GB1571481A

GB1571481A - 1,2,4-triazolium compounds having pesticidal and plant growth regulating properties

Info

Publication number: GB1571481A
Application number: GB4849875A
Authority: GB
Original assignee: Fisons Ltd
Current assignee: Fisons Ltd
Priority date: 1975-11-26
Filing date: 1975-11-26
Publication date: 1980-07-16
Also published as: BE848615A

Description

(54) 1,2,4-TRIAZOLIUM COMPOUNDS HAVING PESTICIDAL AND PLANT GROWTH REGULATING PROPERTIES (71) We, FISONS LIMITED, a British Company of Fison House, 9 Grosvenor Street, London Wi, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to triazolium compounds.

The invention provides a method of combating pests at a locus infested or liable to be infested with them or of regulating the growth of a desired plant at a locus at which the plant is growing or is to grow, which method comprises applying to the locus a pest-combating or a plant growth regulant amount of a compound which is a 1,2,4-triazolium salt of formula

in which R' represents a substituted or unsubstituted alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, aryl, aralkyl, or heterocyclic group; R2 and R4 are the same or different and each represents a hydrogen atom or a substituted or unsubstituted alkylthio, aryithio, or aralkylthio group or a group as defined for R1; R3 represents a group as defined for R1 or the group R5-N-R6 where R6 represents a hydrogen atom or a substituted or unsubstituted alkyl, cycloalkyl, alkenyl, alkynyl, aralkyl or aryl group; R5 represents a hydrogen atom; -SO2R7 or

where A represents an oxygen or sulphur atom, Z represents a single bond, an oxygen or sulphur atom or an -NR8 group, R7 represents a substituted or unsubstituted alkyl, aryl or aralkyl group and R8 represents a hydrogen atom or a group as defined for R7; or a substituted or unsubstituted alkyl, cycloalkyl, alkenyl, alkynyl, aralkyl or aryl group; or R5 and R5 together represent a group of formula =CR9R'0 where R9 and R'O are the same or different and each represent a hydrogen atom or a substituted or unsubstituted alkyl, aryl or aralkyl group, or R9 and R10 together represent an alkylene chain; R11 represents a group -SO2R7 or

wherein A, Z and R7 are as defined above, and Xe represents one equivalent of an anion The invention also provides a pesticidal or plant growth regulant composition comprising a compound of formula I or II together with at least one material selected from solid carriers, a liquid carrier which is a hydrocarbon which boils within the range 130--2700C, surface active agents, other pesticides, other plantgrowth regulants, antidotes, ammonium sulphate, fertilizers and bases.

Furthermore, the invention provides a new compound of formula II or of formula I where R3 represents the group R5-N-R6, and R' represents a substituted or unsubstituted alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, aralkyl, or heterocyclic group; R2 and R4 are the same or different and each represents a substituted or unsubstituted alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, aryl, aralkyl, alkylthio of more than one carbon atom, atylthio, aralkylthio or a heterocyclic group; with the proviso that R2 and R4 do not both represent methyl; Rs represents a hydrogen atom; -SO2R7 or

or a substituted or unsubstituted alkyl, cycloalkyl, alkenyl, alkynyl, aryl or aralkyl group; Re represents a hydrogen atom or a substituted or unsubstituted alkyl or aralkyl group or R5 and R8 together represent a group of formula =CR9R'0, and R" represents a group -SO2R7 or

with the proviso that, when R' represents methyl, R2 and R4 represent phenyl and X represents bromide or iodide, then R3 does not represent amino.

In a narrower group of these new compounds R1 represents a substituted or unsubstituted alkyl or aralkyl group; and R2 and R4 are the same or different and each represents a substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, cycloalkyl or cycloalkenyl group; with the proviso that R2 and R4 do not both represent methyl.

In this narrower group, in a particular embodiment, R2 and R4 are the same or different and each represents an aryl group which is unsubstituted or substituted.

In another narrower group R6 and R6 are preferably each hydrogen or optionally substituted, but preferably unsubstituted alkyl. Desirably at least one of R5 and R" represents alkyl, preferably unsubstituted, e.g., R5 represents a hydrogen atom and R6 represents an alkyl group.

The invention also provides those compounds of formula I where R3 represents the group R5NR6 and X3 represents alkyl sulphate with the exception of that compound of formula I where Xe represents methyl sulphate, R' represents methyl, R2 and R4 each represent a hydrogen atom and R5 and R8 together represent

H =C-phenyl.

In a narrower group within these new compounds, R' represents a substituted or unsubstituted alkyl, aryl or aralkyl group; and R2 and R4 are the same or different and each represents a hydrogen atom or a substituted or unsubstituted alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, aryl, aralkyl or alkylthio group. In one embodiment within this narrower group R2 and R4 are the same or different and each represents a hydrogen atom or a substituted or unsubstituted alkyl, aryl, aralkyl or alkylthio group.

The invention also provides those compounds of formula I where R' represents a substituted or unsubstituted alkyl, alkenyl, alkynyl; cycloalkyl, cycloalkenyl, aralkyl or heterocyclic group (preferably an optionally substituted, but especially an unsubstituted, alkyl group); R3 represents a substituted or unsubstituted alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, aryl, aralkyl or heterocyclic group (preferably an optionally substituted, but especially an unsubstituted, alkyl group); and R2 and R4 are the same or different and each represents a hydrogen atom or a substituted or unsubstituted alkylthio, arylthio or aralkylthio, group, or a group as defined for R3; with the proviso that R2 does not represent hydrogen or a substituted or unsubstituted alkyl or aryl group when R' represents a substituted or unsubstituted alkyl group R4 represents a substituted or unsubstituted alkyl or aryl group and R3 represents a substituted or unsubstituted alkyl group, and with the proviso that any phenyl group of the group R4 is not substituted by -NO2. Within these new compounds, there may be mentioned two important groups, namely those compounds wherein R3 represents substituted or unsubstituted aryl or aralkyl, and those compounds wherein one or more of R1, R2 R3 and R4 represents substituted or unsubstituted alkenyl, alkynyl, cycloalkyl, cycloalkenyl or aromatic heterocyclyl.

The invention also provides processes for the preparation of the new compounds, which processes are those defined below for the production of the compounds in general but applied to the production of novel compounds.

The dotted line in formula I indicates that the structure of the compound lies between

For each set of meanings for the symbols, only a single compound has found to be involved, not two isomers. The dotted line in formula II is analogous.

It can be seen that the compound of formula II is an internal salt and that of formula I is an external salt, the compound of formula II being the corresponding internal salt, where possible, of the compound of formula I where R3 represents -NHR5.

For internal salt formation, Re must represent a group -SO2R7 or

as defined hereinbefore, i.e. a group R11.

In aqueous solution of such compounds of formula I an equilibrium exists with the compounds of formula II, e.g.

Such pairs of compounds are generally of analogous activity. Differences in solubility etc., of the two types may lead to a different degree of activity between the two types.

Similarly, since in the compounds of formula lit is the cation which is responsible for the activity e.g., on plant physiology, any anion can generally be employed and it may be chosen bearing other factors in mind such as convenience in manufacture of the cation. X- can for example represent Clue, Bre, I-, NO30, SO4--, ClO4-, 1/3PO4---, BF4-, FSO3-, CH3COO-, OH-, CO3--, HCO3-, Br3-, 130, RSO3- where R represents an alkyl, aryl, alkoxyaryl or alkylaryl group, or RSO4 where R represents an alkyl group.

. Multivalent anions such as sulphate and phosphate may have associated with them a cation in addition to the 1 ,2,4-triazolium cation, for example a proton or an alkali metal or alkaline earth metal. For simplicity, such anions can be deDicted as being not further ionized though in fact they probably are further ionized.

Examples are NaSO40, KPO4ee, MgPO40, HSO40 and NaHPO40.

Generally preferred is X representing chlorine, bromide, iodide, acetate, hydroxide, sulphate, hydrogen sulphate, alkyl sulphate, p-toluene sulphonate, perchlorate or alkyl sulphonate. For convenience in manufacture when R' represents an alkyl group and X- represents alkyl sulphate, the alkyl group of the alkyl sulphate is preferably the same as R1, e.g. both methyl of both ethyl.

Preferably, Xe represents halide or alkyl sulphate, especially chloride, bromide, methyl sulphate or ethyl sulphate.

The internal salt of formula II may be prepared by reacting the external salt of formula I where R3 represents -NHR5, R5 being a group -SO2R7 or

as defined hereinbefore, i.e. a group R11, with a base, such as sodium hydroxide.

The reaction is usually conducted in the presence of an inert solvent. The reaction may be conducted for example at a temperature of W50 C.

The external salt of formula I where R3 represents R5N-R6, in which R5 represents a group R11, may be prepared by reacting an inetrnal salt of formula II with a compound of formula R6X. The reaction is usually conducted in an inert solvent and may be carried out at a temperature for instance of 0-200 C.

When R8 represents a hydrogen atom, an external salt of formula I is prepared which is a counterpart to the internal salt of formula II; but when R6 represents other than hydrogen (e.g. when the compound of formula R6X is dimethylsulphate) the external salt of formula I prepared has no counterpart of formula II.

The compounds of formula I where R3 represents Rs~NRs are preferably prepared by quaternising a 1,2,4-triazole of formula

with a compound of formula R'X, wherein R', R2, R4, R5, R8 and X are as in formula I or II. The quaternisation may be carried out with or without an inert solvent. It may be conducted at a temperature for instance 0-200 C.

The 1,2,4-triazole of formula III where R5 is hydrogen can be prepared by heating in the presence of a base, such a sodium hydroxide, a 4-amino-1,2,4triazolium derivative of formula

wherein R, R4, R6 and X- are as in formula I or II. The reaction is usually conducted in the presence of an inert solvent, e.g. water, and may be carried out for example at a temperature of 50-150 C.

The 4-amino-l,2,4-triazolium derivative of formula IV can be prepared by quaternising a 4-amino-l,2,4-triazole derivative of formula

with a compound of formula R6X, wherein R2, R4, Re and X are as in formula I or II. The quaternisation may be carried out with or without an inert solvent. It may be conducted at a temperature for instance of 0-200 C.

The compounds of formula III where R5 represents -SO2R7 or

may be prepared by reacting the corresponding compound of formula III in which R5 represents a hydrogen atom with a halide or anhydride of formula R5Y or R50R5, where Y represents a halogen, usually chlorine, atom. The reaction is usually conducted in the presence of an inert solvent and may be acrried out at a temperature of for example 50-150 C.

The compound of formula III in which R5 represents

may be prepared by reacting the corresponding compound in which R5 represents a hydrogen atom with an isocyanate or isothiocyanate of formula R8NCO or R8NCS respectively. The reaction is usually conducted at a temperature of O to 1500C, for example at ambient temperature, in an organic solvent, e.g. dimethylformamide, dimethyl sulphoxide, acetonitrile or a hydrocarbon (e.g. toluene), and preferably, when A represents a sulphur atom, also in the presence of a catalyst (usually a tertiary amine, e.g. triethylamine or pyridine, or an organotin compound, e.g. dibutyltin diacetate).

The compounds of formula III where RE and Re both represent substituted or unsubstituted alkyl, cycloalkyl, alkenyl, alkynyl, aryl or aralkyl groups or together represent a group =CR9R'0 may be prepared by reacting a compound of formula

with a hydrazine compound of the formula R5ReNNH2.

Where Re and Re represent a group =CR9R10, the compound of formula III may be reduced using for example sodium borohydride to give a further compound of formula III where Re represents hydrogen and Re represents the group - C H R9R'0.

The compound of formula I in which R5 and Re together represent a group of formula =CR9R10 may be prepared by reacting the corresponding compound in which Re and Re each represent a hydrogen atom with an aldehyde or ketone of formula R9CO R' wherein R9 and R10 are as in formula I. The reaction is usually conducted in the presence of an inert solvent and may be carried out at a temperature for example of 50200 C. Alternatively, a compound of formula V may be reacted with a compound of formula R9CO R' , and the product subsequently quaternised.

The compound of formula I in which RE represents -SO2R7 or

i.e. a group R", may be prepared by reacting the corresponding compound of formula I or II in which R5 represents a hydrogen atom with a halide or anhydride of formula R5Y or R5OR5. The reaction is usually conducted in the presence of an inert solvent and may be acrried out at a temperature of for example 50-150 C. If excess base is present, the compound of formula I produced can be converted directly to a compound of formula II.

The compound of formula I in which R5 represents

may be prepared by reacting the corresponding compound in which R5 represents a hydrogen atom with an isocyanate or isothiocyanate of formula RBNCO or R8NCS respectively. The reaction is usually conducted at a temperature of O to 1500 C, for example at ambient temperature, in an organic solvent, e.g. dimethylformamide, dimethyl sulphoxide, acetonitrile or a hydrocarbon (e.g. toluene), and preferably, when A represents a sulphur atom, also in the presence of a catalyst (usually a tertiary amine, e.g. triethylamine or pyridine, or an organotin compound, e.g. dibutyltin diacetate).

The compounds of formula I where R3 represents a group as defined for R1 may be prepared by reacting a triazole of formula

wherein R', R2 and R4 are as in formula I or II, with a compound of formula R3X where X is as defined in formula I and R3 is as defined for R1 in formula 1. The reaction is conveniently effected by heating.

The compounds of formula VI may be prepared by reacting a 4aminotriazolium salt of the formula

wherein R', R2 and R4 are as in formula I or II, and yo represents one equivalent of an anion, with nitrous acid. The nitrous acid is desirably generated in situ in a manner known per se, e.g. by reaction between an alkali-metal nitrite (e.g. sodium nitrite) and a mineral acid (e.g. hydrochloric acid) with cooling.

The compounds of formula VII may be prepared from the corresponding compounds of the formula

wherein R2 and R4 are as in formula I or II, with a compond of formula R'Y wherein R' is as in formula I or II and Y is as defined above. The reaction is conveniently effected by heating.

The present processes may be conducted for example at a pressure of 0.5 to 10, preferably 1--1.1, atmospheres.

In a preferred embodiment, a novel compound as defined above and having formula I where R' represents an alkyl group (preferably C 1 to 6 alkyl, e.g. methyl or ethyl) and R represents R5-N-R6 is prepared by quaternising the corresponding 1,2,4-triazole of formula III with a compound of formula R1X (e.g. dimethyl or diethyl sulphate, or methyl or ethyl bromide) where x represents alkyl sulphate, (e.g. methyl sulphate or ethyl sulphate) or bromide in which the alkyl group is R' (e.g. methyl or ethyl).

In one aspect, the present compounds are of formula II or are of formula I where R3 represents the group RENRe.

A preferred group within this aspect are those wherein R' represents a substituted or unsubstituted alkyl, aryl or aralkyl group; and R2 and R4 are the same or different and each represents a hydrogen atom or a substituted or unsubstituted alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, aryl, aralkyl or alkylthio group. Within this group, in one embodiment, R2 and R4 are the same or different and each represents a hydrogen atom or a substituted or unsubstituted alkyl, aryl, aralkyl or alkylthio group.

In a particular embodiment within this aspect, R2 and R4 are the same or different and each represents a hydrogen atom or an alkyl, aryl, aralkyl or alkylthio group which is unsubstituted or substituted.

In the other aspect, the present compounds are of formula I where R3 represents a group as defined for R1. In a preferred group within this aspect, R1 and R3 are the same or different and each represents a substituted or unsubstituted alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, aryl, aralkyl or aromatic heterocyclyl group.

When R', R2, R3 or R4 represents a substituted group, the substituent(s) may be for example one or more substituents selected from halogen, alkoxy, alkylthio, alkylsulphonyl, alkylsulphinyl, acyl, nitro, cyano, carboxy, esterified; salified or amidated carboxy (e.g. alkoxycarbonyl), amine, substituted (e.g. by 1 or 2 alkyl groups) amino and, except when it represents substituted alkyl, alkyl. When R5 or R6 represents a substituted alkyl, cycloalkyl, alkenyl, alkynyl, aralkyl or aryl group or R9 or R10 represents a substituted alkyl, aralkyl or aryl group, the substituent(s) may be for example one or more selected from halogen, alkoxy and nitro and, when Re, Re, RE or R10 represents a substituted aryl group, alkyl. Any substituted aryl group may for example be m-tolyl or p-tolyl. Examples of preferred substituent groups are fluorine, bromine, chlorine, methoxy, ethoxy, methylthio, ethylthio, methylsulphinyl and methylsulphonyl.

When any of the present symbols represents a substituted aralkyl group, the substituent(s) are usually on the aryl part of the group.

When any of the present symbols represents a substituted or unsubstituted group, it is preferably unsubstituted. When it is substituted, the substituents are usually the same, e.g. all chlorine or all methyl, and preferably any such substituted group is monosubstituted.

Any alkyl group involved in the present symbols is preferably of 1-15, e.g.

1-10, especially 1-6, carbon atoms, for example methyl, ethyl, propyl, isopropyl, butyl or hexyl. Any alkenyl or alkynyl group is preferably of 2--6 carbon atoms, for example vinyl or ethynyl or especially allyl or propargyl. Any cycloalkyl group is preferably of 3-7 carbon atoms, especially cyclohexyl or cyclopentyl. Any cycloalkenyl group is preferably of 3-7 carbon atoms, for example cyclopentenyl or especially cyclohexenyl. Any aryl group is preferably phenyl. Any aralkyl group is preferably phenyalkyl e.g. of 7-10 carbon atoms, especially benzyl. Any halogen is preferably fluorine, chlorine or bromine especially chlorine. Any acyl group is preferably alkanoyl of 1-7, e.g. 2-7, carbon atoms, e.g. formyl, acetyl or isobutyryl.

When any of R', R2, R3 and R4 represents a substituted or unsubstituted heterocyclyl group, it is preferably a monocyclic group, and preferably contains oxygen, nitrogen or sulphur as sole hetero ring element. Preferred such groups are furyl, pyranyl, pyrrolyl, pyridyl, quaternised pyridyl and thienyl.

Thus, preferably, R' represents an alkyl of 1--6 carbon atoms, alkenyl of 2-6 carbon atoms, alkynyl of 2--6 carbon atoms, cycloalkyl of 3-7 carbon atoms, cycloalkenyl of 3-7 carbon atoms, phenyl, phenylalkyl of 7-10 carbon atoms, furyl, pyranyl, pyrrolyl, pyridyl, quaternised pyridyl, or thienyl group, which group is unsubstituted or substituted by one or more substituents selected from halogen, hydroxy, mercapto, alkoxy of 1--6 carbon atoms, alkylthio of 1--6 carbon atoms, alkylsulphonyl of ld carbon atoms, alkylsulphinyl of 1--6 carbon atoms, alkanoyl of 1--7 carbon atoms, nitro, cyano, carboxy, esterified, salified or amidated carboxy, amino, amino substituted by 1 or 2 alkyl groups of 1-6 carbon atoms, and, except where R' represents substituted alkyl, alkyl of 1--6 carbon atoms; R2 and R4 are the same or different and each represents a hydrogen atom or an alkyl of 1--15 carbon atoms, alkylthio of 1--15 carbon atoms, alkenyl of 2-6 carbon atoms, alkynyl of 2--6 carbon atoms, cycloalkyl of 3-7 carbon atoms, phenyl, phenylthio, phenylalkyl of 7-10 carbon atoms, phenylalkylthio of 7-10 carbon atoms, furyl, pyranyl, pyrrolyl, pyridyl, quaternised pyridyl, or thienyl group, which group is unsubstituted or substituted by one or more substituents selected from halogen, hydroxy, mercapto, alkoxy of 1--6 carbon atoms, alkylthio of 1--6 carbon atoms, alkylsulphonyl of 1--6 carbon atoms, alkylsulphinyl of 1--6 carbon atoms, alkanoyl of 1--7 carbon atoms, nitro, cyano, carboxy, esterified, salified or amidated carboxy, amino, amino substituted by 1 or 2 alkyl groups of 1-15 carbon atoms, alkenyl of 2-6 carbon atoms, alkynyl of 2-6 carbon atoms, cycloalkyl of 3-7 carbon atoms and, except when it represents substituted alkyl, alkyl of 16 carbon atoms; R3 represents a group as defined for R1 or the group R5-NR6 where R6 represents a hydrogen atom or an alkyl of 1-15 carbon atoms, alkenyl or alkynyl of 2-6 carbon atoms, cycloalkyl of 3-7 carbon atoms, phenylalkyl of 7-10 carbon atoms or phenyl group, which group is unsubstituted or substituted by one or more substituents selected from halogen, alkoxy of 1--6 carbon atoms, nitro and, except when Re represents a substituted alkyl group, alkyl of 1--6 carbon atoms; R5 represents a hydrogen atom; -SO2R7 or

where A represents an oxygen or sulphur atom, Z represents a single bond, an oxygen or sulphur atom or an -NR8 group, R7 represents alkyl of 16 carbon atoms, phenyl or phenylalkyl of 7-10 carbon atoms and R8 represents a hydrogen atom or a group as defined for R7; or an alkyl of 16 carbon-atoms, alkenyl of 2-6 carbon atoms, alkynyl of 2-6 carbon atoms, cycloalkyl of 3-7 carbon atoms, phenylalkyl of 7-10 carbon atoms or phenyl group, which group is unsubstituted or substituted by one or more substituents selected from halogen, alkoxy of 16 carbon atoms, nitro and, except when R5 represents a substituted alkyl group, alkyl of 1--6 carbon atoms; or R5 or Re together represent a group of formula =CR9R10 where Rg and R10 are the same or different and each represent a hydrogen atom or an alkyl of 1--6 carbon atoms, phenyl or phenylalkyl of 7-10 carbon atoms group, which group is unsubstituted or substituted by one or more substituents selected from halogen, alkoxy of 16 carbon atoms, nitro and, except when it represents a substituted alkyl group, alkyl of 16 carbon atoms, or together represents an alkylene chain of 3-7 carbon atoms, and R1' represents a group -SO2R7 or

as defined immediately above.

In a preferred embodiment R1 represents an alkyl of 1-10 carbon atoms, phenyl or phenylalkyl of 7-10 carbon atoms group, which group is unsubstituted or substituted by one or more substituents selected from halogen, alkoxy of 1-6 carbon atoms, alkylthio of 1-6 carbon atoms, alkylsulphonyl of 1-6 carbon atoms, alkylsulphinyl of 16 carbon atoms, alkanoyl of 1-7, e.g. 2-7 carbon atoms, nitro and, except where R' represents substituted alkyl, alkyl of 1-6 carbon atoms; R2 and R4 are the same or different and each represent a hydrogen atom or an alkyl of 1-10 (e.g. 1-6) carbon atoms, alkenyl of 2-6 carbon atoms, alkynyl of 26 carbon atoms, cycloalkyl of 3-7 carbon atoms, cycloalkenyl of 3-7 carbon atoms, phenyl. phenylalkyl of 7-10 carbon atoms or alkylthio of 1-6 carbon atoms group, which group is unsubstituted or substituted by one or more substituents selected from halogen, alkoxy of 1-6 carbon atoms, alkylthio of 1-6 carbon atoms, alkylsulphinyl of 1-6 carbon atoms, alkylsulphonyl of 1-6 carbon atoms, alkanoyl of 1-7, e.g. 2-7, carbon atoms, nitro and, except when it represents substituted alkyl, alkyl of 16 carbon atoms; R3 represents R5-N-R6; R5 represents a hydrogen atom, -S02R7 or

where A represents an oxygen or sulphur atom, Z represents a single bond, an oxygen or sulphur atom, or an -NR8 group, R7 represents alkyl of 16 carbon atoms, phenyl ore phenylalkyl of 7-10 carbon atoms and Re represents a hydrogen atom or a group as defined fon R7; or an alkyl of 16 carbon atoms, phenylalkyl of 7-10 carbon atoms or phenyl group, which group is unsubstituted or substituted by one or more substituents selected from halogen, alkoxy of 1-6 carbon atoms, nitro and, except when R5 represents a substituted alkyl group, alkyl of 1-6 carbon atoms; R6 represents a hydrogen atom or an alkyl of 1-6 carbon atoms, phenylalkyl of 7-10 carbon atoms or phenyl group, which group is unsubstituted or substituted by one or more substituents selected from halogen, alkoxy of 1-6 carbon atoms, nitro and, except when R5 represents a susbtituted alkyl group, alkyl of 1-6 carbon atoms; or R5 and R6 together represent a group of formula =CR9R10 in which R9 and R10 are the same or different and each represent a hydrogen atom or an alkyl of 1-6 carbon atoms, phenyl or phenylalkyl of 7-10 carbon atoms group, which group is unsubstituted or substituted by one or mor 1,4-dimethyl-3,5-di-n-pentyl-1,2,4-triazolium 1-methyl-3,5-di-n-pentyl-4-ethyl-1,2,4-triazolium, especially the chlorides, bromides, methyl sulphates and ethyl sulphates thereof.

Specific preferred compounds include 4-amino-1-methyl-3,5-diphenyl-1,2,4-triazolium, 4-methylamino-1-methyl-3,5-diphenyl-1,2,4-triazolium, 4-methylamino-1-methyl-3,5-di(3-methylphenyl)-1,2,4-triazolium, 4-methylamino- I -ethyl-3 ,5-di(3-methylphenyl)- 1,2 ,4-triazolium, a mixture of 4-methylamino-1-ethyl-3-phenyl-5-n-pentyl-1,2,4-triazolium and 4methylamino-1-ethyl-3-n-pentyl-5-phenyl-1,2,4-triazolium, 4-amino-1-n-hexyl-1,2,4-triazolium, 4-amino-1-n-decyl-3,5-dimethyl-1,2,4-triazolium, 4-n-pentylamino-1-n-pentyl-3,5-dimethyl-1,2,4-triazolium, 4-n-pentylamino- 1 -(3-methylbutyl)-3 ,5-dimethyl- 1 ,2,4-triazolium, 4-n-hexylamino- 1 -n-pentyl-3 ,5-dimethyl- 1 ,2,4-triazolium, 4-amino-1-n-nonyl-3,5-diethyl-1,2,4-triazolium, 4-amino-1-n-decyl-3,5-diethyl-1,2,4-triazolium, 4-methylamino-1-methyl-3,5-di-n-butyl-1,2,4-triazolium, 4-ethylamino-1-n-pentyl-3,5-di-n-butyl-1,2,4-triazolium, 4-amino-1-(3-methylbutyl)-3,5-di-n-pentyl-1,2,4-triazolium, 4-methylamino-1-methyl-3,5-di-n-pentyl-1,2,4-triazolium, 4-ethylamino-1-methyl-3,5-di-n-pentyl-1,2,4-triazolium, 4-amino-1-methyl-3,5-di-(3-methylbutyl)-1,2,4-triazolium, 4-amino-1-ethyl-3,5-di-(3-methylbutyl)-1,2,4-triazolium, 4-methylamino- 1 -methyl-3,5-di-cyclopentyl- 1 ,2,4-triazolium, 4-amino-l-methyl-3,5-di-n-octyl-l ,2,4-triazolium, 4-methylamino- 1 -ethyl-3,5-di-cyclopentyl-l,2,4-triazolium, 4-amino-1-methyl-3,5-di-n-hexyl-1,2,4-triazolium, 4-amino-1-ethyl-3,5-di-n-hexyl-1,2,4-triazolium, 4-amino-1-ethyl-3,5-di-n-octyl-1,2,4-triazolium, 4-methylamino-1-methyl-3,5-di-n-octyl-1,2,4-triazolium, 4-methylamino-1-ethyl-3,5-di-n-octyl-1,2,4-triazolium, 4-methylamino-1-methyl-3,5-dicyclohexyl-1,2,4-triazolium,, and 4-amino-1-methyl-3,5-di-(p-tolyl)-1,2,4-triazolium, salts especially the chlorides or bromides and the methylsulphates of the I-methyl compounds, and the ethylsulphates of the l-ethyl compounds.

Especially preferred are the 4-methylamino- 1 -ethyl-3,5-diphenyl- 1 ,2,4-triazolium, 4-methylamino-l -ethyl-3,5-di(3-methylbutyl)- 1 ,2,4-triazolium, 4-amino- 1 -methyl-3,5-di(3-methylbutyl)- 1 ,2,4-triazolium, 4-amino-1-methyl-3,5-dipentyl-1,2,4-triazolium, 4-methylamino-1-methyl-3,5-di-n-octyl-1,2,4-triazolium, 4-methylamino-1-ethyl-3,5-di-n-octyl-1,2,4-triazolium, 4-methylamino-1-ethyl-3,5-di-(3-methylbutyl)-1,2,4-triazolium, 4-methylamino-1-n-propyl-3,5-di-n-butyl-1,2,4-triazolium, 4-methylamino-1-n-pentyl-3,5-di-n-butyl-1,2,4-triazolium, 4-methylamino-1,3,5-tri-n-butyl-1,2,4-triazolium, 4-ethylamino-1,3,5-tri-n-butyl-1,2,4-triazolium, 4-ethylamino-1-(3-methylbutyl)-3,5-di-n-butyl-1,2,4-triazolium, 4-ethylamino-1-isobutyl-3,5-di-n-butyl-1,2,4-triazolium, 4-n-pentylamino-1-(3-methylbutyl)-3,5-diethyl-1,2,4-triazolium, 4-methylamino-1-allyl-3,5-di-(3-methylbutyl)-1,2,4-triazolium, 4-n-propylamino-1-n-hexyl-3,5-diethyl-1,2,4-triazolium, 4-n-pentylamino-1-n-butyl-3,5-diethyl-1,2,4-triazolium, especially the chlorides, bromides, methyl suplhates and ethyl sulphates thereof.

The present compounds are pesticides and plant growth regulants. The compounds are particularly active on plant physiology, affecting the growth of plants so that the compounds may be used as herbicides or plant growth regulants.

They are also fungicides. They are outstandingly useful for controlling moncotyledonous or dicotyledonous weeds in crops. Thus, they are particularly active in combating wild oats, Avenafatua, A sterilis and A ludoviciana, in wheat and barley, killing or retarding the wild oats so that the wheat or barley can grow on and smother them. They may also be used to combat weeds in other crops which may be subject to infestation by wild oats, such as sugarbeet, soy beans, forage legumes, maize, french and navy beans, ryegrass, brassicas (particularly oil seed rape), flax, sunflower, peas or potatoes. They may also be used to combat weeds in crops such as cotton, sorghum, peanuts, rice, sugar cane, tobacco or tomatoes. Besides combating wild oats, they also combat blackgrass (Alopecurus myosuroides), bentgrass (Agrostis spp), barnyardgrass (Echinochloa crusgalli) and crabgrass (Digitaria spp). Activity has also been shown against pigweed (Amaranthus retroflexus) and yellow nutsedge. For use as fungicides, the compounds are preferably employed to combat fungal diseases of plants, e.g. plantation crops such as tobacco and food crops such as cereals, potatoes, French or navy beans, tomatoes or rice, especially wheat or barley.

The present compounds are normally employed in the form of compositions, which can be prepared by admixing the ingredients. Usually the compositions are initially produced in the form of concentrates, e.g. containing 0.585% of the present compound, and these are diluted with water or hydrocarbon, usually water, for application, generally such that the concentration of the compound is 0.055%, though in ultra low volume application the concentration may be higher, e.g. up to 20%. Percentages and parts in this specification are by weight unless otherwise indicated.

The compositions normally contain a surface active agent and/or a carrier.

The carrier may be a liquid, e.g. water (e.g. water used to dilute a concentrate for application). If water is employed as carrier in a concentrate, an organic solvent may also be present as carrier, though this is not usually employed. A surface active agent may advantageously be present.

Those compounds soluble in water may be used as aqueous solutions with or without a surface active agent.

The carrier may be a liquid other than water, for example an organic solvent, such as a water immiscible solvent, e.g. a hydrocarbon which boils within the range 13270"C, in which the compound is dissolved or suspended. A concentrate containing a water immiscible solvent suitably also contains a surface active agent so that the concentrate acts as a self-emulsifiable oil on admixture with water. The liquid may be a water-miscible solvent e.g. 2-methoxy ethanol, methanol propylene glycol, diethylene glycol, diethylene glycol monoethyl ether, formamide or methylformamide.

The carrier may be a solid, which may be finely divided. Examples of suitable solids are limestone, clays, sand, mica, chalk, attapulgite, diatomite, perlite, sepiolite, silicas, silicates, lignosulphonates, peat and solid fertilizers. The carrier can be of natural or synthetic origin or can be a modified natural material.

Wettable powders soluble or dispersable in water may be formed by admixing the compound in particulate form with a particulate carrier or spraying molten compound on to the particulate carrier, admixing a wetting agent and a dispersing agent and finely grinding the whole powder mixture.

An aerosol composition may be formed by admixing the compound with a propellant e.g. a polyhalogenated alkane such as dichlorodifluoromethane, and suitably also with a solvent.

A flowable suspension concentrate may be formed if the compound has a low water solubility by grinding the compound with water, a wetting agent and a suspending agent.

A flowable suspension concentrate wherein the carrier is a hydrocarbon which boils within the range 13-2700C rather than water may be formed.

Thus the present composition can for example be solid (e.g. dust or granules) and contain a solid carrier or liquid (e.g. an emulsifiable concentrate) and contain a liquid carrier which is a hydrocarbon which boils within the range 130--270"C.

The term 'surface active agent' is used in the broad sense to include materials variously called emulsifying agents, dispersing agents and wetting agents. Such agents are well known in the art.

The surface active agents used may comprise anionic surface active agents, for example soaps, mono- or di-esters of phosphoric acid with fatty alcohol ethoxylates or salts of such esters, fatty alcohol sulphates such as sodium dodecyl sulphate, sodium octadecyl sulphate or sodium cetyl sulphate, ethoxylated fatty alcohol sulphates, ethoxylated alkylphenol sulphates, lignin sulphonates, petroleum sulphonates, alkyl-aryl sulphonates such as alkyl-benzene sulphonates or lower alkylnaphthalene sulphonates e.g. butyl-naphthalene sulphonate, salts of sulphonated naphthaleneformaldehyde condensates, salts of sulphonated phenolformaldehyde condensates, or more complex sulphonates such as the amide sulphonates e.g. the sulphonated condensation product of oleic acid and N-methyl taurine or the dialkyl sulphosuccinates e.g. the sodium sulphonate of dioctyl succinate. Anionic surface active agents may tend to result in precipitation if employed in some formulations with the present, cationic, compounds. Any surface active agent should be so chosen of course as to avoid this for any particular formulation envisaged.

The surface active agents may also comprise non-ionic agents, for example condensation products of fatty acid esters, fatty alcohols, fatty acid amides or fatty-, alkyl- or alkenyl-substituted phenols with ethylene oxide, fatty esters of polyhydric alcohol ethers e.g. sorbitan fatty acid esters, condensation products of such esters with ethylene oxide e.g. polyoxyethylene sorbitan fatty acid esters, block copolymers of ethylene oxide and propylene oxide, acetylenic glycols such as 2,4,7,9-tetramethyl-5-decyn-4,7-diol, or ethoxylated acetylenic glycols.

The surface active agents may also comprise cationic agents, for example alkyl- and/or aryl-substituted quaternary ammonium compounds such as cetyl trimethylammonium bromide or ethoxylated tertiary fatty amines.

Preferred surface active agents include ethoxylated fatty alcohol sulphates, lignin sulphonates, alkyl-aryl sulphonates, salts of sulphonated naphthaleneformaldehyde condensates, salts of sulphonated phenol-formaldehyde condensates, dialkyl sulphosuccinates, alkyl phenol ethoxylates, and fatty alkyl ethoxylates.

Non-ionic surface active agents are preferred.

Higher quantities of surface active agent, e.g. 550% of concentrate, than is normally present in commercial pesticidal or plant growth regulant compositions have been found to increase considerably the activity of the present compounds, even in some cases to several times the original activity.

The surface active agent employed to produce this potentiating effect may be selected from those described above. It is preferably a non-ionic surface active agent, especially an alkyl-substituted phenol condensed with ethylene oxide, e.g. tributylphenol condensed with 11 moles of ethylene oxide (available under the trade mark Sapogenat Tl 10). The potentiating surface active agent may be admixed with the present compound for instance at the point of use, e.g. in a spray tank, or before, e.g. in a concentrate. Preferably the amount of potentiating surface active agent applied in a spray of the present compound is 0.15%, especially 1%.

The present active compound may be admixed with another pesticide, e.g. herbicide, insecticide or fungicide, or with another plant growth regulant. The invention provides a one pack presentation, in which the present compound is already mixed with other pesticide or plant growth regulant, and also a single package designed to hold the present compound and other pesticide or plant growth regulant in separate containers, for mixing, e.g. in a spray tank, for application. Particular advantages are obtained with mixtures with another herbicide. The present compound may be used sequentially with another herbicide, e.g. one herbicide applied before planting or before emergence of a crop and the other herbicide applied after emergence of the crop.

The other herbicide may be for example one or more of a phenoxyaliphatic acid, substituted urea, triazine, phenol, nitrile, bipyridylium compound, substituted benzoic acid, halogenated aliphatic acid, carbamate, thiocarbamate, chloroacetamide, diazine or arsenic herbicide. In respect of selective herbicidal compositions for post-emergence use, the present compound may be used in admixture with for example a substituted phenoxyaliphatic acid; in respect of selective herbicidal compositions for pre-emergence use, the present compound may be used in admixture with for example a substituted urea or triazine; in respect of sequential selective herbicidal use, one may apply for example before emergence of the crop S-2,3-dichloroaliyl di-isopropylthiocarbamate or S-2,3,3trichloroallyl di-isopropylthiocarbamate and the present compound after emergence of the crop.

The phenoxyaliphatic acid generally comprises alkyl and/or halogen substituted phenoxyaliphatic acids, and their salts, for example alkali metal, amine and alkanolamine salts, and functional derivatives, for example esters and amides.

These compounds may be of activity such that they are recognised as commercial herbicides, or may be of only slight herbicidal activity. Examples of the substituted phenoxyaliphatic acids which may be mentioned include 2,4-dichlorophenoxyacetic acid, 2-(2,3-dichlorophenoxy)propionic acid, 2-methyl-4-chlorophenoxyacetic acid, 2,4,5-trichlorophenoxyacetic acid, gamma-2,4-dichlorophenoxybutyric acid, gamma-2-methyl-4-chloro-phenoxybutyric acid, alpha-2-methyl-4 chlorophenoxypropionic acid, 2-(4-[2,4-dichlorophenoxy]phenoxy)propionic acid and 2-(4-[4-chlorophenoxy]phenoxy)propionic acid.

The substituted urea generally comprises a tri- or tetra-substituted urea such as N'-(3-chloro-4-methoxyphenyl)-N,N-dimethylurea, N'-(3-chloro-4-methylphenyl)-N,N-dimethylurea, N'-parachlorophenyl-N,N-dimethylurea, N-butyl-N' (3,4-dichloorphenyl)-N-methylurea, N'-parachlorophenyl-O,N,N-trimethylisourea, N'-p-chlorophenyl-N-methoxy-N-methylurea, N,N-dimethyl-N'-phenylurea, 3-(4-bromophenyl)-1-methoxy-1-methylurea, 1-(2-benzothiazolyl)-3-methylurea, N,N-dimethyl-N'-(4-[l-methylethyl] D henyl)urea, N'-(3,4-dichlorophenyl)-Nmethoxy-N-methylurea or N,N-dimethyl-N'-[3-(trifluoromethyl)phenyl]urea.

The triazine herbicide generally comprises 2-chloro-4-(1-cyano-1-methylamino)-6-ethylamino- 1 ,3,5-triazine or 2-isopropylamino-4-(3-methoxypropyl amino)-6-methylthio-l,3,S4riazine or a compound of the formula:

where Hal is a halogen atom, OY group or SY group, where Y is an alkyl group, R' and R"' are the same or different and are hydrogen or alkyl and R" and R"" are the same or different alkyl groups, such as 2-ehloro-4,6-bisethylamino-1,3,5-triazine, 2 chloro-4-ethylamino-6-diethylamino- 1,3,5-triazine, 2-chloro-6-ethylamino-4-iso propylamino- 1 ,3,5-triazine or 2,4-bis(isopropylamino)-6-methylthio- 1,3 ,5-triazine.

The phenol herbicide generally comprises 4,6-dinitro-o-cresol, 4,6-dinitro-2sec-butylphenol or pentachlorophenol. The nitrile herbicide generally comprises 3,5-diiodo-4-hydroxybenzonitrile, 3,5-dibromo-4-hydroxybenzonitrile or 2,6dichlorobenzonitrile. The bipyridylium herbicide generally comprises 1,1'dimethyl-4,4'-bipyridylium dichloride or 1,1 '-ethylene-2,2'-bipyridylium dibromide. The substituted benzoic acid herbicide generally comprises 2,3,6trichlorobenzoic acid, 2-methoxy-3,6-dichlorobenzoic acid or N-(l,l- dimethylpropynyl)-3 , 5-dichlorobenzamide. The halogenated aliphatic acid herbicide generally comprises trichloroacetic acid or 2,2-dichloropropionic acid.

The carbamate herbicide generally comprises isopropyl N-(3-chlorophenyl) carbamate, 4-chloro-2-butynyl N-(3-chlorophenyl)carbamate, methyl 3-(m-tolylcarbamoyloxy)phenylcarbamate or D-N-ethyl-2-(phenylcarbamoyloxy)propionamide. The thiocarbamate herbicide generally comprises S-ethyl N,N-dipropyl-thiocarbamate, S-ethyl N,N-diisobutylthiocarbamate, S-(2,3-dichloroallyl) N,N-diisopropylthiocarbamate, S-ethyl N-ethyl-N-cyclohexylthiocarbamate, Spropylbutylethylthiocarbamate or S-(2,3,3-trichloroallyl) N,N-diisopropylthiocarbamate. The chloroacetamide herbicide generally comprises N,N-diallyl-2chloroacetamide or N-isopropyl-2-chloroacetanilide. The diazine herbicide generally comprises 5-bromo-6-methyl-3-sec-butyluracil, 3-cyclohexyl-5,6-tri- methyleneuracil, 5-amino-4-chloro-2-phenyl-3-pyridazinone or 1,2-dihydropyridazine-3,6-dione. The arsenic herbicide generally comprises a salt of methane arsonic acid or cacodylic acid. Other herbicides which may be used as the second herbicide include 1,2-dimethyl-2,5-diphenylpyrazolium ion, ethyl N-benzoyl-N (3,4-dichlorophenyl)alanine, N-isobutyl-2-oxo-1-imidazolidine-carboxamide aminotriazole, 2,3-dichloro- 1 ,4-naphthoquinone, 4-amino-3 ,5,6-trichloropicolinic acid, N,N-dimethyl-2,2-diphenylacetamide, 2,6-dinitro-N,N-dipropyl-4-trifluoromethylaniline, N-butyl-N-ethyl-2,6-dinitro-4-trifluoromethylaniline, S,S,S-tributyl phosphorotrithioate, 2-ethoxy-2,3-dihydro-3,3-dimethyl-5-benzofuranyl methylsulphonate, 4-chloro-2-oxobenzothiazolin-3-yl acetic acid, 3-isopropyl-2, 1 ,3-benzo- thiadiazinon-(4)-2,2-dioxide, 3,5-dibromo-4-hydroxybenzaldehyde 2,4-dinitrophenyloxime, methyl 2-chloro-3-(4-chlorophenyl)propionate, 2-chloroethyltri- methylammonium chloride, 4-methylsulphonyloxy-2-butynyl m-chlorocarbanilate, isopropyl 2-(N-benzoyl-3-chloro-4-fluoroanilino)propionate, methyl 2-(N-benzoyl3-chloro-4-fluoroanilino)propionate, 2-chloro-N-(1,3-dioxolan-2-ylmethyl)-2',6'-di methylacetanilide, 2-chloro-l-(3-ethoxy-4-nitrophenoxy)-4-trifluoromethylbenzene, methyl 2-(4-[2',4'-dichlorophenoxy]phenoxy)propionate or isobutyl 2-(4 [4'-chlorophenoxy]phenoxy)propionate.

The other herbicide may particularly be another herbicide which combats wild oats in cereal crops.

In particular embodiments, the present compound and particularly one specified above, advantageously one specified as being preferred or especially preferred, e.g.

4-methylamino- 1 -ethyl-3,5-diphenyl- 1,2,4-triazolium chloride or ethyl sulphate or especially 4-methylamino- I -methyl-3,5-dipentyl- I ,2,4-triazolium chloride or methyl sulphate is used (a) in admixture with 4-chloro-2-butynyl 3chlorophenyl-carbamate, 1,2-dimethyl-3,5-diphenylpyrazolium ion, alpha-2-methyl-4-chlorophenoxypropionic acid, N'-(3-chloro-4-methoxyphenyl)-N,N-dimethylurea, N'-(3-chloro-4-methylphenyl)-N,N-dimethylurea or ethyl N-benzoyl-N-(3 ,4- dichlorophenyl)aniline, or (b) after emergence of the crop following use before emergence of the crop of S-2,3-dichloroallyl di-isopropylthiocarbamate or S-2,3,3trichloroallyl di-isopropylthiocarbamate.

The present compound may be used in admixture or sequence with another fungicide, particularly another cereal fungicide. The other fungicide may be for instance one or more of maneb (polymeric manganese ethylenebisdithiocarbamate), zineb (zinc ethylenebisdithiocarbamate), manocozeb (which can be regarded as a mixture of maneb and zineb), thiram (tetramethylthiuram disulphide), ditalimfos (O,O-diethyl phthalimidophosphonothioate), tridemorph (2,6-dimethyl-4-tridecylmorpholine), fluotrimazole (I -[diphenyl-(3-trifluoro- methylphenyl)methyl]- I ,2,4-triazole), ethirimol (5-butyl-2-ethylamino-4-hydroxy-6- methylpyrimidine), trifluorine (1 ,4-di[2,2,2-trichloro- I -formamido- ethyl]piperazine), pyracarbolid (3,4-dihydro-6-methylpyran-5-carboxanilide).- zineb-ethylene thiuramdisulphide adduct, carbendazim (methyl benzimidazol-2ylcarbamate), captafol (3a,4,7,7a-tetrahydro-N-[ 1,1 ,2,2-tetrachloroethanesulphenyl]phthalimide), thiophanate (1 ,2-di[3-ethoxycarbonyl-2-thioureido]- benzene), proprineb (polymeric zinc propylenebisdithiocarbamate), oxycarboxin (2,3-dihydro-6-methyl-5-phenylcarbamoyl- I ,4-oxathiin 4,4-dioxide), quintozene (pentachloronitrobenzene), benomyl (methyl l-[butylcarbamoyllbenzimidazol-2- ylcarbamate) and benadil (2-iodobenzanilide).

The present compound may be used in admixture or sequence with an insecticide, particularly a cereal insecticide. The insecticide may be for instance one or more of demeton-S-methyl (S-2-ethylthioethyl O,O-dimethyl phosphorothioate), dimethoate (O,O-dimethyl S-methylcarbamoylmethyl phosphorodithioate), formothion (S-[N-formyl-N-methylcarbamoylmethyl] O,O-dimethyl phosphorodithioate), oxydemeton-methyl (S-2-ethylsulphinylethyl O,O-dimethyl phosphorothioate), pirimicarb (2-dimethylamino-5,6-dimethylpyrimidin-4-yl dimethylcarbamate), thiometon (S-2-ethylthioethyl O,O-dimethyl phosphorodithioate), BHC (benzene hexachloride), aldrin (I,2,3,4,10,10-hexachloro- 1 ,4a,4,5,8,8a-hexahydro-exo- 1 ,4-endo-5,8-dimethanonaphthalene), fenitrothion (O,O-dimethyl O-4-nitro-m-tolyl phosphorothioate), omethoate (O,O-dimethyl Smethylcarbamoylmethyl phosphorothioate), pirimiphos-methyl (0-2-diethylamino-6-methylpyrimidin-4-yl O,O-dimethyl phosphorothioate) and DDT (1,1,1trichloro-2,2-di [chlorophenyl] ethane).

The ratio of the present compound to the other pesticide or plant growth regulant may vary over a wide range according to the particular compounds involved and the intended use. In general the ratio of present compound to other pesticide or plant growth regulant lies in the range 1:0.1 to 1:15.

The present compounds may be in admixture with non-phytotoxic oils, e.g.

Agri-Oil Plus, Sun Oil I lE or Fyzol E.

The compounds may be in admixture with an antidote (a substance having the property of improving the selectivity of herbicides), e.g. N,N-diallyl-2,2dichloroacetamide or 1,8-naphthalic anhydride.

The compounds may be in admixture with ammonium sulphate which improves the activity of some herbicides. For this, it may be applied for example at 0.5-20, e.g. 2, kg per hectare, and may be admixed with the present compound in a spray tank immediately before use.

The compounds may be in admixture with fertilizers.

When a compound of formula II is employed in which X3 represents an equivalent of an anion of a strong acid, e.g. when the compound is an alkyl sulphate, the compound may be in admixture with a base, e.g. sodium acetate or sodium hydroxide, so that the compositions applied in use are not so acid as to harm the application equipment or a crop treated.

In the use of the present compounds as total herbicides, high rates of application, for example at least 10 kg per hectare, such as 125 kg per hectare, of the compounds are usually required, unless they are mixed with other herbicides, in which case the rate can be reduced.

In the use of the present compounds as selective herbicides, the rate of application is usually much lower and may be for example 0.5-10, e.g. 0.5-8, kg per hectare, such as 14 kg per hectare.

In the use of the compounds as plant growth regulants, low rates of application are usually required such as 0.14, e.g. 0.5-1, kg per hectare.

For use as fungicides, the compounds are generally applied at a rate of 1--6 kg per hectare.

Since it is the cation in the compounds of formula III which is responsible for the activity, it is the amount of such cation rather than of the compound as a whole which is to be counted in the rates specified above.

The present compounds may be applied to plants, the soil, land, aquatic areas or inanimate or stored materials, e.g. textiles, paper, leather or wood, susceptible to fungal attack. They are preferably used as herbicides, particularly selective herbicides, especially for selectively combating weeds by application to a locus at which a crop e.g. a food crop and especially a cereal crop such as wheat or barley is growing or is to grow. Thus, the compounds may be applied pre- or post-planting of the crop. They may be employed for pre-emergence use or preferably postemergence use. They may be used especially to combat wild oats particularly in cereal crops. The compounds may be used as fungicides, particularly for combating fungal diseases of plants, e.g. cereal powdery mildew. Thus, the compounds may be used to protect plants from weeds and fungus.

The invention is illustrated by the following Examples.

Example 1.

A mixture of 4-amino-3,5-diphenyl-1,2,4-triazole (236 parts) and dimethyl sulphate (126 parts) was heated at 2000C for 10 minutes. The product was then cooled and ground up under petroleum and then filtered off. The white solid was then dried to give 4-amino-i -methyl-3,5-diphenyl- 1 ,2,4-triazolium sulphate (341 parts, 94% yield), melting point-52--60"C.

Found: C, 52.55; H, 5.34; N, 15.04% C18H18N4O4Srequires: C, 53.02; H, 5.01; N, 15.46% Example 2.

A mixture of 4-amino-3,5-diphenyl-1,2,4-triazole (236 parts) and dimethyl sulphate (126 parts) was heated at 200"C for 10 minutes. The resulting hot oil was dissolved in water (2,000 parts), cooled to room temperature and treated with normal aqueous sodium hydroxide solution (1,000 parts). The mixture was then heated at 1000C for two hours with occasional stirring. The solid product was filtered off, washed with water and recrystallised from isopropanol to give 4 methylamino-3,5-diphenyl-1,2,4-triazole (134 parts, 54% yield) (melting point 195--196"C). This product was then heated at 2000C for 10 minutes with dimethyl sulphate (67 parts). The resulting oil was cooled to solidify and ground up under petroleum. The white solid was filtered off and dried to give l-methyl-4 methylamino-3,5-diphenyl-l,2,4-triazolium methyl sulphate (169 parts, 84% yield).

Found: C, 53.95; H, 5.34; N, 14.57% C17H20N4O4S requires: C, 54.24; H, 5.36; N, 14.88% Examples 3 to 65.

The following compounds were prepared by methods analogous to those described in Examples 1 and 2, employing the appropriate starting material and an appropriate sulphate or halide quaternising agent: 3. 4-amino- 1 -methyl-3,5-diphenyl-l ,2,4-triazolium p-toluenesulphonate, mp 57600.

4. 4-amino-I -methyl-3,5-bis(4-methylphenyl)- 1 ,2,4-triazoliummethyl sulphate, mp 62--66".

5. 4-amino-1-methyl-3,5-bis(4-methoxyphenyl)-1,2,4-triazoliummethyl sulphate, mp 54-58 .

6. amino-1-ethyl-3,5-bis(4-methoxyphenyl)-1,2,4-triazolium ethyl sulphate, hygroscopic solid.

7. 4-amino-l -ethyl-3,5-bis(4-chlorophenyl)- 2,4-triazolium ethyl sulphate, mp 62-65 .

8. 4-amino-1-ethyl-3,5-bis(4-methylphenyl)-1,2,4-triazolium ethyl sulphate, mp 36-42 .

9. 4-amino-1-ethyl-3,5-bis(4-methoxyphenyl)-1,2,4-triazolium ethyl sulphate, mp 36-42 .

10. 4-methylamino-1-methyl-3,5-bis(4-methoxyphenyl)-1,2,4-triazolium methyl sulphate, mp 5658 .

11. 4-ethylamino-1-methyl-3,5-diphenyl-1,2,4-triazolium methyl sulphate, mp 87900.

12. 4-methylamino-1-ethyl-3,5-diphenyl-1,2,4-triazolium ethyl sulphate, m.p.

148-51 .

13. 4-methylamino-1-ethyl-3,5-bis(4-methylphenyl)-1,2,4-triazoliurn ethyl sulphate, hygroscopic solid.

14. 4-amino-1-benzyl-3,5-diphenyl-1,2,4-triazolium chloride, mp 96-98 .

15. 4-amino-3,5-dichlohexyl-1-methyl-1,2,4-triazolium methyl sulphate, msp.

47. 4-amino-l-n-nonyl-3,5-diethyl-l 2,4-triazolium bromide, hygroscopic solid.

48. 4-amino-I -n-decyl-3,5-diethyl- 1 ,2,4-triazolium bromide, hygroscopic solid.

49. 4-methylamino-l -methyl-3,5-di-n-butyl-l ,2,4-triazolium methylsulphate, oil.

50. 4-ethylamino-1-n-pentyl-3,5-di-n-butyl-1,2,4-triazolium bromide, m.p.

63-65 C.

51. 4-amino- 1 -(3-methylbutyl)-3,5-di-n-pentyl- 1,2,4-triazolium bromide, m.p.

105--106"C.

52. 4-methylamino-1-methyl-3,5-di-n-pentyl-1,2,4-triazolium methylsulphate, oil.

53. 4-ethylamino-1-methyl-3,5-di-n-pentyl-1,2,4-triazolium methylsulphate, oil.

54. 4-amino-1-methyl-3,5-di(3-methylbutyl)-1,2,4-triazolium methylsulphate, oil.

55. 4-amino-1-ethyl-3,5-di(3-methylbutyl)-1,2,4-triazolium ethylsulphate, m.p.

62-66 C.

56. 4-methylamino- 1 -methyl-3,5-di-cyclopentyl- 1,2,4-triazolium methylsulphate, m.p. 68-70 C.

57. 4-amino-1-methyl-3,5-di-n-octyl-1,2,4-triazolium methylsulphate, oil.

58. 4-methylamino-1-ethyl-3,5-di-cyclopentyl-1,2,4-triazolium ethylsulphate, m.p.

60660C.

59. 4-amino-1-methyl-3,5-di-n-hexyl-1,2,4-triazolium methyl sulphate, oil.

60. 4-amino-1-ethyl-3,5-di-n-hexyl-1,2,4-triazolium ethylsulphate, oil.

61. 4-amino-1-ethyl-3,5-di-n-octyl-1,2,4-triazolium ethylsulphate, oil.

62. 4-methylamino-1-methyl-3,5-di-n-octyl-1,2,4-triazolium methyl sulphate oil.

63. 4-methylamino-1-ethyl-3,5-di-n-octyl-1,2,4-triazolium ethylsulphate oil.

64. 4-methylamino-1-methyl-3,5-dicyclohexyl-1,2,4-triazolium methylsulphate, m.p. 116--1200C, and 65. 4-amino-l-methyl-3,5-di-(p-tolyl)-l ,2,4-triazolium methylsulphate, m.p.

62--66"C.

Example 66. n-Caproic hydrazide (260 parts) and sodium methoxide (108 parts) were dissolved in methanol (100 parts). Ethyl thiobenzoate (332 parts) in methanol (500 parts) was then added to the solution, and the reaction mixture was allowed to stand overnight at room temperature. It was then evaporated to dryness keeping the temperature below 40"C. The residue was then dissolved in ice water (6000 parts), the solution then being acidified to pH=6 with acetic acid and filtered. The solid, after washing with water, was dissolved in water (2500 parts) containing hydrazine hydrate (200 parts) and hydrazine dihydrochloride (42 parts). The solution was heated at reflux for 3 hours under nitrogen and the solid material filtered off and recrystallised from butanol, to yield 202 parts of 4-amino-3-npentyl-5-phenyl-1,2,4-triazole, m.p. 190-193 C.

Analysis: C H N Calculated: 67.79 7.88 24.33% Found: 68.01 8.22 24.38% On reaction with dimethylsulphate and then with diethylsulphate as described in Example 2, a mixture of 4-methylamino-l-ethyl-3-phenyl-5-n-pentyl-l,2,4- triazolium ethylsulphate and 4-methylamino- 1 -ethyl-3-n-pentyl-5-phenyl- 1,2,4triazolium ethyl sulphate was obtained as an oil.

Examples 67 to 84.

Seeds of wheat (Triticum aestivum), barley (Hordeum vulgare) and wild oats (Avena spp) were sown in anodised aluminium pots, 20 cm long x 10 cm wide x 5 cm deep, containing John Innes I potting compost. They were then watered and placed in a controlled environment room (temperature 22"C, relative humidity 6585%, artificial illumination of 17,000 lux for 14 hours per day) for 14 days. The emergent seedlings were then sprayed with the compounds listed below in aqueous solution containing 2,000 ppm of the condensation product of nonylphenol with ethylene oxide as wetting agent. The dosage rate was equivalent to 2.8 kg of the cation of the compound in 375 litres per hectare. The plants were then returned to the controlled environment room for a further 14 days and visually assessed for herbicidal effect by comparison with untreated controls. Differences from the controls were scored on a scale from 0 to 100 in which 0 signifies no effect and 100 signifies complete suppression and are tabulated below.

Herbicidal effect Compound Wheat Barley Wild oats 4-amino-1-methyl-3,5-diphenyl-1,2,4triazolium methyl sulphate 0 3 65 4-methyl amino-1-methyl-3 , 5-diphenyl-1, 2,4- triazolium methyl sulphate 5 3 75 4-ethyl amino- 1-methyl-3, 5-diphenyl- 1,2,4- triazolium methyl sulphate 7 3 55 4-methyl amino- 1-ethyl-3, 5-diphenyl-1, 2,4- triaolium ethyl sulphate 4 5 65 4-methylamino-1-ethyl-3,5-bis-(4-methylphenyl)1,2,4-triazolium ethyl sulphate 8 10 35 4-amino-3,5-dicyclohexyl-1-methyl-1,2,4- triazolium methyl sulphate 0 5 80 4-methylamino-3, 5-di cyclohexyl- 1-methyl 1,2,4-triazolium methyl sulphate 5 5 70 4-amino-1-methyl-3,5-dipentyl-1,2,4- traizolium methyl sulphate 5 5 70 4-methyl amino- 1-methyl-3,5-dipentyl- 1,2,4-triazolium methyl sulphate 20 5 80 4-ethylamino-1-methyl-3,5-dipentyl1,2,4-triazolium methyl sulphate 20 20 70 4-methyl amino-l- ethyl-3 ,5-dip entyl1,2,4-triazolium ethyl sulphate 30 20 70 4-amino-1-methyl-3,5-di(3-methylbutyl)1,2,4-triazolium methyl sulphate 5 5 80 4-methylamino-1-ethyl-3,5-dibutyl-1,2,4triazolium ethyl sulphate 5 5 80 4-ethylamino-1-methyl-3,5-dibutyl-1, 2,4- triazolium methyl sulphate 5 5 80 3 ,5-dibutyl-1-ethyl-4-ethylamino- 1,2,4triazolium ethyl sulphate 10 5 90 4-amino-1-ethyl-3,5-di(3-methylbutyl)1,2,4-triazolium ethyl sulphate 5 5 80 4-amino-1-methyl-3,5-dicyclopentyl- 1,2,4-triazolium methyl sulphate 5 5 70 1-methyl-4-methylamino-3,5-di(3-cyclohexen l-yl)-1,2,4-triazolium methyl sulphate 5 5 70 Examples 85-94.

In a test as described in Examples 67 to 84, and against additional plant species, the following results were obtained.

Herbicidal effect Barn Yellow Wild Black yard Crab Nuts Compound Wheat Barley oats grass grass grass edge 4-methyl amino- 1-ethyl- 3,5-di-(3-methylbutyl)1,2,4-triazolium ethyl sulphate 40 10 100 80 80 60 NT 4-methylamino-1-npropyl-3,5-di-n-butyl1,2,4-triazolium bromide 40 5 100 70 90 80 75 4methylamino-1,3,5 tri-n-butyl- 1,2,4traizolium bromide 40 5 100 60 90 80 NT 4-ethylamino-1,3,5tri-n-butyl- 1,2,4triazolium bromide 40 20 100 80 100 80 NT 4-ethylamino-1-i sobutyl3,5-di-n-butyl-1,2,4triazolium bromide 30 10 100 80 90 90 NT 4-n-pentylamino-1-(3- methylbutyl)-3,5diethyl-1,2,4-triazolium bromide 50 15 100 90 90 90 NT 4-methylamino-1-allyl3,5-di-(3-methylbutyl)1,2,4-triazolium bromide 40 30 100 70 90 90 NT 4-n-propylamino-1-n- hexyl-3,5-diethyl-1,2,4triazolium bromide 40 10 100 70 100 90 NT 4-n-pentylamino-1-n. butyl-3, 5-diethyl1,2,4-triazolium bromide 50 15 100 80 90 70 NT Mixture of 4-methylamino 1-ethyl-3-phenyl-5-n- pentyl and 4-methylamino1-ethyl-3-n-pentyl-5phenyl-1,2,4-triazolium ethyl sulphate 20 20 70 30 30 80 NT NT = not tested.

Examples 95-101.

In a test as described in Examples 67 to 84, but against different plant species, and at an application rate of 0.7 kg/ha, the following results were obtained: Herbicidal effect Pale Corn Chick May Persi Mari Pig Compound weed weed Cleavers caria Fathen gold weed 4-methylamino-1-n- pentyl-3, 5-di-n-butyl 1,2,4-triazolium bromide 30 30 80 90 70 90 70 4-ethylamino-1,3,5-tri n-butyl-1,2,4-triazolium bromide 30 30 90 100 80 100 90 4-ethylamino-1-(3-methyl butyl)-3,5-di-n-butyl 1,2,4-triazolium bromide 80 70 100 100 80 100 100 4-ethyl amino-i-i sobutyl- 3,5-di-n-butyl-1,2,4 triazolium bromide 50 50 90 100 90 90 90 4-n-pentylamino-1-(3- methylbutyl)-3,5-diethyl 1,2,4-triazolium bromide 40 40 100 100 90 100 90 4-np ropyl amino- 1-n hexyl-3, 5-di ethyl- 1,2,4-triazolium bromide 40 100 90 100 100 100 100 4-n-pentylamino-1-n- butyl-3, 5-diethyl- 1, 2, 4triazolium bromide 80 80 80 100 90 90 80 Examples 102-104.

Aqueous acetone solutions containing 500 mg per litre (based on the cation) of the compounds listed below together with 125 mg per litre of a non-ionic wetting agent were sprayed on the foliage of young barley plants (3 leaf stage).

The treated plants, together with controls treated with wetting agent alone, were inoculated 24 hours after the chemical application with spores of cereal powdery mildew, Erysiphe graminis.

The plants were then placed in a controlled environment room held at 160C and 60% relative humidity for 10 days when the percentage of disease control was assessed.

The degree of control by the compounds was found to be: Compound %control 4-amino-3,5-diheptyl- I-methyl- 1,2,4-triazolium methyl sulphate 98 1-methyl-4-methylamino-3,5-dipentyl-1,2,4 triazolium methyl sulphate 90 l-methyl-4-methylamino-3, 5-dicyclohexyl 1,2,4-triazolium methyl sulphate 92 Example 105.

A wettable powder formulation containing 50% of l-methyl-4-methylamino- 3,5-diphenyl-l,2,4-triazolium cation was prepared by fluid energy milling the following: l-methyl-4-methylamino-3,5-diphenyl-l ,2,4 triazolium methyl sulphate 74.3% 'Arkopon T highly concentrated' (64% sodium N-oleoyl-N-methyltauride) 5% China clay 20.7% Example 106.

A wettable powder formulation containing 50% of 1-ethyl-4-methylamino-3,5- diphenyl- I ,2,4-triazolium cation was prepared by fluid energy milling the following: I -ethyl-4-methylamino-3 ,5-diphenyl- 1,2,4- triazolium ethyl sulphate 72.4% 'Arkophon T highly concentrated' (64% sodium N-oleoyl-N-methyltauride) 5% China clay Example 107.

A wettable powder formulation containing 50% of 4-ethylamino-l -methyl-3,5- diphenyl- 1 ,2,4-triazolium cation was prepared by fluid energy milling the following: 4-ethylamino-1-methyl-3,5-diphenyl-l 1,2,4- triazolium methyl sulphate 69.9% 'Arkophon T highly concentrated' (64% sodium N-oleoyl-N-methyltauride) 5% China clay 25.1% Example 108.

A wettable powder formulation containing 50% of l-methyl-4-methylamino 3,5-di(m-tolyl)-l ,2,4-triazolium cation was prepared by fluid energy milling the following: 1 -methyl-4-methylamino-3,5-di(m-tolyl)- 1,2,4 triazolium methyl sulphate 69% 'Arkophon T highly concentrated' (64% sodium N-oleolyl-N-methyltauride) 5% China clay 26% Example 109.

A 40% aqueous concentrate of 4-amino-l-methyl-3,5-diphenyl.l,2,4- triazolium cation was prepared by admixing the following: 4-amino-l -methyl-3,5-diphenyl- 1,2,4-triazolium methyl sulphate 57.8% weight/volume water to 100% Example 110.

An 8% aqueous concentrate of l-ethyl-4-ethylamino-3,5-diphenyl-l,2,4- triazolium cation was prepared by admixing the following: I -ethyl-4-ethylamino-3,5-diphenyl- 1,2,4 triazolium ethyl sulphate 11.4% weight/volume water to 100% Example 111.

A 5% aqueous concentrate of 1 -ethyl-4-methylamino-3 ,5-di(m-tolyl)-l ,2,4- triazolium cation was prepared by admixing the following: I -ethyl-4-methylamino-3,5-di(m-tolyl)- 1,2,4-triazolium ethyl sulphate 7 weight/volume water to 1000/, Example 112.

A buffered 4.8% aqueous concentrate of l-ethyl-4-methylamino-3,5-di(rn- tolyl)-l,2,4-triazolium cation was prepared by admixing the following: 1 -ethyl-4-methylamino-3,5-di(m-tolyl)- 1,2,4 triazolium ethyl sulphate 6.7% weight/volume anhydrous sodium acetate 1.0% weight/volume water to 100% Example 113.

A 10% aqueous alcoholic concentrate of 1-methyl-4-methlamino-3,5-dipentyl- 1,2,4-triazolium cation was prepared by admixing the following: I -methyl-4-methylamino-3,5-dipentyl- 1,2,4 triazolium methyl sulphate 14.4% weight/volume I-molar sodium hydroxide solution to pH 7 approx. 3.6% by volume 2-ethoxyethanol 5% by volume n-butanol to 100% Example 114.

A 10% aqueous alcoholic concentrate of 1-ethyl-4-methyl mino-3,5-dipentyl- 1,2,4-triazolium cation was prepared by admixing the following: I -ethyl-4-methylamino-3,5-dipentyl- 1,2,4- triazolium ethyl sulphate 14.7% weight/volume l-molar sodium hydroxide solution, to pH 5 approx. 1.25% by volume n-butanol to 100% Examples 115-127.

Seeds of peas (Pisum sativum), mustard (Sinapis alba), linseed (Linum usitatissimum), ryegrass (Lolium sp), oats (Avena sativa), sugar beet (Beta vulgaris) and French beans (Phaseolus vulgaris) were sown in anodised aluminium pans, 19 cm long x 9.5 cm wide x 5 cm deep containing John Innes I potting compost. They were then watered and placed in a controlled environment room (temperature 22"C, relative humidity 6585%, artificial illumination 13,000 lux for 14 hours per day). After 14 days, the seedlings were sprayed with aqueous solutions or suspensions of the compounds listed below at rates equivalent to 11.2 and 2.8 kg of active ingredient cation in 450 litres per hectare.

After 7 days growth in the controlled environment room, the plants were visually assessed for any herbicidal or growth regulant response, all differences from untreated controls being scored on a 0 to 100 scale in which 0 signifies no effect and 100 signifies complete kill. The results are tabulated below: Rate Herbicidal Effect Compound Kg/ha Peas Mustard Linseed Ryegrass Oats Sugarbeet Beans 1-methyl-3,5-dicyclohexyl-4-amino- 11.2 30 70 30 60 60 20 30 1,2,4-traizolium methyl sulphate 1-methyl-3,5-dicyclohexyl-4-methyl- 11.2 40 40 80 60 80 40 60 amino-1,2,4-triazolium methyl sulphate 2.8 30 20 30 10 60 30 20 1-methyl-3,5-dipentyl-4-amino-1,2,4- 11.2 60 70 100 30 90 100 90 triazolium methyl sulphate 2.8 20 40 30 20 80 30 30 1-methyl-3,5-dipentyl-4-methylamino- 11.2 90 100 100 70 100 100 90 1,2,4-triazolium methyl sulphate 2.8 60 70 70 30 80 40 70 1-methyl-3,5-dipentyl-4-ethylamino- 11.2 100 100 100 70 90 100 90 1,2,4-triazolium methyl sulphate 2.8 70 40 100 20 70 30 90 1-ethyl-3,5-dipentyl-4-methylamino- 11.2 90 100 100 100 90 100 100 1,2,4-triazolium ethyl sulphate 2.8 70 80 80 20 60 80 70 1-methyl-3,5-di(3-methylbutyl)-4- 11.2 70 60 90 70 90 100 60 amino-1,2,4-triazolium methyl sulphate 2.8 20 20 30 10 70 20 20 1-ethyl-3,5-dibutyl-4-methylamino- 11.2 80 90 100 70 90 100 40 1,2,4-triazolium ethyl sulphate 2.8 30 20 50 10 70 30 10 1-methyl-3,5-dibutyl-4-ethylamino- 11.2 70 80 100 40 90 100 70 1,2,4-triazolium methyl sulphate 2.8 10 20 20 5 60 10 30 1-ethyl-3,5-dibutyl-4-ethylamino- 11.2 70 90 100 90 100 100 90 1,2,4-triazolium ethyl sulphate 2.8 30 80 90 30 90 90 70 1-ethyl-3,5-di(3-methylbutyl)-4- 11.2 70 80 90 20 80 80 80 amino-1,2,4-triazolium ethyl sulphate 2.8 20 20 30 10 60 30 40 1-methyl-3,5-dicyclopentyl-4-amino- 11.2 20 5 30 0 60 30 30 1,2,4-triazolium methyl sulphate 2.8 0 0 10 0 40 10 10 1-methyl-3,5-di(3-cyclohexen-1-yl)-4- 11.2 20 70 60 40 80 60 60 methylamino-1,2,4-triazolium methyl sulphate 2.8 10 40 20 20 60 20 20 Examples 128-135.

The potentiating effect of surface active agents was tested as follows. Wild oat (Avena fatua) seeds were sown in 10 cm pots containing sterilised loam in a greenhouse. When the plants had grown to the 2±3 leaf stage, they were sprayed at 200 litres per hectare with an aqueous spray containing the compound 1-ethyl 3,5-diphenyl-4-methylamino-1,2,4-triazolium ethyl sulphate such that I or 2 kg of its cation were applied per hectare. Analogous sprays were applied containing, besides the compounds, the following surface active agents: Lissapol N, 25% of nonyl phenol condensed with 8 moles of ethylene oxide; Tergitol TMN, trimethyl nonanol condensed with 6 moles of ethylene oxide; X-77, alkyl aryl polyoxyethylene glycol plus free fatty acids in iso propanol; Genapol X080, isotridecyl alcohol condensed with 8 moles of ethylene oxide; Sapogenat T1 10, tributyl phenol condensed with 11 moles of ethylene oxide; Tergitol NPX, nonyl phenol condensed with 10t moles of ethylene oxide; or Pluronic L61, ethylene oxide -- propylene oxide block copolymer containing 10% by weight ethylene oxide units, molecular weight 2,000.

The amount of the surface active agent in the spray volume was 0.5 or 1% except for Tergirol TMN, where the content was 0.1 or 0.5%.

Three replicates were carried out for each treatment.

The plants were assessed visually for percentage chemical effect/growth reduction compared with control plants 1+, 3, 5, 7 and 9 weeks after treatment.

The mean results are shown in the following Table:

Weeks after treatment 1 3 5 7 9 Rate, kg cation/ha 1 2 1 2 1 2 1 2 1 2 Wetting Agent, % * 0.5 1 0.5 1 0.5 1 0.5 1 0.5 1 0.5 1 0.5 1 0.5 1 0.5 1 0.5 1 Lissapol N 20 25 15 40 47 58 52 66 63 71 68 75 66 71 73 79 60 70 77 77 % 0.1 0.5 0.1 0.5 0.1 0.5 0.1 0.5 0.1 0.5 0.1 0.5 0.1 0.5 0.1 0.5 0.1 0.5 0.1 0.5 Tergitol TMN 10 15 15 40 45 59 49 64 53 60 64 68 48 60 76 76 48 58 78 75 X-77 10 20 15 25 59 63 63 67 66 71 70 73 52 70 73 80 54 73 73 80 Genapol XO80 10 40 50 35 59 73 74 71 60 75 77 77 66 74 79 81 62 70 76 84 Sapogenat T110 20 25 25 35 61 64 57 76 65 68 69 77 58 77 79 79 60 74 79 77 Tergitol NPX 15 15 15 50 53 58 54 67 68 70 67 75 63 71 67 77 58 70 67 80 Pluronic L61 7 10 20 20 39 49 58 67 54 61 73 70 47 52 67 65 35 48 63 60 * Except where stated.

Examples 136-143.

Safety to Maris Huntsman winter wheat (Triticum vulgare) was assessed in tests analogous to those described in Examples 75-82 except that assessment was 1, 3, 5 and 7 weeks after treatment, this winter wheat being the plant tested an the treatments being carried out at the 2 leaf stage. For comparison, difenzoquat was also tested, applying 1 or 2 kg per hectare of its cation, the material being employed as the aqueous solution of the methyl sulphate containing 250 g of cation per litre sold under the name Avenge 250 W.

The mean percentage growth reduction/chemical effect is shown in the following Table:

Weeks after Treatment 1 3 Chemical Present Compound Difenzoquat Present Compound Difenzoquat Rate, kg cation/ha 1 2 1 2 1 2 1 2 Wetting Agent added, %* 0.5 1 0.5 1 - - 0.5 1 0.5 1 - Lissapol N 2 10 8 15 12 14 12 15 % 0.1 0.5 0.1 0.5 0.1 0.5 0.1 0.5 Tergitol TMN 0 0 5 10 3 8 11 13 X-77 7 0 10 10 6 8 16 20 Genapol XO80 7 7 10 5 8 11 8 11 Sapogenat T110 4 4 5 15 8 11 17 28 Tergitol NPX 3 1 5 7 4 7 11 15 Pluronic L61 4 0 0 2 8 12 10 12 None 0 1 20 30 2 3 28 42 * except where stated

Weeks after Treatment 5 7 Chemical Present Compound Difenzoquat Present Compound Difenzoquat Rate, kg cation/ha 1 2 1 2 1 2 1 2 Wetting Agent added, %* 0.5 1 0.5 1 - - 0.5 1 0.5 1 - Lissapol N 8 10 11 15 5 10 10 16 % 0.1 0.5 0.1 0.5 0.1 0.5 0.1 0.5 Tergitol TMN 4 10 10 12 8 11 6 13 X-77 3 9 14 17 8 11 14 20 Genapol XO80 8 12 11 14 9 10 9 12 Sapogenat T110 11 14 14 27 11 12 15 20 Tergitol NPX 7 9 7 11 8 9 10 13 Pluronic L61 8 14 11 14 9 15 8 12 None 0 0 35 47 0 0 37 43 * except where stated It can be seen that the present compound, I-ethyl-3,5-diphenyl-4 methylamino-l,2,4-triazolium ethyl sulphate, is much safer than difenzoquat to Maris Huntsman wheat.

Example 144.

1,4-Dimethyl-3,5-diphenyl-1,2,4-triazolium methyl sulphate (a) 3,5-Diphenyl- I-methyl-I ,2,4-triazole 23.6 g of 4-amino-3,5-diphenyl-1,2,4-triazole was heated at 2000C for 10 minutes with 12.6 g of dimethyl sulphate. The resulting hot oil was dissolved in 70 ml of 5% hydrochloric acid. The solution was cooled to 50C and a 10% solution of sodium nitrite added dropwise with stirring, keeping the temperature at 50C. This was continued until the mixture gave a positive colour with starch iodide paper.

The sticky mixture was neutralised with 40% sodium hydroxide solution and extracted with 3 x 150 ml of ether. The combined ether solutions were dried over magnesium sulphate and evaporated down to a solid. This was then recrystallised from 500 ml of 40-60 C petroleum ether to yield 11.4 g (48%) of 3,5-diphenyl-l methyl-i ,2,4-triazole, m.p. 80--840C.

* (b) 1 ,4-Dimethyl-3,5-diphenyl- 1 ,2,4-triazolium methyl sulphate 4.7 g of 3,5-diphenyl-1-methyl-1,2,4-triazole and 2.5 g of dimethyl sulphate were heated together at 160-170 C for 20 minutes. The product was poured out hot and when cooled it solidified to a solid which was washed with ether and dried to give 6.6 g (92%) of 1,4-dimethyl-3,5-diphenyl-1,2,4-triazolium methyl sulphate, m.p. 42480C.

Analysis: C H N Calculated 56.46 5.30 11.62% Found 56.31 5.45 11.23% The following compounds were prepared by analogous techniques.

Example 145.

1,4-Dimethyl-3,5-di-(p-tolyl)-1,2,4-triazolium methyl sulphate, m.p. 53"C.

Analysis C H N Calculated 58.59 5.95 10.79% Found 58.09 5.80 10.62% Example 146.

3,5-Di-(p-chlorophenyl)-1-ethyl-4-methyl-1,2,4-triazolium methyl sulphate.

Analysis: C H N Calculated 48.65 4.31 9.46% Found 48.37 4.42 9.45% Example 147..

3.5-Diphenyl-l-ethyl-4-methyl-l ,2,4-triazolium methyl sulphate.

Analysis C H N Calculated 57.58 5.64 11.19% Found 57.25 5.75 11.22% Example 148.

3,5-Di-(m-tolyl)-l ,4-dimethyl-l ,2,4-triazolium methyl sulphate.

Analysis: C H N Calculated 58.59 5.95 10.79% Found 58.11 5.81 10.45% Example 149.

3,5-Di-(m-tolyl)-4-ethyl-1-methyl-1,2,4-triazolium methyl sulphate.

Analysis: C H N Calculated 60.41 6.52 10.06% Found 59.92 6.25 10.20% Example 150.

1,3-Diphenyl-4,5-diethyl-1,2,4-triazolium ethyl sulphate.

Analysis: C H N Calculated 59.93 6.24 10.41% Found 59.21 6.42 10.45% Example 151.

1,3-Diphenyl-5-ethyl-4-methyl-1,2,4-triazolium methyl sulphate, m.p. 120"C.

Analysis: C H N Calculated 57.58 5.64 11.19% Found 57.54 5.88 11.47% Example 152.

1,3-Diphenyl-4,5-dimethyl-1,2,4-triazolium methyl sulphate, m.p. 185-190 C.

Analysis: C H N Calculated 56.49 5.30 11.63% Found 56.31 5.00 11.47% Example 153.

1 -methyl-3,4,5-triphenyl- 1,2,4-triazolium methyl sulphate, m.p. 84--860C.

Analysis: C H N Calculated 62.39 5.00 9.92% Found 61.95 5.00 9.93% Example 154.

1,3-Diphenyl-4,5-ethyl-5-methyl-1,2,4-triazolium ethyl sulphate, m.p.

104-106 C.

Analysis: C H N Calculated 58.59 5.95 10.79% Found 58.51 5.60 11.05% Example 155.

1-Phenyl-3-(p-tolyl)-4,5-dimethyl-1,2,4-triazolium ethyl sulphate.

Analysis: C H N Calculated 57.58 5.64 11.19% Found 57.41 5.68 11.43% Example 156.

I ,4-dimethyl-3,5-di-n-pentyl- I 2,4-triazolium methylsulphate, oil.

Example 157.

1 -methyl-3,5-di-n-pentyl-4-ethyl- 1,2,4-triazolium ethylsulphate, oil.

Example 158.

Seeds of peas, mustard, linseed, ryegrass, sugarbeet, wild and cultivated oats, wheat and barley were sown in anodised aluminium pans, 19 cm long x 9.5 cm wide x 5 cm deep containing John Innes I potting compost. They were then watered and placed in a controlled environment-room (22"C; 6585% RH; 14 hours artificial illumination at 1,200 foot candles). Fourteen days after sowing the seedlings received a foliar spray of the compound of Example 144 formulated as a 50% aqueous acetone solution. The concentration of active ingredient and volume of application were adjusted so as to be equivalent to rates of 11.2 and 2.8 kg/ha in 450 litres per hectare.

After seven days growth in a controlled environment room the plants were visually assessed for any herbicidal or growth regulant response. All differences from the untreated control were scored according to a herbicidal index where 0 no effect and 100 = complete kill.

The results are summarised in the following table:

Species Dosage rate kg/ha 11.2 2.8 Peas - Pisum sativum 50 15 Mustard - Sinapis alba 10 5 Linseed - Linum usitatissimum 65 34 Ryegrass - </RT from the untreated control were scored according to a herbicidal index where 0 no effect and 100 = complete kill.

The results are summarised in the following table:

Species Dosage rate kg/ha 11.2 2.8 Peas - Pisum sativum 50 20 Mustard - Sinapis alba 75 50 Linseed - Linum usitatissimum 90 40 Ryegrass - Lolium perenne 75 20 Sugarbeet - -Beta vulgaris 94 60 Oat - Avena sativa 80 55 Wild Oat - Avenafatua 80 60 Barley - Hordeum vulgare 20 0 Wheat - Triticum aestivum 15 0 Example 160.

Seeds of peas, mustard, linseed, ryegrass, sugarbeet, wild and cultivated oats, barley and wheat were sown in anodised aluminium pans, 19 cm long x 9.5 cm wide x 5 cm deep containing John Innes I potting compost. They were then watered and placed in a controlled environment room (22"C; 6585% RH; 14 hours artificial illumination at 1,200 foot candles). Fourteen days after sowing the seedlings received a foliar spray of the compound of Example 152 formulated as a 50% aqueous acetone solution. The concentrations of active ingredient-and volume of application were adjusted so as to be equivalent to rates of 11.2 and 2.8 kg/ha in 450 litres per hectare.

After seven days growth in a controlled environment room the plants were visually assessed for any herbicidal index where 0 = no effect and 100 = complete kill.

The results are summarised in the following table:

Species Do-sage rate kg/ha 11.2 2.8 Peas - Pisum sativum 20 5 Mustard - Sinapis alba 20 10 Linseed - Linum usitatissimum 35 10 Ryegrass - Lolium perenne 10 0 Sugarbeet - Beta vulgaris 85 60 Oat - -Avena sativa 75 40 Wild Oat - Avena fatua 80 50 Barley - Hordeum vulgare 10 0 Wheat - Triticum aestivum 5 0 Example 161.

Seeds of various monocotyledon species, listed in the table below were sown in anodised aluminium pans 19 cm long x 9.5 cm wide x 5.0 cm deep, containing John Innes I potting compost. They were then watered and placed in a controlled environment room (22 C; 65-85% RH; 14 hours artificial illumination at 1,600 foot candles). Fourteen days after sowing the seedlings were given a foliar spray of the compound of Example 152 formulated as aqueous acetone solution together with 1,000 ppm of the wetting agent Lissapol NX. The dosage rate was adjusted to be 2.8 kg active ingredient in 450 litres/hectare.

After a further 14 days in the controlled environment room the plants were visually assessed for any growth regulatory or herbicidal effect. All differences from an untreated control were scored on a scale 0100 where 0 signifies no effect and 100 signifies complete suppression.

The results are summarised in the following table:

Species Dosage rate kg/ha 2.8 Wheat - Triticum aestivum 5 Barley - Hordeum vulgare 5 Wild oat - Avena fatua 74 Blackgrass - Alopecurus myosuroides 34 Barnyardgrass - Echinochloa crus-galli 5 Crabgrass - Digitaria sanguinalis 50 Example 162.

Seeds of peas, mustard, linseed, ryegrass, sugarbeet, wild and cultivated oats, barley and wheat were sown in anodised aluminium pans, 19 cm long x 9.5 cm wide x 5 cm deep containing John Innes I potting compost. They were then watered and placed in a controlled environment room (22 C: 65-85% RH; 14 hours artificial illumination at 1,200 foot candles). Fourteen days after sowing the seedlings received a foliar spray of the compound of Example 155 formulated as a 50% aqueous acetone solution. The concentrations of active ingredient and volume of application were adjusted so as to be equivalent to rates of 11.2 and 2.8 kg/ha in 450 litres per hectare.

After seven days growth in a controlled environment room the plants were visually assessed for any herbicidal or growth regulant response. All differences from the untreated control were scored according to a herbicidal index where 0 = no effect and 100 = complete kill.

The results are summarised in the following table:

Species Dosage rate kg,'ha 11.2 2.8 Peas - Pisum sativum 75 30 Mustard - Sinapis alba 75 30 Linseed - Linum usitatissimum 95 75 Ryegrass - Lolium perenne 50 15 Sugarbeet - Beta vulgaris 85 60 Oat - Avena sativa 70 55 Wild Oat - Avena fatua 70 60 Barley - Hordeum vulgare 15 0 Wheat - Triticum aestivum 20 5 Example 163. a,a'-Dichlorobenzalazine (55 parts) and unsymmetrical dimethylhydrazine (36 parts) were heated in refluxing ethanol (250 parts) for 10 hours. The solution was evaporated to dryness. The residue was then washed with water and the solid filtered off and dried to yield 4-dimethylamino-3,5-diphenyl- 1,2,4-triazole (45 parts), m.p. 218"C.

Analysis: C H N Calculated 72.70 6.10 21.20 Found 72.63 6.25 21.37 On reaction with dimethyl sulphate as described in Example 1, 4 dimethylamino- 1 -methyl-3,5-diphenyl 1 ,2,4-triazolium methylsulphate, m.p.

159"C, was obtained.

Analysis: C H N Calculated 55.37 5.68 14.35% Found 54.94 5.68 13.94% Example 164.

4-Amino-3,5-di-rn-tolyl-l,2,4-triazole (19.8 parts) and acetone (47.5 parts) plus 5 drops of acetic acid were heated at 2000C for 24 hours in a Carius tube. After evaporation of the excess acetone and recrystallisation from ethanol, 19.3 parts of 4-isopropylideneamino-3,5-di-m-tolyl-1,2,4-triazole, m.p. 143--145"C were obtained.

Analysis C H N Calculated 74.97 6.62 18.41% Found 75.14 7.03 18.36% This material is converted by reaction with methylsulphate and ethylsulphate respectively into the corresponding l-methyl and l-ethyl triazolium salts by procedures as described in Example 1.

Example 165.

3,5-Diphenyl-4-isopropylideneamino-1,2,4-triazole (17.3 parts), prepared by a method analogous to that of Example 164, was dissolved in methanol (150 parts) containing 0.3 parts of sodium. Sodium borohydride (2.9 parts) were added, and the reaction mixture was refluxed for 2 hours. After dilution with water, filtration, and recrystallisation from ethanol, 12.0 parts of 4-isopropylamine-3,5-diphenyl-1,2,4triazole were obtained, m.p. 221--223"C.

Analysis: C H N Calculated 73.35 6.52 20.13% Found 73.47 6.61 19.88% This material is converted by reaction with methylsulphate and ethylsulphate respectively into the corresponding l-methyl and methyl triazolium salts by procedures as described in Example 1.

Examples 166-192.

Aqueous acetone suspensions of the compounds of the Examples listed below, containing 500 ppm (wt/vol) of active ingredients together with 125 ppm of a nonionic wetting agent were applied to the leaves of young barley plants having two fully developed leaves. The treated plants, together with controls treated only with aqueous acetone containing the wetting agent, were inoculated 24 hours after the chemical application with spores of the disease organism known as barley powdery mildew, Erisiphe graminis. They were then placed in a water saturated atmosphere for 24 hours and 80-90% R.H.) until disease incidence was assessed 14 days later.

The % disease control for the treatments were: Compound of % Disease Example No. Control 35 78 42 92 43 80 44 100 45 100 46 100 47 78 48 70 49 80 50 92 51 94 52 90 53 88 54 68 55 82 56 100 57 94 58 80 59 94 60 98 61 92 62 100 63 94 64 100 65 82 156 72 157 90 Control 0

Claims

WHAT WE CLAIM IS:-

1. A method of combating pests at a locus infested or liable to be infested with them or of regulating the growth of a desired plant at a locus at which the plant is growing or is to grow, which method comprises applying to the locus a pestcombating or a plant growth regulant amount of a compound which is a 1,2,4triazolium salt of formula

in which R represents a substituted or unsubstituted alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, aryl, aralkyl, or heterocyclic group; R2 and R4 are the same or different and each represents a hydrogen atom or a substituted or unsubstituted alkylthio, arylthio, or aralkylthio group or a group as defined for R1; R3 represents a group as defined for R' or the group R5-N-R6 where R6 represents a hydrogen atom or a substituted or unsubstituted alkyl, cycloalkyl, alkenyl, alkynyl, aralkyl or aryl group; Re represents a hydrogen atom; -SO2R7 or

where A represents an oxygen or sulphur atom, Z represents a single bond, an oxygen or sulphur atom or an -NR8 group, R7 represents a substituted or unsubstituted alkyl, aryl or aralkyl group and R8 represents a hydrogen atom or a group as defined for R7; or a substituted or unsubstituted alkyl, cycloalkyl, alkenyl, aralkyl or aryl group; or R5 and R6 together represent a group of formula =CR9R10 where R9 and R10 are the same of different and each represent a hydrogen atom or a substituted or unsubstituted alkyl, aryl or aralkyl group, or R9 and R10 together represent an alkylene chain; R" represents a group -SO2R7 or

wherein A, Z and R7 are a defined above, and Xo represents one equivalent of an anion.

2. A method according to claim 1 wherein R' represents an alkyl of 1--6 carbon atoms, alkenyl of 26 carbon atoms, alkynyl of 26 carbon atoms, cycloalkyl of 3-7 carbon atoms, cycloalkenyl of 3-7 carbon atoms, phenyl, phenylalkyl of 7-10 carbon atoms, furyl, pyranyl, pyrrolyl, pyridyl, quaternised pyridyl,. or thienyl group, which group is unsubstituted or substituted by one or more substituents selected from halogen, hydroxy, mercapto, alkoxy of 16 carbon atoms, alkylthio of 1-6 carbon atoms, alkylsulphonyl of 1-6 carbon atoms, alkylsulphinyl of 1-6 carbon atoms, alkanoyl of 1-7 carbon atoms, nitro, cyano, carboxy, esterified, salified or amidated carboxy, amino, amino substituted by 1 or 2 alkyl groups of 1-6 carbon atoms, and, except where R' represents substituted alkyl, alkyl of 16 carbon atoms; R2 and R4 are the same or different and each represents a hydrogen atom or an alkyl of 1-15 carbon atoms, alkylthio of 1-15 carbon atoms, alkenyl of 2-6 carbon atoms, alkynyl of 26 carbon atoms, cycloalkyl of 3-7 carbon atoms, phenyl, phenylthio, phenylalkyl of 7-10 carbon atoms, phenylalkylthio of 7-10 carbon atoms, furyl, pyranyl, pyrrolyl, pyridyl, quaternised pyridyl, or thienyl group, which group is unsubstituted or substituted by one or more substituents selected from halogen, hydroxy, mercapto, alkoxy of 1-6 carbon atoms, alkylthio of 16 carbon atoms, alkylsulphonyl of 16 carbon atoms, alkylsulphinyl of 1-6 carbon atoms, alkanoyl of 1-7 carbon atoms, nitro, carboxy, esterified, salified or amidated carboxy, amino, amino substituted by 1 or 2 alkyl groups of 1-15 carbon atoms, alkenyl or alkynyl of 2-6 carbon atoms, cycloalkyl of 3-7 carbon atoms and except when it represents substituted alkyl, alkyl of 1-6 carbon atoms; R3 represents a group as defined for R' or the group R5-N-R6 where Re represents a hydrogen atom or an alkyl of 1-15 carbon atoms, alkenyl of 2-6 carbon atoms, alkynyl of 26 carbon atoms, cycloalkyl of 3-7 carbon atoms, phenylalkyl of 7-10 carbon atoms or phenyl group, which group is unsubstituted or substituted by one or more substituents selected from halogen, alkoxy of 1-6 carbon atoms, nitro and, except when Re represents a substituted alkyl group, alkyl of 16 carbon atoms; R5 represents a hydrogen atom; -SO2R7 or

where A represents an oxygen or sulphur atom, Z represents a single bond, an oxygen or sulphur atom or an -NR8 group, R7 represents alkyl of 1-6 carbon atoms, phenyl or phenylalkyl of 7-10 carbon atoms and R8 represents a hydrogen atom or a group as defined for R7; or an alkyl of 1-6 carbon atoms, alkenyl of 2-6 carbon atoms, alkynyl of 2-6 carbon atoms, cycloalkyl of 3-7 carbon atoms, phenylalkyl of 7-10 carbon atoms or phenyl group, which group is unsubstituted or substituted by one or more substituents selected from halogen, alkoxy of 1-6 carbon atoms, nitro and, except when R5 represents a substituted alkyl group, alkyl of 1-6 carbon atoms; or Re or Re together represent a group of formula =CR9R'0 where R9 and R10 are the same or different and each represent a hydrogen atom or an alkyl of 1-6 carbon atoms, phenyl or phenylalkyl of 7-10 carbon atoms group, which group is unsubstituted or substituted by one or more substituents selected from halogen, alkoxy of 1-6 carbon atoms, nitro and, except when it represents a substituted alkyl group, alkyl of 1-6 carbon atoms, or together represent an alkylene chain of 3-7 carbon atoms, and R11 represents a group -SO2R7 or

as defined herein.

3. A method according to claim 1, wherein the compound is of formula II or of formula I where R3 represents the group R5-N-R0.

4. A method according to claim 3 wherein R' represents a substituted or unsubstituted alkyl, aryl or aralkyl group; and R2 and R4 are the same or different and each represents a hydrogen atom or a substituted or unsubstituted alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, aryl, aralkyl or alkylthio group.

5. A method according to claim 4 wherein R2 and R4 are the same or different and each represents a hydrogen atom or a substituted or unsubstituted alkyl, aryl, aralkyl or alkylthio group.

6. A method according to claim 5 wherein the compound is of formula I in which R' represents alkyl, R2 and R4 each represent aryl, each represent alkyl or each represent aryl monosubstituted by alkyl, RE represents a hydrogen atom and Re represents alkyl.

7. A method according to claim 1 wherein the compound is of formula I where R3 represents a group as defined for R'.

8. A method according to claim 7 wherein the pests are weeds, and R1 and R3 are the same or different and each represents a substituted or unsubstituted alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, aryl, aralkyl or aromatic heterocyclic group.

9. A method according to any one of the preceding claims wherein Xe represents chloride, bromide, iodide, acetate, hydroxide, sulphate, hydrogen sulphate, alkyl sulphate, p-toluene sulphonate, perchlorate or alkyl sulphonate.

10. A method according to claim 1 wherein R', R2, Ra, R4, RE, Re, A, Z, R', R8, R', R'O and R11 have any one of the meanings they have in the compounds of formula I or II which are specified herein.

11. A method according to claim 10 wherein the cation of the compound is the cation of a compound of formula I or II which is specified herein.

12. A method according to claim 10 wherein the compound is a compound of formula I or II which is specified herein.

13. A method according to claim 1 wherein the compound is a 4-methylamino I-ethyl-3,5-diphenyl- 1,2,4-triazolium salt.

14. A method according to claim 1 wherein the compound is a 4-methylamino I -ethyl-3 ,5-di(3-methylbutyl)- I ,2,4-triazolium salt.

15. A method according to claim 1 wherein the compound is a 4-methylamino l-ethyl-3,5-dipentyl-l 2,4-triazolium salt.

16. A method according to any one of claims 13-15 wherein the salt is the chloride or ethyl sulphate.

17. A method according to claim 1 wherein the compound is a 4-amino-l- methy13,5 -di(3-methylbutyl)- 1,2,4-triazolium salt.

18. A method according to claim 1 whe'rein the compound is a 4-amino-l- methyl-3,5-dipentyl- 1,2,4-triazolium salt.

19. A method according to claim 1 wherein the compound is a 4-methylamino I -methyl-3 ,5-diphenyl- 1 2,4-triazolium salt.

20. A method according to claim 1 wherein the compound is a 4-methylamino 1-ethyl-3,5-di-(3-methylbutyl)-1,2,4-triazolium salt.

21. A method according to claim 1 wherein the compound is a 4-methylamino I-n-propyl-3 ,5-di-n-butyl-l ,2,4-triazolium salt.

22. A method according to claim 1 wherein the compound is a 4-methylamino I-n-pentyl-3 ,5-di-n-butyl-l ,2,4-triazolium salt.

23. A method according to claim 1 wherein the compound is a 4-methylamino 1 ,3,5-tri-n-butyl- I ,2,4-triazolium salt.

24. A method according to claim 1 wherein the compound is a 4-ethylamino 1,3 ,5-tri-n-butyl- 1 ,2,4-triazolium salt.

25. A method according to claim 1 wherein the compound is a 4-ethylamino- 1 - (3-methylbutyl)-3 , 5-di-n-butyl- 1 2,4-triazolium salt.

26. A method according to claim 1 wherein the compound is a4-ethylatpino-l- isobutyl-3,5-di-n-butyl-l ,2,4-triazolium salt.

27. A method according to claim 1 wherein the compound is a 4-n-pentylamino-l -(3-methylbutyl)-3,5-diethyl-l ,2,4-triazolium salt.

28. A method according to claim I wherein the compound is a 4-methylamino I-allyl-3,5-di(3-methylbutyl)-1,2,4-triazolium salt.

29. A method according to claim I wherein the compound is a 4-n-propylamino- 1 -n-hexyl-3,5-diethyl- 1,2,4-triazolium salt,

30. A method according to claim I wherein the compound Is a 4-npentylamino- I -n-butyl-3 ,5-diethyl- 1,2,4-triazolium salt.

31. A method according to any one of claims 17-30 wherein the salt is the chloride, bromide or methyl sulphate.

32. A method according to any one of the preceding claims wherein weeds are selectively combated in a crop.

33. A method according to claim 32 wherein the crop is a cereal crop.

34. A method according to claim 32 or 33 wherein 0.5-10 kg of the compound are applied per hectare.

35. A method according to claim I performed substantially as herein before described.

36. A method according to claim I performed substantially as hereinbefore described in any one of Examples 67 to 143, 158 to 162 and 166-192.

37. A compound of formula

in which R' represents a substituted or unsubstituted alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, aralkyl, or heterocyclic group; R2 and R4 are the same or different and each represents a substituted or unsubstituted alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, aryl, aralkyl, alkylthio of more than I carbon atom, arylthio, aralkylthio or heterocyclic group; with the proviso that R2 an R4 do not both represent methyl; R3 represents the group R6~NRe where Re represents a hydrogen atom or a substituted or unsubstituted alkyl or aralkyl group; RE represents a hydrogen atom; -SO2R' or

where A represent an oxygen or sulphur atom, Z represents a single bond, an oxygen or sulphur atom or an -NR8 group, R7 represents a substituted or unsubstituted alkyl, aryl or aralkyl group and R8 represents a hydrogen atom or a group as defined for R7; or a substituted or unsubstituted alkyl, cycloalkyl; alkenyl, alkynyl, aralkyl or aryl group; or RE and Re together represent a group of formula =CR9R'0 where RB and R'O are the same or different and each represent a hydrogen atom or a substituted or unsubstituted alkyl, aryl or aralkyl group, or R9 and R10 together represent an alkylene chain; R11 represents a group -SO2R7 or

X- represents one equivalent of an anion; with the proviso that when R represents methyl, R and R4 represent phenyl and X- represents bromide or iodide then R does not represent amino.

38. A compound of formula

in which R' represent a substituted or unsubstituted alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, aryl, aralkyl or heterocyclic group; R2 and R4 are the same or different and each represents a hydrogen atom or a substituted or unsubstituted alkylthio, arylthio, or aralkylthio group, or a group as defined for R'; R3 represents a group R5-N-R6 where Re represents a hydrogen atom or a substituted or unsubstituted alkyl, cycloalkyl, alkenyl, alkynyl, aralkyl or aryl group; R5 represents a hydrogen arom; -SO2R7 or

where A represents an oxygen or sulphur atom, Z represents a single bond, an oxygen or sulphur atom or an - NR8 group, R7 represents a substituted or unsubstituted alkyl, aryl or aralkyl group and Re represents a hydrogen atom or a group as defined for R7; or a substituted or unsubstituted alkyl, cycloalkyl, alkenyl, alkynyl, or aryl group; or R5 and R6 together represent a group of formula =CR9R10 were R9 and R10 are the same or different and each represent a hydrogen atom or a substituted or unsubtituted alkyl, aryl or aralkyl group, or R9 and R10 together represent an alkylene chain; and Xe represents alkyl sulphate, with the exception of that compound wherein X- represents methyl sulphate, R represents methyl, R and R4 each represent a hydrogen atom and R5 and R6 together represent

H =C-phenyl.

39. A compound according to claim 37 wherein R represent an alkyl of 1-6 carbon atoms, alkenyl of 2-6 carbon atoms, alkynyl of 2-6 carbon atoms, cycloalkyl of 3-7 carbon atoms, cycloalkenyl of 3-7 carbon atoms, phenyl, phenylalkyl of 7-10 carbon atoms, furyl, pyranyl, pyrrolyl, pyridyl, quaternised pyridyl, or thienyl group, which group is unsubstituted or substituted by one or more substituents selected from halogen, hydroxy, mercapto, alkoxy of 16 carbon atoms, alkylthio of 1--6 carbon atoms, alkylsulphonyl of 16 carbon atoms, alkylsulphinyl of 1--6 carbon atoms, alkanoyl of 1--7 carbon atoms, nitro, cyano, carboxy, esterified, salified or amidated carboxy, amino, amino substituted by I or 2 alkyl groups of 1--6 carbon atoms, and, except where R represents substituted alkyl, alkyl of 1-6 carbon atoms; R and R4 are the same of different and each represents an alkyl of 1-15 carbon atoms, alkylthio of 2-15 carbon atoms, alkenyl of 2-6 carbon atoms, alkynyl of 26 carbon atoms, cycloalkyl of 3-7 carbon atoms, phenyl, phenylthio, phenylalkyl of 7-10 carbon atoms, phenylalkylthio of 7-10 carbon atoms, furyl, pyranyl, pyrrolyl, pyridyl, quaternised pyridyl, or thienyl group, which group is unsubstituted or substituted by one or more substituents selected from halogen, hydroxy, mercapto, alkoxy of 1-6 carbon atoms, alkylthio of 16 carbon atoms, alkylsulphonyl of 1-6 carbon atoms, alkylsulphinyl of 16 carbon atoms, alkanoyl of 1-7 carbon atoms, nitro, cyano, carboxy, esterified, salified or amidated carboxy, amino, amino substituted by 1 or 2 alkly groups of 1-15 carbon atoms, alkenyl or alkynyl or 26 carbon atoms, cycloalkyl of 3-7 carbon atoms, and, except when it represents substituted alkyl, alkyl of 1-6 carbon atoms; R3 represents the group R5-N-R6 where R6 represents a hydrogen atom or an alkyl of I-IS carbon atoms, or phenylalkyl of 7-10 carbon atoms, group, which group is unsubstituted or substituted by one or more substituents selected from halogen, alkoxy of 1-6 carbon atoms, nitro and, except when Re represents a substituted alkyl group, alkyl of 16 carbon atoms; Re represents a hydrogen atom; -SO2R7 or

where A represents an oxygen or sulphur atom, Z represents a single bond, - an oxygen or sulphur atom or an NRC group, R7 represents alkyl of 16 carbon atoms, phenyl or phenylalkyl of 7-10 carbon atoms and Re represents a hydrogen atom or a group as defined for R7; or an alkyl of 16 carbon atoms, alkenyl of 26 carbon atoms, alkynyl of 26 carbon atoms, cycloalkyl of 3-7 carbon atoms, phenylalkyl of 7-10 carbon atoms or phenyl group, which group is unsubstituted or substituted by one or more substituents selected from halogen, alkoxy of 16 carbon atoms, nitro and, except when R5 represents a substituted alkyl group, alkyl of 16 carbon atoms; or R5 and Re together represent a group of formula =CR9R10 where R9 and R10 are the same or different and each represent a hydrogen atom or an alkyl of 1-6 carbon atoms, phenyl or phenylalkyl of 7-10 carbon atoms group, which group is unsubstituted or substituted by one or more substituents selected from halogen, alkoxy of 1-6 carbon atoms, nitro and, except when it represents a substituted alkyl group, alkyl of 1-6 carbon atoms, or together represent an alkylene chain of 3-7 carbon atoms, and R11 represents the group -SO2R7 or

40. A compound according to claim 39 wherein R2 and R4 are the same or different and each represents an alkyl of 2-15 carbon atoms, alkylthio of 2-15 carbon atoms, alkenyl of 26 carbon atoms, alkynyl of 2-6 carbon atoms, cycloalkyl of 3-7 carbon atoms, phenyl, phenylthio, phenylalkyl of 7-10 carbon atoms, phenylalkylthio of 7-10 carbon atoms, furyl, pyranyl, pyrrolyl, pyridyl, quaternised pyridyl, or thienyl group, which group is unsubstituted or substituted by one or more substituents selected from halogen, hydroxy, mercapto, alkoxy of 1-6 carbon atoms, alkylthio of 1-6 carbon atoms, alkylsulphonyl of 1-6 carbon atoms, alkylsulphinyl of 1-6 carbon atoms, alkanoyl of 1-7 carbon atoms, nitro, cyano, carboxy, esterified, salified or amidated carboxy, amino, amino substituted by 1 or 2 alkyl groups of 1-15 carbon atoms, alkenyl or alkynyl of 2-6 carbon atoms, cycloalkyl of 3-7 carbon atoms, and, except when it represents substituted alkyl, alkyl of 1-6 carbon atoms.

41. A compound according to claim 40 wherein R5 represents a hydrogen atom and R6 represents an alkyl group of 1-15 carbon atoms.

42. A compound according to claim 38 wherein R represents an alkyl of 1-6 carbon atoms, alkenyl of 2-6 carbon atoms, alkynyl of 2-6 carbon atoms, cycloalky of 3-7 carbon atoms, cycloalkenyl of 3-7 carbon atoms, phenyl, phenylalkenyl of 7-10 carbon atoms, furyl, pyranyl, pyrrolyl, pyridyl, quaternised pyridyl, or thienyl group, which group is unsubstituted or substituted by one or more substituents selected from halogen, hydroxy, mercapto, alkoxy of 1-6 carbon atoms, alkylthio of 1-6 carbon atoms, alkylsulphonyl of 1-6 carbon atoms, alkylsulphinyl of 1-6 carbon atoms, alkanoyl of 1-7 carbon atoms, nitro, cyano, carboxy, esterified, salified or amidated carboxy, amino, amino substituted by 1 or 2 alkyl groups of 1-6 carbon atoms, and, except where R represents substituted alkyl, alkyl of 1-6 carbon atoms; R2 and R4 are the same or different and each represents a hydrogen atom or an alkyl of 1-15 carbon atoms, alkylthio of 1-15 carbon atoms, alkenyl of 2-6 carbon atoms, alkynyl of 2-6 carbon atoms, cycloalkyl of 3-7 carbon atoms, phenyl, phenylthio, phenylalkyl of 7-10 carbon atoms, phenylalkylthio of 7-10 carbon atoms, furyl, pyranyl, pyrrolyl, pyridyl, quaternised pyridyl, or thienyl group, which group is unsubstituted or substituted by one or more substituents selected from halogen, hydroxy, mercapto, alkoxy of 16 carbon atoms, alkylthio of 16 carbon atoms, alkynylsulphonyl of 16 carbon atoms, alkylsulphinyl of 1-6 carbon atoms, alkanoyl of 1-7 carbon atoms, nitro, cyano, carboxy, esterified, salified or amidated carboxy, amino, amino substituted by 1 or 2 alkyl groups of 1-15 carbon atoms, alkenyl or alkynyl of 26 carbon atoms, cycloalkyl of 3-7 carbon atoms, and, except when it represents substituted alkyl, alkyl of 1-6 carbon atoms; R6 represents a hydrogen atom or an alkyl of 1-15 carbon atoms, alkenyl of 2-6 carbon atoms, alkynyl of 2-6 carbon atoms, cycloalkyl of 3-7 carbon atoms, phenylalkyl of 7-10 carbon atoms or phenyl group, which group is unsubstituted or substituted by one or more substituents selected from halogen, alkoxy of 1-6 carbon atoms, nitro and, except when R6 represents a substituted alkyl group, alkyl of 1-6 carbon atoms; and R5 represents a hydrogen atom; -SO2R7 or

where A represents an oxygen or sulphur atom, Z represents a single bond, an oxygen or sulphur atom or an -NR8 group, R' represents alkyl of 1-6 carbon atoms, phenyl or phenylalkyl of 7-10 carbon atoms and R8 represents a hydrogen atom or a group as defined for R7; or an alkyl of 1-6 carbon atoms, alkenyl of 2-6 carbon atoms, alkynyl of 2-6 carbon atoms, cycloalkyl of 3-7 carbon atoms, phenylalkyl of 7-10 carbon atoms or phenyl group, which group is unsubstituted or substituted by one or more substituents selected from halogen, alkoxy of 1-6 carbon atoms, nitro and, except when R5 represents a substituted slkal group, alkyl of 1-6 carbon atoms; or R5 and R6 together represent a group of formula =CR9R10 where R9 and R10 are the same or different and each represent a hydrogen atom or an alkyl of 1-6 carbon atoms, phenyl or phenylalkyl of 7-10 carbon atoms group, which group is unsubstituted or substituted by one or more substituents selected from halogen, alkoxy of 1-6 carbon atoms, nitro and, except when it represents a substituted alkyl group, alkyl of 1-6 carbon atoms, or together represent an alkylene chain of 3-7 carbon atoms.

43. A compound according to claim 37 wherein R' represents a substituted or unsubstituted alkyl or aralkyl group; and R2 and R4 are the same or different and each represents a substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, cycloalkyl or cycloalkenyl group; with the proviso that R2 and R4 do not both represent methyl.

44. A compound according to claim 43 wherein R2 and R4 are the same or different and each represents a substituted or unsubstituted aryl group.

45. A compound according to claim 38 wherein R1 represents a substituted or unsubstituted alkyl, aryl or aralkyl group; and R2 and R4 are the same or different and each represents a hydrogen atom or a substituted or unsubstituted alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, aryl. aralkyl or alkylthio group.

46. A compound according to claim 45 wherein R2 and R4 are the same or different and each represents a hydrogen atom or a substituted or unsubstituted alkyl, aryl, aralkyl or alkylthio group.

47. A compound of formula

in which R' represents a substituted or unsubstituted alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, aralkyl or heterocyclic group; R3 represents a substituted or unsubstituted alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, aryl, aralkyl or heterocyclic group; R2 and R4 are the same or different and each represents a hydrogen atom or a substituted or unsubstituted alkylthio, arylthio or aralkylthio, group, or a group as defined for R3; and X- represents one equivalent of an anion; with the proviso that R2 does not represent hydrogen or a substituted or unsubstituted alkyl or aryl group when R' represents a substituted or unsubstituted alkyl group, R4 represents a substituted or unsubstituted alkyl or aryl group and R3 represents a substituted or unsubstituted alkyl group and with the proviso that any phenyl group of the group R4 is not substituted by -NO2.

48. A compound according to claim 47 in which R' represents an alkyl of 1--6 carbon atoms, alkenyl of 2-6 carbon atoms, alkynyl of 2-6 carbon atoms, cycloalkyl of 3-7 carbon atoms, cycloalkenyl of 3-7 carbon atoms, phenyl, phenylalkyl of 7-10 carbon atoms, furyl, pyranyl, pyrrolyl, pyridyl, quaternised pyridyl, or thienyl group, which group is unsubstituted or substituted by one or more substituents selected from halogen, hydroxy, mercapto, alkoxy of 1--6 carbon atoms, alkylthio of 16 carbon atoms, alkylsulphonyl of 1--6 carbon atoms, alkylsulphinyl of 16 carbon atoms, alkanoyl of 1--7 carbon atoms, nitro, cyano, carboxy, esterified, salified or amidated carboxy, amino, amino substituted by I or 2 alkyl groups of 16 carbon atoms, and, except where it represents substituted alkyl, alkyl of 16 carbon atoms; R3 represents an alkyl of 16 carbon atoms, alkenyl of 26 carbon atoms, alkynyl of 2-6 carbon atoms, cycloalkyl of 3-7 carbon atoms, cycloalkenyl of 3-7 carbon atoms, phenyl, phenylalkyl of 7-10 carbon atoms, furyl, pyranyl, pyrrolyl, pyridyl, quaternised pyridyl, or thienyl group, which group is unsubstituted or substituted by one or more substituents selected from halogen, hydroxy, mercapto, alkoxy of 1--6 carbon atoms, alkylthio of 16 carbon atoms, alkylsulphonyl of 16 carbon atoms, alkylsulphinyl of 1--6 carbon atoms, alkanoyl of 1--7 carbon atoms, nitro, cyano, carboxy, esterified, salified or amidated carboxy, amino, amino substituted by 1 or 2 alkyl groups of 1--6 carbon atoms, and, except where it represents substituted alkyl, alkyl of 16 carbon atoms; and R2 and R4 are the same or different and each represents a hydrogen atom or an alkyl of 1-15 carbon atoms, alkylthio of 1-15 carbon atoms, alkenyl of 2-6 carbon atoms, alkynyl of 2-6 carbon atoms, cycloalkyl of 3-7 carbon atoms, phenyl, phenylthio, phenylalkyl of 7-10 carbon atoms, phenylalklylthio of 7-10 carbon atoms, furyl, pyranyl, pyrrolyl, pyridyl, quaternised pyridyl, or thienyl group, which group is unsubstituted or substituted by one or more substituents selected from halogen, hydroxy, mercapto, alkoxy of 1--6 carbon atoms, alkylthio of 1-6 carbon atoms, alkylsulphonyl of 1-6 carbon atoms, alkylsulphinyl of 1-6 carbon atoms, alkanoyl of 1-7 carbon atoms, nitro, cyano, carboxy, esterified, salified or amidated carboxy, amino, amino substituted by 1 or 2 alkyl groups of 1-15 carbon atoms, alkenyl or alkynyl of 2-6 carbon atoms, cycloalkyl of 3-7 carbon atoms, and, except when it represents substituted alkyl, alkyl of 16 carbon atoms.

49. A compound according to claim 47 wherein R1 represents a substituted or unsubstituted alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, aralkyl or aromatic heterocyclic group; and R3 represents a substituted or unsubstituted alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, aryl, aralkyl or aromatic heterocyclic group.

50. A compound according to claim 37 or 47 wherein Xe represents chloride, bromide, iodide, acetate, hydroxide, sulphate, hydrogen sulphate, alkyl sulphate, p- toluene sulphonate, perchlorate or alkyl sulphonate.

51. A compound according to any one of claims 37, 38 and 47 wherein R1, R2, R3, R4, Re, Re, A, Z, ID=44.7

80. A process for preparing a compound claimed in claim 37 or 38 which has formula I wherein RC represents -SO2R7 or

which process comprises reacting the corresponding compound of formula I or II in which Re represents a hydrogen atom with a halide or anhydride of formula R6Y or ReORe, where Y represents a halogen atom.

81. A process for preparing a compound claimed in claim 37 or 38 wherein R5 represents

which process comprises reacting the corresponding compound in which Re represents a hydrogen atom with an isocyanate or isothiocyanate of formula RCNCO or RCNCS respectively.

82. A process for preparing a compound claimed in claim 47, which process comprises reacting a triazole of formula

with a compound of formula R3X.

83. A process for preparing a compound claimed in any one of claims 37, 38 and 47, which process is substantially as hereinbefore described.

84. A process for preparing a compound claimed in any one of claims 37, 38 and 47, which process is substantially as hereinbefore described in any one of the Examples.

85. A compound claimed in any one of claims 37, 38 and 47 when prepared by a process claimed in any one of claims 76-84.

86. A pesticidal or plant growth regulant composition comprising a compound as defined in claim 1 together with at least one material selected from solid carriers, a liquid carrier which is a hydrocarbon which boils within the range 130--270"C, surface active agents, other pesticides, other plant growth regulants, antidotes, ammonium sulphate, fertilizers and bases.

87. A pesticidal or plant growth regulant composition comprising a compound as claimed in any one of claims 37, 38 and 47 together with at least one material selected from carriers, surface active agents, other pesticides, other plant growth regulants, antidotes, ammonium sulphate, fertilizers and bases.

88. A composition according to claim 86 or 87 which contains a surface active agent.

89. A composition according to claim 86 or 87, which composition is substantially as hereinbefore described.

90. A composition according to claim 86 or 87, which composition is substantially as hereinbefore described in any one of the Examples 67 to 143, 158 to 162 and 166 to 192.

91. A process for preparing a composition claimed in any one of claims 86-90, which process comprises admixing the ingredients.

92. A composition claimed in any one of claims 86-90 when prepared by a process claimed in claim 91.

93. A method according to claim 1 wherein the compound is applied in the form of a composition claimed in any one of claims 86-90 and 92.