Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D231/00—Heterocyclic compounds containing 1,2-diazole or hydrogenated 1,2-diazole rings
  • C07D231/02—Heterocyclic compounds containing 1,2-diazole or hydrogenated 1,2-diazole rings not condensed with other rings
  • C07D231/10—Heterocyclic compounds containing 1,2-diazole or hydrogenated 1,2-diazole rings not condensed with other rings having two or three double bonds between ring members or between ring members and non-ring members
  • C07D231/14—Heterocyclic compounds containing 1,2-diazole or hydrogenated 1,2-diazole rings not condensed with other rings having two or three double bonds between ring members or between ring members and non-ring members with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
  • C07D231/18—One oxygen or sulfur atom
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D401/00—Heterocyclic compounds containing two or more hetero rings, having nitrogen atoms as the only ring hetero atoms, at least one ring being a six-membered ring with only one nitrogen atom
  • C07D401/02—Heterocyclic compounds containing two or more hetero rings, having nitrogen atoms as the only ring hetero atoms, at least one ring being a six-membered ring with only one nitrogen atom containing two hetero rings
  • C07D401/12—Heterocyclic compounds containing two or more hetero rings, having nitrogen atoms as the only ring hetero atoms, at least one ring being a six-membered ring with only one nitrogen atom containing two hetero rings linked by a chain containing hetero atoms as chain links
• • A—HUMAN NECESSITIES
  • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
  • A01N—PRESERVATION OF BODIES OF HUMANS OR ANIMALS OR PLANTS OR PARTS THEREOF; BIOCIDES, e.g. AS DISINFECTANTS, AS PESTICIDES OR AS HERBICIDES; PEST REPELLANTS OR ATTRACTANTS; PLANT GROWTH REGULATORS
  • A01N43/00—Biocides, pest repellants or attractants, or plant growth regulators containing heterocyclic compounds
  • A01N43/48—Biocides, pest repellants or attractants, or plant growth regulators containing heterocyclic compounds having rings with two nitrogen atoms as the only ring hetero atoms
  • A01N43/56—1,2-Diazoles; Hydrogenated 1,2-diazoles
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D231/00—Heterocyclic compounds containing 1,2-diazole or hydrogenated 1,2-diazole rings
  • C07D231/02—Heterocyclic compounds containing 1,2-diazole or hydrogenated 1,2-diazole rings not condensed with other rings
  • C07D231/10—Heterocyclic compounds containing 1,2-diazole or hydrogenated 1,2-diazole rings not condensed with other rings having two or three double bonds between ring members or between ring members and non-ring members
  • C07D231/14—Heterocyclic compounds containing 1,2-diazole or hydrogenated 1,2-diazole rings not condensed with other rings having two or three double bonds between ring members or between ring members and non-ring members with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
  • C07D231/18—One oxygen or sulfur atom
  • C07D231/20—One oxygen atom attached in position 3 or 5
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D231/00—Heterocyclic compounds containing 1,2-diazole or hydrogenated 1,2-diazole rings
  • C07D231/02—Heterocyclic compounds containing 1,2-diazole or hydrogenated 1,2-diazole rings not condensed with other rings
  • C07D231/10—Heterocyclic compounds containing 1,2-diazole or hydrogenated 1,2-diazole rings not condensed with other rings having two or three double bonds between ring members or between ring members and non-ring members
  • C07D231/14—Heterocyclic compounds containing 1,2-diazole or hydrogenated 1,2-diazole rings not condensed with other rings having two or three double bonds between ring members or between ring members and non-ring members with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
  • C07D231/18—One oxygen or sulfur atom
  • C07D231/20—One oxygen atom attached in position 3 or 5
  • C07D231/22—One oxygen atom attached in position 3 or 5 with aryl radicals attached to ring nitrogen atoms
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D231/00—Heterocyclic compounds containing 1,2-diazole or hydrogenated 1,2-diazole rings
  • C07D231/02—Heterocyclic compounds containing 1,2-diazole or hydrogenated 1,2-diazole rings not condensed with other rings
  • C07D231/10—Heterocyclic compounds containing 1,2-diazole or hydrogenated 1,2-diazole rings not condensed with other rings having two or three double bonds between ring members or between ring members and non-ring members
  • C07D231/14—Heterocyclic compounds containing 1,2-diazole or hydrogenated 1,2-diazole rings not condensed with other rings having two or three double bonds between ring members or between ring members and non-ring members with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
  • C07D231/28—Two oxygen or sulfur atoms
  • C07D231/30—Two oxygen or sulfur atoms attached in positions 3 and 5
  • C07D231/32—Oxygen atoms
  • C07D231/36—Oxygen atoms with hydrocarbon radicals, substituted by hetero atoms, attached in position 4

Definitions

• This invention relates to N-substituted pyrazole derivatives, processes for their preparation, compositions containing them and their use as herbicides.
• the present invention provides N-substituted pyrazole derivatives of formula I:
• R 1 represents:- a straight or branched chain alkyl group containing up to 6 carbon atoms optionally substituted by one or more halogen atoms;
• n represents zero or one and Ar represents a phenyl group optionally substituted by one or more groups selected from halogen, nitro, R 6 , -OH, -OR 6 ,
• R2 represents :- a group -X-R 10 ;
• R 3 represents:- a hydrogen or halogen atom
• phenyl optionally substituted by one or more groups selected from halogen, nitro, R 6 , -OR 6 and cyano; or
• R 4 represents:
• phenyl optionally substituted by one or more groups selected from halogen, nitro, R 6 , -OR 6 , -S(O) m R 7 and -NR 8 R 9 ; or pyridyl optionally substituted by one or more groups selected from halogen, nitro, R 6 , -OR 6 , -S(O) m R 7 and -NR 8 R 9 ;
• R 5 represents the hydrogen atom or a straight- or branched-chain alkyl group containing up to 6 carbon atoms
• Y represents the oxygen or sulphur atom
• R 6 represents a straight- or branched- chain alkyl group containing up to 6 carbon atoms optionally substituted by one or more halogen atoms;
• R 61 and R 62 which may be the same or different, each represents a straight- or branched- chain alkyl group containing up to 6 carbon atoms optionally substituted by one or more halogen atoms;
• R7 represents a straight- or branched- chain alkyl group containing up to 4 carbon atoms optionally substituted by one or more halogen atoms;
• R 71 represents:- a straight- or branched- chain alkyl group containing up to 6 carbon atoms optionally substituted by one or more halogen atoms; or
• phenyl optionally substituted by one or more groups selected from halogen, nitro, R 6 , -OR 6 , -S(O) m R 7 and -NR 8 R 9 ;
• R 8 and R 9 which may be the same or different, each represents hydrogen or a straight or branched chain alkyl group containing up to 6 carbon atoms optionally substituted by one or more halogen atoms;
• R 10 represents:- phenyl optionally substituted by one or more groups selected from halogen, nitro, R 6 , -OR 8 -S(O) m R 7 , -NHCOR 6 and
• pyridyl optionally substituted by one or more groups selected from halogen, nitro, R 6 , -OR 6 , -S(O) m R 7 , -NHCOR 6 and -NR 8 R 9 ;
• groups optionally substituted by one or more groups selected from halogen, -OR 8 , -S(O) q R 6 , -NR 8 R 9 , -CO 2 R 8 -OCOR 6 , -NHCOR 6 , -CONR 8 R 9 R 12 -COR 8 R 13 and cyano;
• X represents an oxygen atom, -NRH- or -S(O)p-,
• R 11 represents hydrogen or a straight or branched chain alkyl group containing up to 6 carbon atoms optionally substituted by one or more halogen atoms;
• R 12 represents a cycloalkyl group containing from three to seven ring atoms, which may optionally contain from one to three heteroatoms in the ring selected from oxygen, sulphur and -NR 5 -;
• R 13 represents:
• agriculturally acceptable salts salts the cations of which are known and accepted in the art for the formation of salts for agricultural or horticultural use.
• the salts are water-soluble.
• Suitable salts with bases include alkali metal (eg. sodium and potassium), alkaline earth metal (eg. calcium and magnesium), ammonium and amine (eg. diethanolamine, triethanolamine, octylamine, morpholine and dioctylmethylamine) salts.
• Suitable acid addition salts formed by compounds of formula I containing an amino group, include salts with inorganic acids, for example hydrochlorides, sulphates, phosphates and nitrates and salts with organic acids, for example acetic acid.
• R 4 represents a group selected from
• R 1 represents:- a straight or branched chain alkyl group containing up to 6 carbon atoms optionally substituted by one or more halogen atoms; a cycloalkyl group containing from 3 to 6 carbon atoms optionally substituted by one or more groups R 6 ; or
• n represents zero or one and Ar represents phenyl optionally substituted by one or more groups selected from halogen, nitro, R 6 , -OH, -OR 6 , -S(O) m R 7 and
• R 3 represents:- a hydrogen or halogen atom
• phenyl optionally substituted by one or more groups selected from halogen, nitro, R 6 , -OR 6 and cyano; or
• R 10 represents:- phenyl optionally substituted by one or more groups selected from halogen, nitro, R 6 , -OR 8 , -S(O) m R 7 , -NHCOR 6 and -NR 8 R 9 ; or
• pyridyl optionally substituted by one or more groups selected from halogen, nitro, R 6 -OR 6 , -S(O) m R 7 , -NHCOR 6 and -NR 8 R 9 .
• X preferably represents an oxygen or sulphur atom or a group -NRH.
• X preferably represents an oxygen or sulphur atom or a group -NRH.
• the invention provides N-substituted pyrazole derivatives of formula I in which:
• R 1 represents:- a straight or branched chain alkyl group containing up to 6 carbon atoms optionally substituted by one or more halogen atoms;
• R 3 represents:- a hydrogen or halogen atom
• phenyl optionally substituted by one or more groups selected from halogen, nitro, R 6 , -OR 6 and cyano; or
• R 10 represents:- straight- or branched- chain alkyl, alkenyl or alkynyl group containing up to ten carbon atoms wherein the chain may optionally comprise one or more oxygen or sulphur atoms or -NR5- groups, optionally substituted by one or more groups selected from halogen, -OR 8 , -S(O) q R 6 -NR 8 R 9 , -CO 2 R 8 , -OCOR 6 -NHCOR 6 ,
• R 3 represents:- a hydrogen or halogen atom
• phenyl optionally substituted by one or more groups selected from halogen, nitro, R 6 , -OR 6 and cyano; or
• R 10 represents a straight- or branched- chain alkyl, alkenyl or alkynyl group containing up to ten carbon atoms wherein the chain may optionally comprise one or more oxygen or sulphur atoms or
• -NR 5 - groups optionally substituted by one or mpre groups selected from halogen, -OR 8 , -S(O) q R 6 , -NR 8 R 9 , -CO 2 R 8 , -OCOR 6 , -NHCOR 6 , -CONR 8 R 9 , R 12 , -COR 8 , R 13 and cyano.
• a preferred class of compounds of formula I are those wherein
• Y represents an oxygen atom
• a further preferred class of compounds of formula I are those wherein R 1 represents methyl or ethyl.
• a further preferred class of compounds of formula I are those wherein R 1 represents methyl.
• R 4 represents 2,4-difluorophenyl
• a further preferred class of compounds of formula I are those wherein X represents a sulphur atom.
• Compounds of formula I wherein X represents an oxygen atom are also preferred.
• a further preferred class of compounds of formula I are those wherein R 10 represents phenyl substituted by at least one halogen atom, preferably fluorine.
• a further preferred class of compounds of formula I are those wherein R 10 represents a straight- or branched- chain alkyl or alkenyl group containing up to four carbon atoms optionally substituted by one or more halogen atoms.
• a further preferred class of compounds of formula I are those in which R 2 represents -SR 10 , wherein R 10 represents an alkenyl group containing up to four carbon atoms.
• a further preferred class of compounds of formula I are those wherein R 10 represents a straight- or branched- chain alkyl, alkenyl or alkynyl group containing up to six, preferably up to five carbon atoms optionally substituted by one or more halogen atoms.
• R 10 represents a straight- or branched- chain alkyl group which is substituted by one or more groups R 12 or R 13 , preferably R 10 represents a group -CH 2 R 1 2 or -CH 2 R 13 .
• a further preferred class of compounds of formula I are those wherein:
• R 1 represents an alkyl group containing one or two carbon atoms optionally substituted by one or more halogen (preferably fluorine) atoms which may be the same or different;
• R 3 represents:
• R 4 represents phenyl optionally substituted by from one to three groups selected from halogen, trifluoromethyl and methoxy;
• R 5 represents the hydrogen atom or a methyl group
• Y represents an oxygen or sulphur atom
• X represents an oxygen atom or a group -S(O)p-;
• R 10 represents:
• phenyl or pyridyl optionally substituted by a group selected from halogen, methoxy, hydroxy, -NHCOMe, -NH 2 , -SMe, methyl and trifluoromethyl;
• Particularly important compounds because of their herbicidal properties, include the following:
• the compounds of formula I can be prepared by the application or adaptation of known methods (i.e. methods heretofore used or described in the chemical literature), for example as hereinafter described.
• compounds of formula I may be prepared by reacting a compound of formula II:
• R 1 , R 3 , R 4 , R 5 and Y are as hereinbefore defined and Z represents a leaving group, with a compound of formula III :
• R 2 is as hereinbefore defined and X 1 represents hydrogen or an alkali metal (e.g. sodium or potassium).
• X 1 represents hydrogen or an alkali metal (e.g. sodium or potassium).
• the reaction is generally performed in an inert solvent such as acetonitrile, dioxan or tetrahydrofuran optionally in the presence of a base, e.g. sodium hydride, potassium t-butoxide or preferably potassium carbonate, at a temperature from ambient to the reflux temperature of the solvent.
• a base e.g. sodium hydride, potassium t-butoxide or preferably potassium carbonate
• the leaving group Z is a halogen atom e.g. chlorine bromine or fluorine
• compounds of formula I wherein Y represents the sulphur atom may be prepared by reacting the corresponding compound of formula I in which Y represents the oxygen atom with a thionating compound, for example Lawesson's reagent [2,4-bis(4-methoxyphenyl)-1,3-dithia-2,4-diphosphetane-2,4-disulphide] in an inert solvent, preferably toluene at a temperature from 50°C to the reflux temperature of the solvent.
• a thionating compound for example Lawesson's reagent [2,4-bis(4-methoxyphenyl)-1,3-dithia-2,4-diphosphetane-2,4-disulphide]
• an inert solvent preferably toluene at a temperature from 50°C to the reflux temperature of the solvent.
• compounds of formula I wherein R 5 represents a straight- or branched- chain alkyl group containing up to 6 carbon atoms may be prepared by reacting the corresponding compound of formula I in which R 5 represents hydrogen with an alkylating agent, preferably an alkyl halide or a dialkylsulphate, in the presence of a base, for example potassium hydroxide or potassium carbonate, in an inert solvent such as tetrahydrofuran at a temperature from ambient to the reflux temperature of the solvent.
• a phase transfer catalyst such as tetrabutylammonium bromide typically as 0.01-0.1 mole%.
• the sodium or potassium salt of compound I may be prepared by reacting a compound of formula I wherein R 5 represents hydrogen with a base preferably sodium hydride in an inert solvent followed by reaction with an alkylating agent.
• R 1 , R 2 and R 3 are as hereinbefore defined, with a halogenating agent to give an acid halide (which may optionally be isolated) followed by reaction with an amine of formula N
• the halogenating agent is a chlorinating agent, for example thionyl chloride and the reaction to give the acid halide is optionally performed in an inert solvent at a temperature from ambient to the reflux temperature.
• the reaction between the acid halide and the amine of formula V is generally performed in the presence of base, preferably triethylamine, in an inert solvent e.g. tetrahydrofuran at a temperature from 0°C to the reflux temperature of the solvent.
• compounds of formula I may also be prepared by the reaction of a compound of formula IVa or a salt thereof:
• R 1 , R 3 , R 4 , R 5 , Y and X are as hereinbefore defined with a compound of formula R 10 -L wherein R 10 is as hereinbefore defined and L is a leaving group.
• L represents a halogen atom (more preferably chlorine or bromine),
• reaction is generally performed in an inert solvent such as ethanol or methanol in the presence of a base (e.g. sodium hydride or sodium methoxide).
• a base e.g. sodium hydride or sodium methoxide
• a salt of a compound of formula (IVa) preferably the alkaline metal or alkaline earth metal salt is used (e.g. the sodium or potassium salt).
• compounds containing a group -XR 10 in which R 10 represents phenyl or pyridyl substituted by a group -SR 7 may be prepared by the diazotisation of the corresponding compounds in which R 10 represents phenyl or pyridyl substituted by -NH 2 followed by the reaction of the diazotised product thus obtained with a disulphide of formula R 7 S-SR 7 wherein R 7 is as hereinbefore defined.
• the reaction is generally performed using an a diazotising reagent such as an alkyl nitrite (e.g. t-butyl nitrite in an inert solvent (e.g.
• Z represents a leaving group, e.g. halogen, via conversion to the acid halide, preferably the acid chloride, for example by reacting with thionyl chloride optionally in the presence of an inert solvent at a temperature from ambient to the reflux temperature, and subsequent reaction of the acid chloride (which may optionally be isolated) with an amine of formula V in the presence of a base, preferably triethylamine in an inert solvent, eg tetrahydrofuran, at a temperature from 0°C to the reflux
• a base preferably triethylamine in an inert solvent, eg tetrahydrofuran
• Compounds of formula II wherein Y represents the sulphur atom may be prepared by reacting the corresponding compound of formula II in which Y represents the oxygen atom with a thionating compound, for example Lawesson's reagent [2,4-bis(4-methoxyphenyl)-1,3-dithia-2,4-diphosphetane-2,4-disulphide] in an inert solvent, preferably toluene at a temperature from 50°C to the reflux temperature of the solvent.
• a thionating compound for example Lawesson's reagent [2,4-bis(4-methoxyphenyl)-1,3-dithia-2,4-diphosphetane-2,4-disulphide]
• an inert solvent preferably toluene at a temperature from 50°C to the reflux temperature of the solvent.
• ⁇ 1 represents an alkali metal e.g. sodium or potassium
• X 1 represents hydrogen
• an alkali metal-containing base such as NaH
• an inert solvent such as dioxan
• R represents an alkyl group. This may be achieved by conventional techniques, for example by reaction with potassium carbonate in a ethanolic solvent.
• Compounds of formula IV may also be prepared by the reaction of an acid of formula (VI) with a compound of formula (III). The reaction is generally performed as described above for the reaction of a compound of formula (II) with a compound of formula (III).
• Compounds of formula VI may be prepared by the oxidation of the corresponding aldehyde of formula VII using an oxidant, preferably potassium permanganate in the presence of a base, preferably sodium hydroxide, in a solvent, preferably water at a temperature from ambient to 100°C.
• an oxidant preferably potassium permanganate in the presence of a base, preferably sodium hydroxide, in a solvent, preferably water at a temperature from ambient to 100°C.
• the formylating agent is a mixture of phosphorus oxychloride and N,N-dimethylformamide, when a simultaneous chlorination is effected to produce a compound of formula VII in which Z represents chlorine.
• the reaction is generally carried out at a temperature from 0°C to 150oC.
• 5-Hydroxypyrazoles of formula VIII may be prepared by the reaction of a beta-ketoester of formula IX:
• A represents lower alkyl, with a hydrazine of formula X:
• reaction is generally performed in a solvent, preferably water, at a temperature from ambient to the reflux temperature.
• a solvent preferably water
• a mixture of isomeric products may be produced during this reaction which may be separated by methods well known in the art.
• the preparation of the above intermediates VI, VII and VIII are well described in the literature, for example J.Het.Chem 27, 243 (1990) L.F.Lee et al.
• R 3 represents cyano
• Compounds of formula VIII wherein R 3 represents cyano may be prepared by dehydration of the corresponding compound of formula VHI in which R 3 is replaced by -CONH 2 using for example phosphorus oxychloride optionally in the presence of an inert solvent at a temperature from ambient to the reflux temperature or para-toluenesulphonyl chloride in pyridine at a temperature from
• Compounds of formula VIIl in which R 3 is replaced by -CONH2 may be prepared by hydrolysis of the corresponding ester of formula VIII, wherein R 3 represents -CO 2 R 6 , preferably using a solution of sodium or potassium hydroxide in a solvent, e.g. aqueous alcohol at a temperature from 0°C to the reflux temperature of the solvent, to give the corresponding carboxylic acid which is converted to the corresponding acid chloride, for example by reaction with thionyl chloride (optionally in an inert solvent) at a temperature from ambient to the reflux temperature which is treated with ammonia optionally in the presence of a suitable solvent e.g.
• aqueous alcohol at a temperature from 0°C to the reflux temperature to give the desired product.
• Beta-ketoester compounds of formula IX wherein R 3 represents a straight- or branched- chain alkyl group containing up to 6 carbon atoms optionally substituted by one or more halogen atoms; or a phenyl group optionally substituted by one or more groups selected from halogen, nitro, R 6 , -OR 6 and cyano; or a cycloalkyl group containing from 3 to 6 carbon atoms optionally substitued by one or more groups R 6 ; or nitro or -CO 2 R 6 may be prepared by well known procedures e.g. Beilstein 10, 682 (J.C.S. 49, 447 Perkin, Bellenot), or Nippon Kagaku Zasshi 82, 132 (1961) K. Hattori & H. Nakano, or Bull Soc. Chim Fr. (1964), 5, 945 G Braar, M. Vilkas.
• both of these stages may be performed in one step using the base and solvent combination.
• R represents an alkyl group and Z Represents halogen.
• This reaction is performed in a base e.g. sodium hydroxide in a solvent, preferably aqueous alcohol at a temperature from 0°C to 100°C.
• Esters of formula XIII or esters of formula VI wherein R 2 represents -SR 10 may be prepared by diazotisation of an amine of formula XIV:
• This reaction may be performed with sodium nitrite in a mineral acid, for example a mixture of concentrated sulphuric acid and acetic acid, at a temperature from 0°C to 60°C and subsequent reaction with:
• a mineral acid for example a mixture of concentrated sulphuric acid and acetic acid
• the diazotisation may alternatively be performed using an alkyl nitrite e.g. tert-butyl nitrite in the presence of a suitable halogenating agent (where an ester of formula XIII is desired), preferably bromoform or iodine or anhydrous cupric chloride, or at a temperature from 0 to 100°C optionally in the presence of an inert solvent, preferably acetonitrile or chloroform.
• a suitable halogenating agent where an ester of formula XIII is desired
• R 1 are as hereinbefore defined.
• the reaction conditions for this reaction are as hereinbefore described for the conversion of a compound of formula XIII to a compound of formula XIV where a cyanide reagent, e.g. copper cyanide may also be used in place of a halogenating agent; or using a diazotising reagent such as an alkyl nitrite (e.g. t-butyl nitrite in an inert solvent (e.g. acetonitrile or dichloromethane) at a temperature from -20°C to reflux temperature followed by treating the diazotised
• a cyanide reagent e.g. copper cyanide
• an inert solvent e.g. acetonitrile or dichloromethane
• B represents halogen (preferably chlorine), -OR 6 or -SR 6 , with a hydrazine of formula X.
• B represents -OR 6 or -SR 6
• this reaction is generally performed in an alcoholic solvent at a temperature from ambient to 200°C.
• B represents halogen, preferably chlorine
• the reaction is generally performed in an inert solvent, preferably tetrahydrofuran, optionally in the presence of a base eg. triethylamine at a temperature from 0°C to reflux temperature.
• Compounds of formula XV may be prepared by reaction of a hydrazine of formula X with an alkali metal salt of an
• potassium ethyl dicyanoacetate is used.
• the reaction is generally performed in the presence of an acid, e.g.
• Alkyldicyanoacetate potassium salts may be prepared by the reaction of an appropriate alkylchloroformate with malononitrile in the presence of potassium hydroxide in an inert solvent, preferably tetrahydrofuran, at a temperature from 0° to 100°C.
• m, p and q represent one or two may be prepared from the corresponding compound in which m, p and q represent zero or one by oxidation for example using
• meta-chloroperbenzoic acid in an inert solvent e.g. chloroform at a temperature from -20°C to reflux temperature.
• R 1 represents a group other than Ar, with an alkyl lithium reagent, followed by treatment of the lithiated intermediate thus obtained with a compound of formula R 10 S-SR 10 or R 10 -S-Cl.
• the alkyl lithium reagent is lithium di-isopropylamide.
• the reaction is generally carried in an aprotic solvent (e.g.
• R 10 represents an optionally subtituted alkyl or alkenyl group.
• a compound of formula R 1 - ⁇ 2 wherein R 1 is a group other than Ar and ⁇ 2 is a leaving group, in the presence of a base.
• ⁇ 2 represents for example a chlorine, bromine or iodine atom or a tosyl or mesyl group.
• Suitable bases include potassium carbonate, sodium hydride and caesium carbonate. The reaction is generally perfomed in a solvent (e.g. acetonitrile).
• Agriculturally acceptable salts of the N-substituted pyrazole derivatives of formula I may be prepared by known methods.
• Trituration with ether gave a solid which was purified by chromatography on silica gel eluting with ether/n-hexane (1:1) to furnish 5-(4-fluorophenylthio)-1-methyl-4-N-methyl-N-(2,4-difluorophenyl)carboxamido-3-trifluoromethylpyrazole, compound 93 (1.48 g) m.p. 99-100°C in the form of a white solid.
• 1,3-Dimethyl-5-hydroxypyrazole 60g was added to a mixture of phosphorus oxychloride and N,N-dimethylformamide and the resulting mixture was heated at 95-100°C for 16 to 18 hours.
• the reaction mixture was poured onto ice-water, made basic (with ammonia solution) and the resulting precipitate isolated and washed with water. Recrystallisation from hexane give 5-chloro-4-formyl-1,3-dimethylpyrazole m.p. 77-80°C.
• Methylhydrazine (25g) was added to a mixture of ethyl acetoacetate (70g) in water. The reaction mixture was heated at 70°C for 0.5 hours then cooled, extracted (chloroform) and dried
• n-Butyllithium (2.5M, 3.5 ml) was added to a solution of diisopropylamine (1.25 ml) in tetrahydrofuran under an inert atmosphere at 0°C. The solution was stirred for 45 min at 0°C and transfered to a solution of 4-ethoxycarbonyl-1-ethyl-3-trifluoromethane pyrazole (1.76 g) in tetrahydrofuran at -78°C under an inert atmosphere. The deep orange solution was stirred at -78°C for 3.5 hours after which ethyl disulphide (1.1 ml) was added. The solution was allowed to warm to room temperature overnight with stirring.
• Lawesson's reagent [2,4-bis(4-methoxyphenyl)-1,3-dithia-2,4-diphosphetane-2,4-disulphide], 2.14 g) was added to a solution of 5-chloro-4-N-(2,4-difluorophenyl)carboxamido-1-methyl-3-trifluoromethylpyrazole (3.0 g) in dry toluene (110 ml), and the mixture heated at 80-85°C for 2 hours, and then at reflux for 1.50 hours. Additional Lawesson's reagent (3.57 g) was added, with heating under reflux conditions for a further 9 hours. The solvent was evaporated in vacuo and the residue purified by
• a method for controlling the growth of weeds i.e.
• N-substituted pyrazole derivatives are normally used in the form of herbicidal compositions (i.e. in association with compatible diluents or carriers and/or surface active agents suitable for use in herbicidal compositions), for example as hereinafter described.
• the compounds of formula I show herbicidal activity against dicotyledonous (i.e. broad-leafed) and monocotyledonous (e.g. grass) weeds by pre- and/or post-emergence application.
• pre-emergence application application to the soil in which the weed seeds or seedlings are present before emergence of the weeds above the surface of the soil.
• post-emergence application application to the aerial or exposed portions of the weeds which have emerged above the surface of the soil.
• the compounds of formula I may be used to control the growth of:
• broad-leafed weeds for example, Abutilon theophrasti, Amaranthus retroflexus, Bidens pilosa, Chenopodium album, Galium aparine, Ipomoea spp. e.g. Ipomoea purpurea, Sesbania exaltata, Sinapis arvensis, Solanum nigrum and Xanthium strumarium, and
• grass weeds for example Alopecurus myosuroides, Avena fatua, Digitaria sanguinalis, Echinochloa crus-galli, Eleusine indica and Setaria spp, e.g. Setaria faberii or Setaria viridis, and
• sedges for example, Cyperus esculentus.
• the amounts of compounds of formula I applied vary with the nature of the weeds, the compositions used, the time of application, the climatic and edaphic conditions and (when used to control the growth of weeds in crop-growing areas) the nature of the crops.
• the compounds of formula I may be used to control selectively the growth of weeds, for example to control the growth of those species hereinbefore mentioned, by pre- or post-emergence application in a directional or non-directional fashion, e.g. by directional or non-directional spraying, to a locus of weed infestation which is an area used, or to be used, for growing crops, for example cereals, e.g. wheat, barley, oats, maize and rice, soya beans, field and dwarf beans, peas, lucerne, cotton, peanuts, flax, onions, carrots, cabbage, oilseed rape, sunflower, sugar beet, and permanent or sown grassland before or after sowing of the crop or before or after emergence of the crop.
• cereals e.g. wheat, barley, oats, maize and rice, soya beans, field and dwarf beans, peas, lucerne, cotton, peanuts, flax, onions, carrots, cabbage, oilseed rape, sunflower,
• the compounds of formula I may also be used to control the growth of weeds, especially those indicated above, by pre- or post-emergence application in established orchards and other treegrowing areas, for example forests, woods and parks, and
• plantations e.g. sugar cane, oil palm and rubber plantations.
• they may be applied in a directional or non- directional fashion (e.g. by directional or non-directional spraying) to the weeds or to the soil in which they are expected to appear, before or after planting of the trees or plantations at application rates between 0.25kg and 5.0kg, and preferably between 0.5kg and 4.0kg of active material per hectare.
• the compounds of formula I may also be used to control the growth of weeds, especially those indicated above, at loci which are not crop-growing areas but in which the control of weeds is nevertheless desirable.
• non-crop-growing areas include airfields, industrial sites, railways, roadside verges, the verges of rivers, irrigation and other waterways, scrublands and fallow or
• the active compounds When used for such purposes in which a total herbicidal effect is frequently desired, the active compounds are normally applied at dosage rates higher than those used in crop-growing areas as hereinbefore described. The precise dosage will depend upon the nature of the vegetation treated and the effect sought.
• the compounds of formula I When used to control the growth of weeds by pre-emergence application, the compounds of formula I may be incorporated into the soil in which the weeds are expected to emerge. It will be appreciated that when the compounds of formula I are used to control the growth of weeds by post-emergence application, i.e. by application to the aerial or exposed portions of emerged weeds, the compounds of formula I will also normally come into contact with the soil and may also then exercise a pre-emergence control on later-germinating weeds in the soil.
• the application of the compounds of formula I may b,e repeated if required.
• compositions suitable for herbicidal use comprising one or more of the N-substituted pyrazole derivatives of formula I or an agriculturally acceptable salt thereof, in association with, and preferably homogeneously dispersed in, one or more compatible agriculturally- acceptable diluents or carriers and/or surface active agents [i.e. diluents or carriers and/or surface active agents of the type generally accepted in the art as being suitable for use in herbicidal compositions and which are compatible with compounds of formula I].
• the term "homogeneously dispersed” is used to include compositions in which the compounds of formula I are dissolved in other components.
• compositions are used in a broad sense to include not only compositions which are ready for use as herbicides but also concentrates which must be diluted before use.
• the compositions contain from 0.05 to 90% by weight of one or more compounds of formula I.
• the herbicidal compositions may contain both a diluent or carrier and surface-active (e.g. wetting, dispersing, or emulsifying) agent.
• Surface-active agents which may be present in herbicidal compositions of the present invention may be of the ionic or non-ionic types, for example sulphoricinoleates, quaternary ammonium derivatives, products based on condensates of ethylene oxide with alkyl and polyaryl phenols, e.g.
• the herbicidal compositions according to the present invention may comprise up to 10% by weight, e.g.
• herbicidal compositions according to the present invention may comprise higher proportions of surface-active agent, for example up to 15% by weight in liquid emulsifiable suspension concentrates and up to 25% by weight in liquid water soluble concentrates.
• suitable solid diluents or carriers are aluminium silicate, talc, calcined magnesia, kieselguhr, tricalcium phosphate, powdered cork, adsorbent carbon black and clays such as kaolin and bentonite.
• the solid compositions (which may take the form of dusts, granules or wettable powders) are preferably prepared by grinding the compounds of formula I with solid diluents or by impregnating the solid diluents or carriers with solutions of the compounds of formula I in volatile solvents, evaporating the solvents and, if necessary, grinding the products so as to obtain powders.
• Granular formulations may be prepared by absorbing the compounds of formula I (dissolved in suitable solvents, which may, if desired, be volatile) onto the solid diluents or carriers in granular form and, if desired, evaporating the solvents, or by granulating compositions in powder form obtained as described above.
• Solid herbicidal compositions, particularly wettable powders and granules may contain wetting or dispersing agents (for example of the types described above), which may also, when solid, serve as diluents or carriers.
• Liquid compositions according to the invention may take the form of aqueous, organic or aqueous-organic solutions, suspensions and emulsions which may incorporate a surface-active agent.
• Suitable liquid diluents for incorporation in the liquid compositions include water, glycols, tetrahydrofurfuryl alcohol, acetophenone, cyclohexanone, isophorone, toluene, xylene, mineral, animal and vegetable oils and light aromatic and naphthenic fractions of petroleum (and mixtures of these diluents).
• Surface-active agents which may be present in the liquid compositions, may be ionic or non-ionic (for example of the types described above) and may, when liquid, also serve as diluents or carriers.
• Powders, dispersible granules and liquid compositions in the form of concentrates may be diluted with water or other suitable diluents, for example mineral or vegetable oils, particularly in the case of liquid concentrates in which the diluent or carrier is an oil, to give compositions ready for use.
• suitable diluents for example mineral or vegetable oils, particularly in the case of liquid concentrates in which the diluent or carrier is an oil, to give compositions ready for use.
• liquid compositions of the compound of formula I may be used in the form of self-emulsifying concentrates containing the active substances dissolved in the emulsifying agents or in solvents containing emulsifying agents compatible with the active substances, the simple addition of water to such concentrates producing compositions ready for use.
• Liquid concentrates in which the diluent or carrier is an oil may be used without further dilution using the electrostatic spray technique.
• Herbicidal compositions according to the present invention may also contain, if desired, conventional adjuvants such as adhesives, protective colloids, thickeners, penetrating agents, stabilisers, sequestering agents, anti-caking agents, colouring agents and corrosion inhibitors. These adjuvants may also serve as carriers or diluents.
• aqueous suspension concentrates which comprise from 10 to 70% of one or more compounds of formula I, from 2 to 10% of surface-active agent, from 0.1 to 5% of thickener and from 15 to 87.9%? of water;
• wettable powders which comprise from 10 to 90% of one or more compounds of formula I, from 2 to 10% of surface-active agent and from 8 to 88% of solid diluent or carrier;
• water soluble or water dispersible powders which comprise from 10 to 90% of one or more compounds of formula I, from 2 to
• liquid water soluble concentrates which comprise from 5 to 50%, e.g. 10 to 30%, of one or more compounds of formula I, from 5 to 25% of surface-active agent and from 25 to 90%, e.g. 45 to 85%, of water miscible solvent, e.g. dimethylformamide, or a mixture of water-miscible solvent and water;
• liquid emulsifiable suspension concentrates which comprise from 10 to 70% of one or more compounds of formula I, from 5 to -15% of surface-active agent, from 0.1 to 5% of thickener and from 10 to 84.9% of organic solvent;
• granules which comprise from 1 to 90%, e.g. 2 to 10% of one or more compounds of formula I, from 0.5 to 7%, e.g. 0.5 to 2%, of surface-active agent and from 3 to 98.5%, e.g. 88 to 97.5%, of granular carrier and
• emulsifiable concentrates which comprise 0.05 to 90%, and preferably from 1 to 60% of one or more compounds of formula I, from 0.01 to 10%, and preferably from 1 to 10%, of surface-active agent and from 9.99 to 99.94%, and preferably from 39 to 98.99%, of organic solvent.
• Herbicidal compositions according to the present invention may also comprise the compounds of formula I in association with, and preferably homogeneously dispersed in, one or more other pesticidally active compounds and, if desired, one or more compatible pesticidally acceptable diluents or carriers, surface-active agents and conventional adjuvants as hereinbefore described.
• synthetic pyrethroids e.g. permethrin and cypermethrin
• fungicides e.g. carbamates, e.g. methyl N-(1-butyl-carbamoyl- benzimidazol-2-yl)carbamate
• triazoles e.g. 1-(4-chloro-phenoxy)-3,3- dimethyl- 1-(1,2,4-triazol-1-yl)-butan-2-one.
• Pesticidally active compounds and other biologically active materials which may be included in, or used in conjunction with, the herbicidal compositions of the present invention, for example those hereinbefore mentioned, and which are acids, may, if desired, be utilized in the form of conventional derivatives, for example alkali metal and amine salts and esters.
• an article of manufacture comprising at least one of the N-substituted pyrazole derivatives of formula I or, as is preferred, a herbicidal composition as hereinbefore described, and preferably a herbicidal concentrate which must be diluted before use, comprising at least one of the N-substituted pyrazole derivatives of formula I within a container for the aforesaid derivative or derivatives of formula I, or a said herbicidal composition, and instructions physically associated with the aforesaid container setting out the manner in which the aforesaid derivative or derivatives of formula I or herbicidal composition contained therein is to be used to control the growth of weeds.
• the containers will normally be of the types conventionally used for the storage of chemical substances which are solid at normal ambient temperatures and herbicidal
• compositions particularly in the form of concentrates for example cans and drums of metal, which may be internally lacquered, and plastics materials, bottles or glass and plastics materials and, when the contents of the container is a solid, for example granular, herbicidal compositions, boxes, for example of cardboard, plastics materials and metal, or sacks.
• the containers will normally be of sufficient capacity to contain amounts of the N-substituted pyrazole derivative or herbicidal compositions sufficient to treat at least one acre of ground to control the growth of weeds therein but will not exceed a size which is convenient for conventional methods of handling.
• the instructions will be physically associated with the container, for example by being printed directly thereon or on a label or tag affixed thereto. The directions will normally indicate that the contents of the container, after dilution if necessary, are to be applied to control the growth of weeds at rates of application between 0.01kg and 20kg of active material per hectare in the manner and for the purposes hereinbefore described.
• a soluble concentrate is formed from :
• a wettable powder is formed from :
• Active ingredient 50% w/w
• Similar wettable powders may be prepared as described above by replacing the N-substituted pyrazole (compound 1) with other compounds of formula I.
• a water soluble powder is formed from :
• Active ingredient 50% w/w
• the seeds were sown in 70 mm square, 75 mm deep plastic pots in non-sterile soil .
• the quantities of seed per pot were as follows:- Weed species Approx number of seeds /pot
• the compounds of the invention were applied to the soil surface, containing the seeds, as described in (a). A single pot of each crop and each weed was allocated to each treatment, with unsprayed controls and controls sprayed with acetone alone.
• Crops Number of plants per pot Growth stage Maize 2 2-3 leaves Rice 4 2-3 leaves Wheat 5 2-3 leaves.
• the compounds used to treat the plants were applied to the plants as described in (a). A single pot of each crop and weed species was allocated to each treatment, with unsprayed controls and controls sprayed with acetone alone.
• the compounds of the invention used at 4kg/ha or less, have shown an excellent level of herbicidal activity together with crop tolerance on the weeds used in the foregoing experiments.
• compounds 1 to 106 When applied either pre- or post emergence at 4000g/ha or less compounds 1 to 106 gave at least 70% reduction in growth of one or more of the weed species; the compounds also showed selectivity against at least one crop species.

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• 1993
  • 1993-06-07 IL IL105939A patent/IL105939A0/xx unknown
  • 1993-06-09 EP EP93912937A patent/EP0644879A1/en not_active Withdrawn
  • 1993-06-09 CZ CZ943118A patent/CZ311894A3/cs unknown
  • 1993-06-09 CA CA002137689A patent/CA2137689A1/en not_active Abandoned
  • 1993-06-09 AU AU43247/93A patent/AU4324793A/en not_active Abandoned
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  • 1993-06-09 KR KR1019940704511A patent/KR950701913A/ko not_active Application Discontinuation
  • 1993-06-09 MA MA23205A patent/MA22906A1/fr unknown
  • 1993-06-09 WO PCT/EP1993/001466 patent/WO1993025535A1/en not_active Application Discontinuation
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  • 1993-06-09 JP JP6501120A patent/JPH07507781A/ja active Pending
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  • 1993-06-11 SI SI9300317A patent/SI9300317A/sl unknown
  • 1993-06-11 TW TW082104643A patent/TW242619B/zh active
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• 1994
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