Found C 51.9 H 2.4% Example 7 5-(2'-chloro-4'-trifluoromethylphenoxy)-3-methoxy phthalide A) 5-Hydroxy phthalide (5.5g) was dissolved in ethanol (50ml), 2. 5g potassium hydroxide added and the solution refluxed for 3 hours. The solvent was removed, the residue dissolved in dimethylsulphoxide (50ml) and 8.2g of 3,4-dichlorobenzotri fluoride added. This mixture was stirred under dry nitrogen at 160 C for 18 hours, after which it was cooled, poured onto ice, neutralised with dilute hydrochloric acid and the product extracted with methylene chloride. B) The product of A (1.5g) and N-bromosuccinimide (0.82g) was dissolved in dry carbon tetrachloride (25ml) and a small pellet of kenzoyl peroxide added. The reaction mixture was refluxed with stirring under strong light, when succinimide began to precipitate. The mixture was cooled, filtered, washed with carbon tetrachloride and the solvent removed. Chromatographic separation (silica column; methylene chloride eluant) yielded a pale orange viscous oil. C) The product of B was refluxed with 20ml water for 3 days, and the reaction mixture extracted with ethylene chloride and dried. Removal of the solvent and chromatographic purification yielded 5-(2'-chloro-4'-trifluoromethyl phenoxy) -3-hydroyphthalide m.pt. 145-147 C. This product is referred to in the following Examples 8-10 as "hydroxy phthalide". D) Hydroxyphthalide prared U in steps A)"C) above (1.4g) was refluxed is ;nsthanol (20ml) with stirring for 2 hours. Residual solvent was removed by evaporation, the product chromatographically purified over silica with methylene bichloride eluant to yield a clear oil, wmich was recrystallised to give the desired product, m.pt. 67 C. analysis Calc. for C16H10ClF3O4: C 53.6; H 2.8; Cl 9.9% Found C 53.6; H 2.9; Cl 9.9% Example 8 5-(2'-chloro-4'-trifluoromethylphenoxy)-3 acetoxy phthalide Hydroxyphthalide, (0.7g) was refluxed in acetic anhydride (10ml) with stirring for 5 hours. Excess acetic anhydride was removed by evaporation, the residue washed with saturated sodium bicarbonate solution, extracted with methylene dichloride and the organic layers washed with bicarbonate and dried with sodium sulphate. The solvent was removed, the product chromatographically purified and recrystallised to yield a solid, m.pt. 1130C. Analysis Calc. for C17H10ClF3O5: C 52.8; H 2.68 Found : C 53.0; H 2.78 Example 9 5-(2'-chloro-4'-trifluoromethylphenoxy)-3 N',N' dimethylureido phthalide Hydroxyphthalide (0.7g) was added to a solution of 1,1 dimethyl urea (0.2g) in methyl ethyl ketone (20ml) and the mixture refluxed for 2 hours, after which a further 0.2g of the urea were added. After a further 6 hours reflux, the solvent was removed, the residue suspended in water and shaken to remove any unreacted urea, taken up in ethyl acetate and chromatographically purified to yield a solid, m.pt. 1540C. Analysis Calc. for C18H14N2O4ClF3: C 52.7; H 3.4; N 6.8% Found : C 52.0; H 3.2; N 6.48 Example 10 5-(2'-chloro-4'-trifluoromethylphenoxy)-3 3,4-dichloroanilino phthalide Hydroxyphthalide (1. Og) was added to a solution of 3,4-dichloroaniline (0.5g) in dry acetonitrile (10ml), and a crystal of p.toluene sulphonic acid added. The mixture was refluxed with stirring for 55 hours, the solvent removed, and the residue chromatographically purified to yield a solid, m.pt. 1680C. Analysis Calc. for C21H11NO3C13F3: C 51.6; H 2.2; N 2.9 Found : C 51.6; H 2.1; N 2.7 Example 11-40 Following procedures similar to those described in the foregoing Examples, further compounds were prepared whose characteristics and analyses are set out in Table 1. In all cases, the identity of the product was confirmed by n.m.r. analysis. In those instances marked "m.m.s." the empirical formula was confirmed by accurate mass mEasurement spectrometry. The compounds are identified by reference to substituent R2, A and B in the following formula: EMI13.1 Table 1 Example No. A B R2 m.pt. C Analysis 11 CH2 O NO2 104-105 Calc. C 53.1 H 2.4 N 4.1% Found C 53.0 H 2.4 N 4.1% 12 CH2 O CN 109-111 Calc. C 60.2 H 2.5 N 4.4% Found C 59.5 H 2.4 N 4.0% 13 CH2 N-Benzyl Cl Yellow Oil Calc. C 63.2 H 3.6 N 3.4% Found C 63.3 H 3.5 N 3.7% 14 CO O Cl 74-75 Calc. C 52.6 H 1.7% Found C 52.3 H 1.3% 15 CHSC3H7 O Cl 85 Calc. C 53.7 H 3.5 Found C 53.5 H 3.4 16 CHOC2H5 O Cl Oil Calc. C 54.8 H 3.2 Found C 54.9 H 3.2 17 CHOC3H7 O Cl Oil Calc. C 55.9 H 3.6 Found C 56.0 H 3.7 18 CHOC3H7 O Cl Oil Calc. C 55.9 H 3.6 Found C 55.9 H 3.8 19 CHOCH2CH=CH2 O Cl Oil Calc. C 56.2 H 3.1 Found C 56.3 H 3.3 Table 1 continued... Example No. A B R2 m.pt. C Analysis 20 CHOCH2C=CH O Cl Oil Calc. C 56.4 H 2.6 Found C 56.7 H 2.8 21 CHOC6H11 O Cl 99-100 Calc. C 59.1 H 4.2 Found C 58.9 H 4.1 22 CHNHSO2CH3 O Cl 234-238 Calc. C 45.6 H 2.6 N 3.3 Found C 45.1 H 2.9 N 3.4 23 CHNHCOCH3 O Cl 234-6 Calc. C 52.9 H 2.9 N 3.6 Found C 52.4 H 2.7 N 3.5 24 CHOCH(CH3)- O Cl Oil Calc. C 54.8 H 3.2 COOC2H5 Found C 54.2 H 3.2 (Isomer 2) 25 CHSCH3 O Cl 95-98 Calc. C 51.3 H 2.7 Found C 50.8 H 2.8 26 CHO(CH2)- O Cl 95-6 Calc. C 53.7 H 3.5 OCH3 Found C 53.8 H 3.5 27 CHO(CH2)2Cl O Cl Oil Calc. C 50.1 H 2.7 Found C 50.0 H 2.8 Table 1 continued... Example No. A B R2 m.pt. C Analysis 28 CO NH Cl 183-5 Calc. C 52.7 H 2.0 N 4.1 Found C 52.5 H 1.9 N 4.0 29 CO N-CH3 Cl 110-2 Calc. C 54.0 H 2.5 N 3.9 Found C 53.7 H 2.3 N 3.9 30 CO N-CH2COOEt Cl 140 Calc. C 53.3 H 3.0 N 3.3 Found C 53.5 H 2.9 N 3.2 31 CO N-CH(CH3)COOEt Cl 114-5 Calc. C 54.4 H 3.4 N 3.2 Found C 54.0 H 3.3 N 3.1 32 CH2 CH2 NO2 125 Calc. C 57.0 H 3.0 N 4.1 Found C 56.8 H 3.1 N 4.1 33 CH-OCH(CH3)- O Cl Oil Calc. C 54.8 H 3.2 COOEt (Isomer I) Found C 54.2 H 3.2 34 CH-OCH2CH2OH O Cl Oil Calc. C 52.5 H 3.1 Found C 52.9 H 3.0 35 CH-N(CH3)2 N-CH3 Cl 82-3 (m.m.s.) 36 CH-CH3 O Cl Oil (m.m.s.) Table 1 continued... Example No. A B R2 m.pt. C Analysis 37 CH-Pyrrolyl O Cl 68-70 Calc. C 57.9 H 2.8 N 3.6 Found C 57.9 H 2.8 N 3.4 38 C(CH3)OCOCH3 O Cl Oil (m.m.s.) 39 C(CH3)OCH3 O Cl Oil (m.m.s.) 40 C(CH3)CH O Cl Oil (m.m.s.) Example 41 Herbicidal Activity To evaluate their herbicidal activity, compounds according to the invention were tested using as representative range of plants: maize, Zea mays (Mz); rice, Oryza sativa (R); barnyard grass, Echinochloa crusgalli (BG); oat, Avena sativa (O); linseed, Linus usitatissimum (L); custard, Sinapsis alba (M); sugar beet, Beta vulgaris (SB) and soya bean, Glycine max (S). The tests fall into two categories, pre-mergence and postemergence. The pre-emergence tests involved spraying a liquid formulation of the compound onto the soil in which the seeds of the plant specied mentioned above had recently been sown. The postemergence tests involved two types of test, viz., soil drench and foliar spray tests. In the soil drench tests the soil in which the seedling plants of the above species were growing was drenched with a liquid formulation containing a compound of the invention, and in the foliar spray tests the seedling plants were sprayed with such a formulation. The soil used in the tests was a prepared horticultural loam. The formulations used in the tests were prepared from solutions of the test compounds in acetone containing 0.4% by weight of an alkylphanol/ethylene oxide condensate available under the trade mark TRITON X-155. These acetone solutions were diluted with water and the resulting formulations applied at dosage levels corresponding to 5 kg or 1 kg of active material per hectare in a volume equivalent to 600 litres per hectare in the soil spray and foliar spray test, and at a dosage of level equivalent to 10 kilograms of active material per hectare in a volume equivalent to approxlmately 3,000 litres per hectare in the soil drench tests. In the pre-emergence tests untreated sown soil and in the post-emergence tests untreated soil bearing seedling plants were used as controls. The herbicidal effects of the test compounds were assessed visually twelve days after spraying the foliage and the soil, and thirteen days after drenching the soil and were recorded on a 0-9 scale. A rating 0 indicates growth as untreated control, a rating 9 indicates death. An increase of 1 unit on the linear scale approximates to a 10% increase in the level of effect. The results of the tests are set out in Table II below, in which the cat'pouas are identified by reference to the preceding examples. Table 2 EMI20.1 Compound <SEP> of <SEP> Soil <SEP> Drench <SEP> Dosage <tb> Example <SEP> No. <SEP> 10 <SEP> kg/ha <SEP> kg/h <SEP> Foliar <SEP> Spray <SEP> Pre-emergence <tb> <SEP> MZ <SEP> R <SEP> BG <SEP> O <SEP> L <SEP> M <SEP> SB <SEP> S <SEP> Mz <SEP> R <SEP> BG <SEP> O <SEP> L <SEP> M <SEP> SB <SEP> S <SEP> Mz <SEP> R <SEP> BG <SEP> O <SEP> L <SEP> M <SEP> SB <SEP> S <tb> <SEP> 1 <SEP> 7 <SEP> 7 <SEP> 9 <SEP> 8 <SEP> 6 <SEP> 6 <SEP> 6 <SEP> 2 <SEP> 5 <SEP> 7 <SEP> 5 <SEP> 9 <SEP> 8 <SEP> 9 <SEP> 9 <SEP> 8 <SEP> 8 <SEP> 5 <SEP> 7 <SEP> 9 <SEP> 8 <SEP> 9 <SEP> 8 <SEP> 9 <SEP> 5 <tb> <SEP> 1 <SEP> 3 <SEP> 4 <SEP> 9 <SEP> 8 <SEP> 9 <SEP> 8 <SEP> 9 <SEP> 8 <SEP> 0 <SEP> 4 <SEP> 9 <SEP> 7 <SEP> 8 <SEP> 7 <SEP> 9 <SEP> 4 <tb> <SEP> 11 <SEP> 7 <SEP> 8 <SEP> 8 <SEP> 4 <SEP> 6 <SEP> 5 <SEP> 4 <SEP> 3 <SEP> 5 <SEP> 4 <SEP> 2 <SEP> 8 <SEP> 3 <SEP> 7 <SEP> 8 <SEP> 5 <SEP> 5 <SEP> 3 <SEP> 5 <SEP> 8 <SEP> 0 <SEP> 5 <SEP> 5 <SEP> 7 <SEP> 0 <tb> <SEP> 1 <SEP> 2 <SEP> 1 <SEP> 5 <SEP> 2 <SEP> 6 <SEP> 6 <SEP> 3 <SEP> 5 <SEP> 0 <SEP> 3 <SEP> 1 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <tb> <SEP> 12 <SEP> 6 <SEP> 7 <SEP> 8 <SEP> 5 <SEP> 7 <SEP> 5 <SEP> 3 <SEP> 4 <SEP> 5 <SEP> 5 <SEP> 4 <SEP> 8 <SEP> 6 <SEP> 8 <SEP> 8 <SEP> 7 <SEP> 8 <SEP> 7 <SEP> 6 <SEP> 9 <SEP> 5 <SEP> 7 <SEP> 5 <SEP> 9 <SEP> 4 <tb> <SEP> 1 <SEP> 2 <SEP> 0 <SEP> 3 <SEP> 3 <SEP> 8 <SEP> 6 <SEP> 5 <SEP> 6 <SEP> 4 <SEP> 4 <SEP> 8 <SEP> 3 <SEP> 5 <SEP> 4 <SEP> 9 <SEP> 0 <tb> <SEP> 2 <SEP> 3 <SEP> 5 <SEP> 5 <SEP> 6 <SEP> 2 <SEP> 3 <SEP> 4 <SEP> 0 <SEP> 5 <SEP> 7 <SEP> 5 <SEP> 9 <SEP> 8 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 7 <SEP> 7 <SEP> 8 <SEP> 6 <SEP> 6 <SEP> 6 <SEP> 8 <SEP> 0 <tb> <SEP> 1 <SEP> 5 <SEP> 4 <SEP> 8 <SEP> 6 <SEP> 8 <SEP> 8 <SEP> 6 <SEP> 7 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 2 <SEP> 0 <tb> <SEP> 3 <SEP> 0 <SEP> 2 <SEP> 6 <SEP> 7 <SEP> 5 <SEP> 4 <SEP> 4 <SEP> 0 <SEP> 5 <SEP> 8 <SEP> 7 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 8 <SEP> 4 <SEP> 4 <SEP> 9 <SEP> 6 <SEP> 6 <SEP> 6 <SEP> 9 <SEP> 0 <tb> <SEP> 1 <SEP> 8 <SEP> 6 <SEP> 8 <SEP> 8 <SEP> 9 <SEP> 8 <SEP> 9 <SEP> 8 <SEP> 2 <SEP> 4 <SEP> 9 <SEP> 5 <SEP> 5 <SEP> 5 <SEP> 9 <SEP> 0 <tb> <SEP> 6 <SEP> 7 <SEP> 6 <SEP> 6 <SEP> 7 <SEP> 7 <SEP> 5 <SEP> 5 <SEP> 1 <SEP> 5 <SEP> 7 <SEP> 7 <SEP> 9 <SEP> 7 <SEP> 9 <SEP> 9 <SEP> 8 <SEP> 8 <SEP> 5 <SEP> 8 <SEP> 8 <SEP> 6 <SEP> 0 <SEP> 6 <SEP> 9 <SEP> 0 <tb> <SEP> 1 <SEP> 5 <SEP> 5 <SEP> 6 <SEP> 4 <SEP> 8 <SEP> 8 <SEP> 5 <SEP> 6 <SEP> 2 <SEP> 3 <SEP> 6 <SEP> 3 <SEP> 0 <SEP> 3 <SEP> 8 <SEP> 0 <tb> <SEP> 14 <SEP> 4 <SEP> 2 <SEP> 4 <SEP> 4 <SEP> 0 <SEP> 7 <SEP> 4 <SEP> 5 <SEP> 5 <SEP> 5 <SEP> 4 <SEP> 7 <SEP> 5 <SEP> 8 <SEP> 8 <SEP> 8 <SEP> 7 <SEP> 2 <SEP> 0 <SEP> 2 <SEP> 0 <SEP> 0 <SEP> 4 <SEP> 4 <SEP> 0 <tb> <SEP> 1 <SEP> 5 <SEP> 3 <SEP> 6 <SEP> 3 <SEP> 6 <SEP> 8 <SEP> 5 <SEP> 6 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <tb> Table 2 continued... EMI21.1 Compound <tb> <SEP> of <SEP> Soil <SEP> Drench <SEP> 10 <SEP> kg/ha <SEP> Dosage <tb> Ex. <SEP> No. <SEP> kg/h <SEP> Foliar <SEP> Spray <SEP> Pre-emergence <tb> <SEP> MZ <SEP> R <SEP> BG <SEP> O <SEP> L <SEP> M <SEP> SB <SEP> S <SEP> Mz <SEP> R <SEP> BG <SEP> O <SEP> L <SEP> M <SEP> SB <SEP> S <SEP> Mz <SEP> R <SEP> BG <SEP> O <SEP> L <SEP> M <SEP> SB <SEP> S <tb> <SEP> 7 <SEP> 7 <SEP> 7 <SEP> 8 <SEP> 7 <SEP> 8 <SEP> 9 <SEP> 9 <SEP> 5 <SEP> 5 <SEP> 9 <SEP> 8 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 8 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <tb> <SEP> 1 <SEP> 8 <SEP> 8 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 7 <SEP> 8 <SEP> 9 <SEP> 8 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <tb> <SEP> 8 <SEP> 5 <SEP> 4 <SEP> 7 <SEP> 6 <SEP> 5 <SEP> 5 <SEP> 5 <SEP> 4 <SEP> 5 <SEP> 8 <SEP> 6 <SEP> 9 <SEP> 8 <SEP> 9 <SEP> 9 <SEP> 8 <SEP> 7 <SEP> 3 <SEP> 0 <SEP> 8 <SEP> 3 <SEP> 4 <SEP> 7 <SEP> 7 <SEP> 0 <tb> <SEP> 1 <SEP> 4 <SEP> 3 <SEP> 8 <SEP> 6 <SEP> 9 <SEP> 8 <SEP> 6 <SEP> 6 <SEP> 2 <SEP> 0 <SEP> 7 <SEP> 2 <SEP> 2 <SEP> 5 <SEP> 6 <SEP> 0 <tb> <SEP> 9 <SEP> 5 <SEP> 4 <SEP> 7 <SEP> 4 <SEP> 3 <SEP> 3 <SEP> 3 <SEP> 2 <SEP> 5 <SEP> 7 <SEP> 2 <SEP> 8 <SEP> 5 <SEP> 7 <SEP> 6 <SEP> 4 <SEP> 5 <SEP> 3 <SEP> 0 <SEP> 6 <SEP> 3 <SEP> 0 <SEP> 4 <SEP> 6 <SEP> 0 <tb> <SEP> 1 <SEP> 3 <SEP> 1 <SEP> 4 <SEP> 3 <SEP> 6 <SEP> 4 <SEP> 2 <SEP> 4 <SEP> 0 <SEP> 0 <SEP> 5 <SEP> 1 <SEP> 0 <SEP> 2 <SEP> 4 <SEP> 0 <tb> <SEP> 10 <SEP> 4 <SEP> 4 <SEP> 7 <SEP> 5 <SEP> 3 <SEP> 3 <SEP> 2 <SEP> 3 <SEP> 5 <SEP> 6 <SEP> 4 <SEP> 8 <SEP> 6 <SEP> 8 <SEP> 8 <SEP> 6 <SEP> 6 <SEP> 0 <SEP> 0 <SEP> 6 <SEP> 0 <SEP> 3 <SEP> 4 <SEP> 5 <SEP> 0 <tb> <SEP> 1 <SEP> 3 <SEP> 2 <SEP> 4 <SEP> 3 <SEP> 5 <SEP> 5 <SEP> 4 <SEP> 4 <SEP> 0 <SEP> 0 <SEP> 5 <SEP> 0 <SEP> 2 <SEP> 2 <SEP> 2 <SEP> 0 <tb> <SEP> 15 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 6 <SEP> 3 <SEP> 8 <SEP> 0 <SEP> 5 <SEP> 6 <SEP> 3 <SEP> 8 <SEP> 6 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 8 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <tb> <SEP> 1 <SEP> 5 <SEP> 2 <SEP> 8 <SEP> 5 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 8 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <tb> <SEP> 16 <SEP> 9 <SEP> 4 <SEP> 9 <SEP> 8 <SEP> 9 <SEP> 7 <SEP> 9 <SEP> 5 <SEP> 5 <SEP> 9 <SEP> 6 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 2 <SEP> 3 <SEP> 9 <SEP> 5 <SEP> 7 <SEP> 7 <SEP> 9 <SEP> 2 <tb> <SEP> 1 <SEP> 8 <SEP> 6 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 0 <SEP> 0 <SEP> 8 <SEP> 4 <SEP> 4 <SEP> 6 <SEP> 8 <SEP> 1 <tb> Table 2 continued... EMI22.1 Compound <tb> <SEP> of <SEP> Soil <SEP> Drench <SEP> 10/kg/ha <SEP> Dosage <tb> Ex. <SEP> No. <SEP> kg/h <SEP> Foliar <SEP> Spray <SEP> Pre-emergence <tb> <SEP> MZ <SEP> R <SEP> BG <SEP> O <SEP> L <SEP> M <SEP> SB <SEP> S <SEP> Mz <SEP> R <SEP> BG <SEP> O <SEP> L <SEP> M <SEP> SB <SEP> S <SEP> Mz <SEP> R <SEP> BG <SEP> O <SEP> L <SEP> M <SEP> SB <SEP> S <tb> 17 <SEP> 4 <SEP> 3 <SEP> 7 <SEP> 7 <SEP> 6 <SEP> 3 <SEP> 6 <SEP> 0 <SEP> 5 <SEP> 8 <SEP> 7 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 4 <SEP> 3 <SEP> 8 <SEP> 6 <SEP> 7 <SEP> 8 <SEP> 9 <SEP> 5 <tb> <SEP> 1 <SEP> 8 <SEP> 6 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 2 <SEP> 3 <SEP> 8 <SEP> 5 <SEP> 6 <SEP> 7 <SEP> 8 <SEP> 2 <tb> 18 <SEP> 6 <SEP> 5 <SEP> 7 <SEP> 7 <SEP> 7 <SEP> 4 <SEP> 9 <SEP> 2 <SEP> 5 <SEP> 8 <SEP> 7 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 0 <SEP> 0 <SEP> 9 <SEP> 5 <SEP> 7 <SEP> 7 <SEP> 8 <SEP> 0 <tb> <SEP> 1 <SEP> 7 <SEP> 6 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 8 <SEP> 0 <SEP> 0 <SEP> 7 <SEP> 3 <SEP> 6 <SEP> 6 <SEP> 5 <SEP> 0 <tb> 19 <SEP> 2 <SEP> 5 <SEP> 7 <SEP> 7 <SEP> 5 <SEP> 5 <SEP> 9 <SEP> 2 <SEP> 5 <SEP> 8 <SEP> 7 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 0 <SEP> 3 <SEP> 8 <SEP> 4 <SEP> 6 <SEP> 7 <SEP> 8 <SEP> 0 <tb> <SEP> 1 <SEP> 6 <SEP> 5 <SEP> 8 <SEP> 8 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 8 <SEP> 0 <SEP> 0 <SEP> 6 <SEP> 1 <SEP> 5 <SEP> 6 <SEP> 7 <SEP> 0 <tb> 20 <SEP> 3 <SEP> 4 <SEP> 5 <SEP> 6 <SEP> 5 <SEP> 4 <SEP> 8 <SEP> 2 <SEP> 5 <SEP> 7 <SEP> 7 <SEP> 9 <SEP> 8 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 7 <SEP> 2 <SEP> 0 <SEP> 7 <SEP> 4 <SEP> 7 <SEP> 7 <SEP> 8 <SEP> 2 <tb> <SEP> 1 <SEP> 6 <SEP> 6 <SEP> 8 <SEP> 8 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 7 <SEP> 0 <SEP> 0 <SEP> 5 <SEP> 1 <SEP> 5 <SEP> 6 <SEP> 6 <SEP> 0 <tb> 21 <SEP> 0 <SEP> 0 <SEP> 2 <SEP> 3 <SEP> 3 <SEP> 2 <SEP> 8 <SEP> 0 <SEP> 5 <SEP> 5 <SEP> 5 <SEP> 6 <SEP> 5 <SEP> 8 <SEP> 9 <SEP> 8 <SEP> 8 <SEP> 3 <SEP> 4 <SEP> 0 <SEP> 0 <SEP> 6 <SEP> 6 <SEP> 8 <SEP> 0 <tb> <SEP> 1 <SEP> 5 <SEP> 5 <SEP> 5 <SEP> 5 <SEP> 8 <SEP> 9 <SEP> 8 <SEP> 8 <SEP> 3 <SEP> 2 <SEP> 0 <SEP> 0 <SEP> 6 <SEP> 6 <SEP> 6 <SEP> 0 <tb> 22 <SEP> 6 <SEP> 6 <SEP> 7 <SEP> 5 <SEP> 4 <SEP> 3 <SEP> 4 <SEP> 2 <SEP> 5 <SEP> 6 <SEP> 4 <SEP> 8 <SEP> 5 <SEP> 7 <SEP> 5 <SEP> 5 <SEP> 7 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <tb> <SEP> 1 <SEP> 4 <SEP> 2 <SEP> 4 <SEP> 3 <SEP> 5 <SEP> 4 <SEP> 4 <SEP> 4 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <tb> Table 2 Continued... EMI23.1 Compound <tb> <SEP> of <SEP> Soil <SEP> Drench <SEP> 10 <SEP> kg/ha <SEP> Dosage <tb> Ex. <SEP> No. <SEP> kg/h <SEP> Foliar <SEP> Spray <SEP> Pre-emergence <tb> <SEP> MZ <SEP> R <SEP> BG <SEP> O <SEP> L <SEP> M <SEP> SB <SEP> S <SEP> Mz <SEP> R <SEP> BG <SEP> O <SEP> L <SEP> M <SEP> SB <SEP> S <SEP> Mz <SEP> R <SEP> BG <SEP> O <SEP> L <SEP> M <SEP> SB <SEP> S <tb> 23 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 5 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 3 <SEP> 0 <SEP> 8 <SEP> 7 <SEP> 5 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <tb> <SEP> 1 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 3 <SEP> 0 <SEP> 8 <SEP> 7 <SEP> 5 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <tb> 25 <SEP> 0 <SEP> 5 <SEP> 4 <SEP> 6 <SEP> 5 <SEP> 4 <SEP> 9 <SEP> 0 <SEP> 5 <SEP> 7 <SEP> 6 <SEP> 8 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 8 <SEP> 0 <SEP> 0 <SEP> 4 <SEP> 0 <SEP> 0 <SEP> 6 <SEP> 7 <SEP> 0 <tb> <SEP> 1 <SEP> 4 <SEP> 4 <SEP> 6 <SEP> 7 <SEP> 9 <SEP> 8 <SEP> 9 <SEP> 8 <SEP> 0 <SEP> 0 <SEP> 2 <SEP> 0 <SEP> 0 <SEP> 4 <SEP> 7 <SEP> 0 <tb> 26 <SEP> 7 <SEP> 7 <SEP> 7 <SEP> 8 <SEP> 4 <SEP> 3 <SEP> 6 <SEP> 6 <SEP> 5 <SEP> 5 <SEP> 5 <SEP> 6 <SEP> 7 <SEP> 8 <SEP> 7 <SEP> 9 <SEP> 8 <SEP> 0 <SEP> 0 <SEP> 8 <SEP> 2 <SEP> 0 <SEP> 6 <SEP> 7 <SEP> 5 <tb> <SEP> 1 <SEP> 5 <SEP> 4 <SEP> 6 <SEP> 7 <SEP> 8 <SEP> 7 <SEP> 8 <SEP> 6 <SEP> 0 <SEP> 0 <SEP> 5 <SEP> 1 <SEP> 0 <SEP> 3 <SEP> 7 <SEP> 0 <tb> 27 <SEP> 0 <SEP> 4 <SEP> 3 <SEP> 6 <SEP> 6 <SEP> 7 <SEP> 8 <SEP> 5 <SEP> 5 <SEP> 6 <SEP> 4 <SEP> 8 <SEP> 8 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 6 <SEP> 0 <SEP> 0 <SEP> 5 <SEP> 2 <SEP> 7 <SEP> 3 <SEP> 7 <SEP> 4 <tb> <SEP> 1 <SEP> 6 <SEP> 3 <SEP> 6 <SEP> 5 <SEP> 8 <SEP> 7 <SEP> 7 <SEP> 9 <SEP> 6 <SEP> 0 <SEP> 3 <SEP> 1 <SEP> 4 <SEP> 3 <SEP> 7 <SEP> 0 <tb> 37 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 5 <SEP> 4 <SEP> 4 <SEP> 6 <SEP> 3 <SEP> 8 <SEP> 8 <SEP> 8 <SEP> 7 <SEP> 4 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 6 <SEP> 7 <SEP> 7 <tb> <SEP> 1 <SEP> 1 <SEP> 1 <SEP> 1 <SEP> 1 <SEP> 6 <SEP> 7 <SEP> 7 <SEP> 4 <SEP> 1 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <tb> 34 <SEP> 6 <SEP> 7 <SEP> 7 <SEP> 8 <SEP> 6 <SEP> 0 <SEP> 4 <SEP> 5 <SEP> 5 <SEP> 8 <SEP> 6 <SEP> 8 <SEP> 7 <SEP> 9 <SEP> 8 <SEP> 7 <SEP> 8 <SEP> 4 <SEP> 4 <SEP> 8 <SEP> 3 <SEP> 8 <SEP> 8 <SEP> 9 <SEP> 4 <tb> <SEP> 1 <SEP> 3 <SEP> 3 <SEP> 5 <SEP> 4 <SEP> 9 <SEP> 6 <SEP> 5 <SEP> 6 <SEP> 0 <SEP> 3 <SEP> 2 <SEP> 0 <SEP> 6 <SEP> 4 <SEP> 5 <SEP> 0 <tb> Table 2 Continued... EMI24.1 Compound <tb> <SEP> of <SEP> Soil <SEP> Drench <SEP> 10 <SEP> kg/ha <SEP> Dosage <tb> Ex. <SEP> No. <SEP> kg/h <SEP> Foliar <SEP> Spray <SEP> Pre-emergence <tb> <SEP> MZ <SEP> R <SEP> BG <SEP> O <SEP> L <SEP> M <SEP> SB <SEP> S <SEP> Mz <SEP> R <SEP> BG <SEP> O <SEP> L <SEP> M <SEP> SB <SEP> S <SEP> Mz <SEP> R <SEP> BG <SEP> O <SEP> L <SEP> M <SEP> SB <SEP> S <tb> 35 <SEP> 5 <tb> <SEP> 1 <SEP> 4 <SEP> 4 <SEP> 4 <SEP> 3 <SEP> 6 <SEP> 5 <SEP> 5 <SEP> 4 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <tb> 36 <SEP> 9 <SEP> 8 <SEP> 9 <SEP> 8 <SEP> 9 <SEP> 7 <SEP> 7 <SEP> 5 <SEP> 5 <SEP> 8 <SEP> 8 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 7 <SEP> 8 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 8 <SEP> 9 <SEP> 5 <tb> <SEP> 1 <SEP> 5 <SEP> 7 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 2 <SEP> 7 <SEP> 9 <SEP> 8 <SEP> 8 <SEP> 8 <SEP> 9 <SEP> 2 <tb> 28 <SEP> 0 <SEP> 0 <SEP> 2 <SEP> 0 <SEP> 0 <SEP> 3 <SEP> 3 <SEP> 4 <SEP> 5 <SEP> 5 <SEP> 5 <SEP> 6 <SEP> 4 <SEP> 5 <SEP> 5 <SEP> 6 <SEP> 4 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 5 <SEP> 0 <tb> <SEP> 1 <SEP> 5 <SEP> 5 <SEP> 4 <SEP> 3 <SEP> 4 <SEP> 4 <SEP> 4 <SEP> 3 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 5 <SEP> 0 <tb> 30 <SEP> 0 <SEP> 0 <SEP> 3 <SEP> 2 <SEP> 0 <SEP> 0 <SEP> 3 <SEP> 0 <SEP> 5 <SEP> 6 <SEP> 4 <SEP> 6 <SEP> 5 <SEP> 8 <SEP> 6 <SEP> 7 <SEP> 5 <SEP> 0 <SEP> 0 <SEP> 6 <SEP> 0 <SEP> 4 <SEP> 3 <SEP> 5 <SEP> 2 <tb> <SEP> 1 <SEP> 4 <SEP> 2 <SEP> 4 <SEP> 4 <SEP> 8 <SEP> 5 <SEP> 5 <SEP> 3 <SEP> 0 <SEP> 0 <SEP> 3 <SEP> 0 <SEP> 2 <SEP> 1 <SEP> 5 <SEP> 1 <tb> 29 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 5 <SEP> 4 <SEP> 3 <SEP> 5 <SEP> 5 <SEP> 8 <SEP> 5 <SEP> 7 <SEP> 6 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <tb> <SEP> 1 <SEP> 2 <SEP> 1 <SEP> 2 <SEP> 4 <SEP> 5 <SEP> 4 <SEP> 4 <SEP> 5 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <tb> 32 <SEP> 3 <SEP> 2 <SEP> 7 <SEP> 4 <SEP> 2 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 5 <SEP> 7 <SEP> 3 <SEP> 7 <SEP> 6 <SEP> 7 <SEP> 3 <SEP> 4 <SEP> 6 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <tb> <SEP> 1 <SEP> 2 <SEP> 2 <SEP> 6 <SEP> 4 <SEP> 4 <SEP> 2 <SEP> 3 <SEP> 4 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <SEP> 0 <tb> Table 2 continued... EMI25.1 Compound <tb> <SEP> of <SEP> Soil <SEP> Drench <SEP> 10 <SEP> kg/ha <SEP> Dosage <tb> Ex. <SEP> No. <SEP> kg/h <SEP> Foliar <SEP> Spray <SEP> Pre-emergence <tb> <SEP> MZ <SEP> R <SEP> BG <SEP> O <SEP> L <SEP> M <SEP> SB <SEP> S <SEP> Mz <SEP> R <SEP> BG <SEP> O <SEP> L <SEP> M <SEP> SB <SEP> S <SEP> Mz <SEP> R <SEP> BG <SEP> O <SEP> L <SEP> M <SEP> SB <SEP> S <tb> 38 <SEP> 7 <SEP> 9 <SEP> 8 <SEP> 9 <SEP> 8 <SEP> 8 <SEP> 9 <SEP> 4 <SEP> 5 <SEP> 7 <SEP> 8 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 8 <SEP> 7 <SEP> 2 <SEP> 8 <SEP> 9 <SEP> 9 <SEP> 8 <SEP> 5 <SEP> 9 <SEP> 7 <tb> <SEP> 1 <SEP> 3 <SEP> 8 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 8 <SEP> 6 <SEP> 6 <SEP> 0 <SEP> 6 <SEP> 8 <SEP> 8 <SEP> 6 <SEP> 4 <SEP> 8 <SEP> 0 <tb> 39 <SEP> 7 <SEP> 7 <SEP> 8 <SEP> 8 <SEP> 9 <SEP> 8 <SEP> 9 <SEP> 7 <SEP> 5 <SEP> 8 <SEP> 6 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 8 <SEP> 8 <SEP> 9 <SEP> 8 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 8 <tb> <SEP> 1 <SEP> 6 <SEP> 4 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 6 <SEP> 7 <SEP> 9 <SEP> 7 <SEP> 9 <SEP> 9 <SEP> 9 <SEP> 8 <tb>

Claims: CLAIMS 1. A herbicidal composition which comprises a carrier and, as active ingredient, a diphenyl ether derivative having the general formula I: EMI26.1 wherein R1 represents a hydrogen or halogen atom or an alkyl or haloalkyl group. N and h , which may be the sane or different, each independently represents a hydrogen or halogen atan or an alkyl, haloalkyl, nitro or cyano group. A and B, which may be the same or different, each independently represents a divalent group selected from EMI26.2 provided that when A different from A and cannot each R4, which may be the same of different, represents a hydrogen or halogen atom or an optionally substituted alkyl, cycloalkyl, alkenyl, alkynyl, aryl, aralkyl, alkaryl, alkoxy, cycloalkoxy, alkenyloxy, alkynyloxy, alkoxycarbonylalkoxy, alkylthio, acyl, acylexy, carboxyl, alkoxycarbonyl or heterocyclic group, an amino group of formula NR6R7, or when one R4 represents a hydrogen atom, an alkoxy group or a hydrocarbon group, then the other may represent a hydroxyl group, or both groups R4 together may represent an imino group ot formula z I represents a hydrogen atan, a carboxyl or hydroxyl group, or an optionally substituted alkyl, alkoxy, aralkyl, alkoxycarbonyl or alkoxycarbonylalkyl group, or an amino group of formula NR6R7; ; R6 R6 and b , which may be the saite or different, each represents a hydrogen atan or an optionally substituted alkyl, aryl or acyl group; and X, both in formula I and in the definitions of the substituents therein, represents an oxygen or sulphur atom. 2. Compositions as claimed in claim 1 wherein the active ingredient is a carbon of general formula I wherein X represents an oxygen atom; A represents an oxygen atom, a carbonyl group, the group C(R4)2 wherein one group R4 is a hydrogen atom, an alkyl or alkoxy group of up to 4 carbon atoms, or an aryl group, and the other group R4 is a hydrogen or halogen atom, a hydroxyl group, an alkyl group of up to 4 carbon atans, an alkoxy group of up to 4 carbon atoms, optionally substituted by a halogen atan, or a hydroxyl or alkoxy group, a cycloalkoxy group of 5 to 8 carbon atoms, an alkenyloxy or alkynyloxy group of up to 6 carbon atoms, an alkoxycarbonylalkoxy group, an alkylthio group of up to 4 carbon atoms, an alkyl group, a pyridyl group, or an amino group of formula NR6R7 wherein R6 represents a hydrogen atan or an alkyl group of up to 4 carbon atoms and R7 represents an alkyl group of up to 4 carbon atans, a phenyl group optionally substituted by at least one halogen atom, or an alkylcarbonyl, alkylcarbamoyl or alkylsulphonyl group; and B represents an oxygen atom, the group C(R4)2 wherein each group R4, which may be the same or different, independently represents a hydrogen atan or an alkyl or alkoxy group of up to 4 carbon atoms, or the group NR5 wherein R5 represents a hydrogen atom, an alkyl group of up to 4 carbon atoms, a benzyl group, or an alkoxycarbonylalkyl group of up to 8 carbon atoms. 3@ Cbmpositions as claimed in claim 2 wherein B represents an oxygen atam and A represents the group C(R4)2 in which R4 is as defined in claim 2. 4. Canpositions as claimed in claims 1, 2 or 3 wherein R1 represents a trifluorarethyl group, R2 represents a halogen atom, and R3 represents a hydrogen atom. 5. A composition as claimed in any one of the preceding claims which comprises at lest two carriers, at least one of which is a surface-active agent. 6. A diphanyl ether derivative of the formula I as shown in claim 1, wherein the substituents have the meanings defined in claim 1, with the exception of 4-(2-chlorc-4- trifluoromethylphenoxy) phthalic anhydride. 7. A diphenyl ether as claimed in claim 6 wherein the substituents of formula I have the rtanings defined in any one of claims 2-4. 8. A process for the preparation of a diphenyl ether as claimed in claim 6, which comprises reacting a phthalide of formula EMI28.1 with a compound of the formula: EMI28.2 wherein A, B, E R, and RI have the meanings defined in claim 6; and of Z and Q represents a halogen atom or nitro group and the other represents a group of formula -CM wherein M represents a hydrogen or alkali metal atan, followed, when the thiophthalide is required, by reaction with phosphorus pentasulphide, or when the desired compound is a halo or hydroxy methylene group by reaction with a halogenating agent and, tor the hydroxymethylene derivative, hydrolysis of the resultant halatethylene derivative. 9. Process as claimed in claim 8. wherein the initial reaction is carried out by reacting a compound of formula II wherein Q is hydroxy with an alkali metal hydroxide in an alkanol solvent, followed by reaction of the resultant alkoxide with a carpund of formula III wherein Z represents a chlorine atom. 10. Process as claimed in claim 9 wherein the reaction of the alkoxide with the chloro compound III is carried out in an organic solvent at elevated temperature and under an inert atmosphere. 11. Method of combating undesired plant growth at a locus, which comprises treating the locus with a ccwposition as claimed in any one of claims 1-5 or a compound as claimed in claim 6 or 7. 12. Use as a herbicide of a diphenyl ether as defined in any one of claims 1-7.

Inventors: CLARK, MICHAEL THOMAS, GILMORE, IAN JAMES, HADDOCK, ERNEST
Applicants: SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ B.V.
Application year: 1984
Main classification: C07D307
IPC codes: C07D209, C07C69, C07C205, A01N37, A01P13, C07C49, C07C325, A01N47, C07C65, A01N43, C07D307, A01N35, C07C67, C07C62