PT88080B - METHOD FOR THE PREPARATION OF 2- (REINFORCED IMINO) -1,3,4-DIHYDROTIADIAZOES AND THEIR INTERMEDIARIES - Google Patents

Description

2

with an appropriate compound.

Referring to Related Applications This application is a continuation in part of the application for Series NQ. 077 477, filed July 24, 1987. The present invention relates to a process for the preparation of novel herbicidal compounds of the dihydrothiadiazole type of formula

in which R is halogen, trihalomethyl, pentahalogenoethyl, mo -nofluoromethyl or difluoromethyl, monofluoroethyl, difluoroethyl, trifluoromethyl or tetrafluoroethyl, fluoralkylthio, fluoroalkoxy, methylthio, methylsulfonyl, halomethylsulfoonyl, alkyl or methoxy; n is 0, 1 or 2, with the proviso that:

(a) if n is 1 and R 2 is other than fluoro, the substituent R 1 is situated at the 3-position of the phenyl ring; and (b) if n is 2, the substituents R are situated at the 3- and 4-positions of the phenyl ring;

R 1 is hydrogen, C 1 -C 4 alkyl, C 1 -C 4 alkoxy, C 1 -C 4 alkylthio, C 1 -C 4 alkenylthio,

C1 -C4 alkylsulfinyl, cyano, carbamyl, C1 -C4 -alkylcarbamyl, C1 -C2 -alkoxycarbonyl, or NR2 R2 where R3 and R4 are independently hydrogen, C1-4 alkenyl and R2 is phenyl; monosubstituted phenyl or disubstituted phenyl wherein the substituents are selected from halogen, cyano and trihalomethyl; C1 -C4 monoalkyl-carbamyl or C1 -C4 dialkylcarbamyl; phenylcarbamyl; C 1 -C 4 -monoalkylthiocarbomyl; C -C-C--ketoalkenyl; cyano; C 1 -C 4 -alkylsulfonyl; C 1 -C 4 haloalkylsulfonyl; or C- (Y) m -R5 wherein Y is oxygen or sulfur; m is 0 or 1; and is C1 -C4 alkyl which is C2 -C8 alkynyl wherein m is 0; C 1 -C 6 alkenyl wherein the triple bond is separated from the oxygen or sulfur atom (Y) by at least one methyl group if m is 1; C1-6-haloalkyl if m is 0; C2-C6-haloalkyl if m is C2 -C10 -alkoxyalkyl if m is 0; pyridyl if m is 0; C 1 -C 4 -alkoxyalkyl wherein the alkylene moiety has at least two carbon atoms if m is 1; or R6 is (R6> pR7 wherein p is 0 or 1, R8 is a C1 -C2 alkylene group and R1 is 4

phenyl,

Cy C3 -cycloalkyl, phenyl substituted by halogen; optionally substituted by 1 to 3 methyl groups; C? -C? -C? -Alkoxy; or saturated or unsaturated heterocyclic ring containing from 5 to 6 atoms including from 1 to 2 selected oxygen and sulfur heteroatoms, optionally substituted by 1 to 3 methyl groups and optionally substituted by 1 to 2 oxo groups; with the proviso that when R1 is methylthio and R2 is isopropylcarboxy, R3 is not 2-fluoro.

In the above definition the term " halogen " includes fluorine, chlorine, bromine and iodine.

When the phenyl ring shown in the basic structure is disubstituted (n = 2) the two substituents may be the same or different and are chosen from those mentioned in the definition of part R. When the phenyl ring is monosubstituted, the substituent R is preferably in the meta position. The term " alkyl " refers to straight and branched chain acyclic hydrocarbyl groups having the number of carbon atoms associated with that term always used (ie, by itself or as part of the definition of another part, eg " halogen-alkyl " alkylthio ", etc.). Examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl and the various penyl, hexyl, and the like. The term " is-C? -H-q " (isoamyl or isopentyl) refers to the 3-methylbutyl group. The term " sec-CyH- " designates the 2-pentyl group. The term " carboalkoxy " refers to parts of the specified number of carbon atoms having the structure -C-O-A, wherein A represents an alkyl, alkylalkoxy and alkylcarboalkoxyl group having the required number of carbon atoms. Such examples of carboalkoxy moieties include carbomethoxy, carboethoxy, 1-methylcarbomethoxymethyl and the like. 5

The terms " alkylcarbamyl " and " alkylthiocarbamyl " refer to parts having the structures

s

IL

-CN

-CN wherein the nitrogen atom is further substituted by one or two alkyl groups as defined, the alkyl groups containing the indicated number of carbon atoms. In the dialkylcarbamyl compounds of the present invention the two alkyl groups may be the same or different. The term " carbamyl " when used by itself refers to the unsubstituted or -COH 2 part.

Examples of such substituted groups include methylcarbamyl, ethylcarbamoyl, dimethylcarbamyl, N-methyl-N-ethylcarbamyl and the like. The term " alkenyl " refers to straight and branched chain monosaturated or polysaturated hydrocarbyl groups having the number of carbon atoms as specified. Examples of alkenyl groups include vinyl, allyl, propenyl, isopropenyl, isobutenyl, and the like. The term " ketoalkenyl " refers to an alkenyl group in which a carbon atom is doubly attached to an oxygen atom. An example is 3-keto-1-butenyl. The term " alkynyl " refers to straight and branched chain acyclic hydrocarbyl groups having at least one triple bond. An example is propargyl (2-propynyl). The term " cycloalkyl " refers to saturated cyclic hydrocarbyl groups having the specified number of carbon atoms and includes cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and cycloheptyl. The term " halogenoalkyl " refers to alkyl groups or alkoxy groups having the indicated number of carbon atoms substituted by one or more halogen atoms which may be the same or different. When unspecified, the terms " ha-logen-alkyl " and " alkoxy " are understood to refer to alkyl groups or alkoxy groups ranging from monohaloalkyl or monofluoroxy to fully substituted haloalkyl groups. Examples of the halogenoalkyl and fluoroalkoxy group include chloromethyl, dichloromethyl, difluoromethoxy, trifluoromethyl, trifluoromethoxy, 2-chloroethyl, pentafluoroethyl, pentafluoroxy, heptafluoropropyl, heptafluoropropoxy, 3-chloropropyl, 2,2,2-trifluoro-1 2,2,2-trifluoro-1-methylethoxy, J, 1,2,2-tetrafluoroethoxy and the like. The term " halogenoalkylsulfonyl " indicates a sulfonyl group attached to a haloalkyl group, for example, chloromethylsulfonyl. The term " alkoxyalkyl " denotes an alkyl group substituted by an alkoxy group, for example methoxymethyl, methoxyethyl, ethoxyethyl, and the like. The indicated number of carbon atoms refers to the total number of carbon atoms in the alkoxyalkyl group (e.g. C2 for methoxymethyl, ethoxymethyl and the like). When it is alkoxyalkyl and m is 0, the oxygen atom on the alkoxyalkyl group may be positioned anywhere on the chain. When m is 1, however, there must be at least two carbon atoms in the " alkylene " of the alkoxyalkyl group; that is, there must be at least two carbon atoms separating the oxygen atom or the sulfur atom represented by the symbol " Y " and the oxygen atom of the alkoxyalkyl group (i.e., the alkoxyalkyl group is at least one alkoxyethyl group). The value of p may be 0 or 1. When p is 0, there is a 7

Π direct link between the Ry group and the -C (Y) m group. When p is 1, R 1 and the group -C (Y) m R 2 are attached by a C 1 -C 6 alkylene group, for example a methylene or 1,1-ethylene or 1,2-ethylene group.

The heterocyclic rings included in the definition of Ry may be saturated or may be mono-unsaturated, di-unsaturated or tri-unsaturated. Such rings may contain one or two oxygen or sulfur atoms, for example, furanyl, tetrahydrofuranyl, tetrahydropyranyl, 1,3-dioxolanyl, 1,3-dioxanyl, 1,4-dioxanyl, tetrahydrothienyl, pyridyl and the like, optionally substituted by 1 to 3 methyl groups. In addition to or alternatively to methyl substitution, the heterocyclic ring may have one or more oxygen atoms doubly attached to the ring carbon or sulfur atoms.

I

Preferred substituents are: for Rn-meta-halogen, -trihalogenomethyl, fluoralkoxy or fluoralkylthio, in particular meta-chloro, metafluor, meta-trifluoromethyl, difluoromethoxy, tetrafluoroxy, and trifluoromethylthio, 3-chloro, 4-fluoro and 3-trifluoromethyl, 4-fluoro; for Râ,, - alkyl (especially methyl or ethyl), alkoxy (in particular methoxy), methylthio and dimethylamino; and for R 4 -fluorophenyl, monoalkylcarbamyl (especially methylcarbamyl, ethylcarbamyl, n-propylcarbamyl and isopropylcarbamyl), alkylcarbonyl (R 4 is alkyl, m is 0, including both straight and branched chain alkyl groups, especially C1-6 alkoxycarbonyl, n-propylcarbonyl, isopropylcarbonyl, isobutylcarbonyl and 2-methylbutylcarbonyl), carboalkoxy (R3 is alkyl, m is 1, Y is oxygen, both straight chain alkyl and C,-C, alkyl, such as carbomethoxy, carboethoxy, carbo-n-propoxy, carboisopropoxy, carboisobutoxy, and the like), C₂-C--haloalkylcarbonyl (R é is haloalkyl, in particular polyfluoro - 8

(C 1 -C 6 -alkyl and C 1 -C 4 -alkyl and C 1 -C 4 -alkyl), C 1 -C 4 -alkyl and C 1 -C 4 -alkyl , m is 1 and Y is oxygen), optionally methyl substituted cycloalkylcarbonyl (R4 is p is 0, m is 0, Ry is cycloalkyl, in particular cyclopropyl, cyclopentyl, methylcyclopentyl, or cyclohexyl), carbocycloalkoxy optionally substituted by methyl (R4 is (Rg) pRy> p is 0, m is 1, Y is oxygen, R7 is cycloalkyl, in particular cyclopropyl, cyclopentyl, methylcyclopentyl or cyclohexyl), cycloalkylmethylcarbonyl optionally substituted by methyl (R3 is (Rg) pRy, wherein m is 0, Rg is methylene, Ry is as above for cycloalkyl), carbo-cycloalkylmethoxy optionally substituted with methyl (R4 is (Rg) pRγ> p is 1, m is 1, Y is oxygen, Rg is methylene, Ry is as above for cycloalkyl), heterocyclic carbonyl (R4 is (Rg) p R4, p is 0, m is 0, and Ry is a 5- or 6-membered heterocyclic ring containing 1 or 2 oxygen and / or sulfur atoms, optionally substituted by 1 to 3 methyl groups and optionally substituted by 1 or 2 oxo groups, in particular furanyl, tetrahydrofuranyl, tetrahydropyranyl, dioxolanyl, dioxanyl, tetrahydrothienyl, tetrahydro-1 (Râ, â, ‡ Râ, †), P is 0, m is 1, Y is oxygen and Ry is a heterocyclic ring such as as defined above), heterocyclyl-methyl carbonyl (p is 1, m is 0, R6 is methylene, R7 is heterocyclic) and carbo- (methoxy heterocyclic) (p is 1, m is 1, Y is oxygen, methylene and Ry is heterocyclic).

When it is indicated that a phenyl ring may be di- or more substituted, the substituents may be the same or different and are selected from the groups specified. When no specific position of the substitution on a phenyl ring is mentioned, it is meant that the substituent or substituents may be substituted at any position of the ring. 9

(Μ-

The compounds of the present invention have been found to be active herbicides having pre-emergence and / or post-emergence vipicidal activity against various types of weeds, including broadleaf and grass weeds. As mentioned below, some of the compounds demonstrate selective control of weeds in certain crops, such as cereals, including wheat, rice, barley and cotton. The present invention therefore also relates to a method for controlling undesirable vegetation comprising applying to a location where control of such vegetation is desired, or prior to or subsequent to the emergence of such vegetation, a herbicidally effective amount of a compound as described in the invention, and also relates to herbicidal compositions which comprise a herbicidally effective amount of a compound as described herein, together with an inert diluent or carrier suitable for use with herbicides.

As used herein, the term " herbicide " refers to compounds that adversely control or modify the growth of plants, in particular undesirable plants. By the term " herbicidally effective amount " is meant a number of compounds that cause an adverse control or modification effect on plant growth. The term " plants " includes germinating seeds, cuttings, and established vegetation, including roots and parts above ground. These adverse effects of modification and control may include all deviations from natural development.

There are several processes by which the compounds of the present invention can be prepared. Some of these processes, as well as intermediates, are also novel and form other aspects of the present invention. 10

Process A:

Reaction of a substituted thione-hydrazine with an imidoyl dihalide

In this process the appropriate thionohydrazine is reacted with an imidoyl dihalide in the presence of a base, according to the reaction:

Hal

Hal c = n-r 2 - > Base

II

wherein R 1, R 2, R 2 and n are as previously described and Hal represents a halogen, preferably chlorine. Both halogens (Hal) are identical. This reaction is conducted at a temperature of from about -100Â ° C to about + 150Â ° C, preferably from about -78Â ° C to about + 80Â ° C. Suitable bases include trialkylamines, preferably lower trialkylamines, such as triethylamine, pyridine, alkali metal hydrides (preferably sodium hydride) and tertiary alkali metal alkoxides, such as sodium and potassium tertiary butoxides. Suitable solvents include dimethylformamide, tetrahydrofuran, 1,2-dichloroethane and benzene.

This method is the preferred process for the production of arylimino compounds (R2 is phenyl or substituted phenyl), but may be used for the preparation of all compounds of the present invention.

The starting materials for this process are readily available. The imidoyl dihalides may be prepared according to the literature, for example, by reaction of formanilides with thionyl chloride and sulfuryl chloride.

The thionohydrazines are prepared as described below.

All intermediates and end products in the following examples, as well as those which appear subsequently, have been identified by typical spectroscopic methods, including nuclear magnetic resonance, infrared and mass spectroscopy.

Examples of the preparation of compounds are given below by process A.

Example 1 Preparation of 2- (4-fluorophenyl) imino-3- (3-trifluoromethyl) phenyl-5-methoxy-2,3-dihydro-1,3,4-thiadiazole (Compound 99 below) a) Preparation of thionohydrazine

In a 100 milliliter (ml) vessel were placed 6.5 grams (g) (0.03 moles) of 25% sodium methoxide and 2.3 g (0.03 moles) of carbon disulfide. This mixture was stirred for 20 minutes and 10 ml of water and 3.5 g (0.03 mole) were added.

) of chloroacetic acid sodium salt and stirred for one hour. Most of the solvent was then removed under vacuum and replaced with 10 ml of methanol and 4.4 g (0.025 mol) of (3-trifluoromethyl) phenylhydrazine. This mixture was then heated in a running bath for 0.5 hour and the solvent evaporated off. The residue was dissolved in ether, washed with water, the phases separated, dried and stripped to give 5 g of solids. b) In a 100 ml vessel was added 2.5 g (0.01 mole) of the intermediate product obtained in step (a), 15 ml of 1,2-dichloroethane and 1.9 g (0.01 mole) of 4-fluorophenyl imidoyl dichloride. This stirred solution was cooled in an ice bath and 2.8 ml (0.02 mol) of triethylamine were added. The mixture was stirred cold for 0.5 hour and then refluxed for 0.5 hour. The solution was washed with water, the phases separated, dried and stripped. The residue was treated with 50 ml of hot hexane, decanted and allowed to cool. Solids were collected to give 2.2 g (mp 113 DEG-5øC) identified as the expected product. . PROCESS B:

The compounds of the present invention wherein R2 is C1 -C4 -alkylcarbamyl, phenylcarbamyl, alkylthiocarbamyl, cyano, ketoalkenyl, alkylsulfonyl, haloalkylsulfonyl or wherein Y, m is R 2 are as defined above, may be prepared by a two step procedure representing the following scheme:

NH (NH2) II

2-imino-3- (subs-phenyl-thio-1H-

In the first step of this process, a thiophenyl) thiadiazole is prepared by cyclizing a drazine of formula

with a cyanogen halide having the formula Z-CN wherein Z is chloro or bromo. The cyclization reaction is conducted in the presence of an inert solvent, such as diethyl ether, a chlorinated hydrocarbon solvent (e.g., methylene chloride, chloroform or 1,2-dichloroethane) or a

such as toluene. The temperatures may range from about -50 ° C to about + 150 ° C, preferably being from about -5 ° C to about 255 ° C. The process, when carried out in this manner, produces the hydrohalogen product of the intermediate iminothiadiazole, which is indicated by the use of the term " (.HZ) " in the above equation. In an alternative embodiment this cyclization reaction may be conducted in the presence of an appropriate base such as sodium hydride or a tertiary amine to produce the free iminothiadiazole intermediate, or the free intermediate may be produced by the neutralization of the hydrohalide salt when complete the reaction. The iminothiadiazole intermediates and their hydrohalide salts are novel and may also contain herbicidal activity. The iminothiadiazoles correspond to the general formula

wherein R 1 and n are as defined above and R 2 is hydrogen.

In the second step of this process the intermediate iminothiadiazole compound (as free compound of the hydrohalide salt) is reacted with the appropriate acylating agent in the presence of an appropriate base. 0

If the desired product is one in which R 2 has the formula: The acylating agent has the formula Z 'C (Y) m -R 5, wherein Z' is a halogen, preferably chlorine, bromine or iodine. If the desired product is one in which is C1 -C4 -alkylcarbamyl, C1 -C4 -alkylthiocarbamyl or phenylcarbamyl, the acylating agent is the appropriate isocyanate or the appropriate isocyanurate (R6 NCO or RgNCS wherein R6 is C1-4 alkyl Or phenyl). If the iminothiadiazole intermediate is used in the form of its hydrohalide salt, one molar equivalent of the base is required. Suitable bases include amines, sodium hydroxide and sodium bicarbonate. This acylation reaction may be carried out in the presence of a solvent typically used for acylation reactions, for example toluene, methene chloride or diethyl ether. The temperature of the acylation reaction may range from about -50 ° C to about + 150 ° C, preferably from about 0 ° C to about 25 ° C.

The substituted phenyl-thionohydrazines

S NHNHCRi where η = 1 or 2 are also new. They can be prepared in a number of ways, depending on the definition of R '^.

The thionohydrazines in which R1 is alkylthio or alkenylthio may be prepared by reacting a substituted phenylhydrazine with carbon disulfide in the presence of a base and an alkylating agent such as an alkyl or alkenyl halide ( iodide, chloride or bromide), sulfate etc. This reaction is conducted at a temperature generally in the range of about -50 ° C to about + 150 ° C, preferably at about 0 ° C to about 25 ° C. A solvent may be used which is inert towards the reactants or products, for example, diethyl ether, tetrahydrofuran, toluene or benzene. The base is 16

preferably a weak base, such as a trialkylamine, pyridine or potassium carbonate.

The thionohydrazines in which it is alkoxy can be prepared by reacting the appropriate substituted phenylhydrazine with di-thiocarbonate

s

Wherein R 4 is C 1-6 alkoxy and R 9 is a C 1-4 alkyl group or a methylcarboxy group. This reaction is again carried out at temperatures of from about -50 ° C to about + 150 ° C, preferably from about 80 ° C to about 110 ° C. The reaction may be carried out with or without solvent. If carried out with a solvent, inert solvents such as toluene, tetrahydrofuran, alcohol or alcohol-water mixtures may be employed. The dithiocarbonate can be produced by reacting an alkali metal alkoxide with carbon disulfide in the presence of an alkylating agent which introduces the Rg group. This reaction may be carried out in pure alcohol, ethereal solvents such as tetrahydrofuran or dimethyl ether, or other inert solvents, for example dimethylformamide. The temperature may be between about -50 ° C and about + 150 ° C, preferably between about 60 ° C and about 80 ° C. The R 8 group is preferably a group which is easily substituted as R 6 -S- at a later stage of the general process. Accordingly, R g is preferably a small group or groups such that the general RgSH group is a good leaving group and is either volatile or water soluble. Thionohydrazine wherein R3 is a C1 -C4 alkyl group is preferably effected by reacting the appropriate substituted phenylhydrazine with phosphorus pentasulfide. The reaction temperature is between about -50 ° C and about + 150 ° C, preferably between about 80 ° C and about 110 ° C. This reaction

may be carried out in the presence of an inert solvent, for example benzene, toluene, xylene or dioxane.

The thionohydrazines in which is NR? R? Can be prepared from thionohydrazines in which R? Is thioalkyl by reacting with an appropriate amine. This process is carried out in the presence of a solvent, preferably an alcoholic solvent, optionally other solvent such as dimethylformamide, toluene or 1,2-dichloroethane. The temperature of this reaction is between about -50 ° C and about + 150 ° C, preferably between about 80 ° C and about 110 ° C.

The following examples are representative of the type B process. EXAMPLE 2

Preparation of 2- (acetyl) imino-3- (3-trifluoromethyl) phenyl-5-methylthio-2,3-dihydro-1,3,4-thiadiazole (Compound 44 together) a) Preparation of thionohydrazine

200 ml of toluene, 14 ml of triethylamine (0.1 mole) and 17.6 g of (3-trifluoromethyl) phenylhydrazine (0.1 mole) were charged into a one liter vessel. This solution was cooled in an ice bath and 10 ml of carbon disulfide (0.167 moles) was added dropwise, but dropwise. This solution was stirred for one hour and then 10 mL of dimethyl sulfate (0.106 moles) (there was a slight release of heat) was added dropwise, but dropwise. The mixture was stirred overnight at room temperature. To this was added 250 ml of water and 200 ml of diethyl ether. However,

the reaction was dried, dried over magnesium sulfate and the ether removed under reduced pressure to give solids which were washed with pentane to give 17.2 g of solids (mp 14 DEG-149 DEG C.). b) Cyclization to the iminothiadiazole intermediate

In a 250 ml vessel was charged 8.0 g (0.03 mol) of the product of step (a) and 50 ml of toluene. This mixture was cooled in an ice bath and 4.1 g of cyanogen bromide (0.04 mol) in 50 ml of toluene was added. The mixture was stirred for several hours at room temperature. The solids were collected by filtration to give 7.1 g. c) Acylation

In a 100 ml flask was placed 3.7 g of the solid just obtained (0.01 mole), 20 ml of methylene chloride and 0.8 ml of acetyl chloride (0.011 mol). This solution was then cooled in an ice bath and 2.2 ml of pyridine (0.022 mol) was added dropwise. The solution was stirred for one hour and worked up in usual manner to give 3.2 g of solids, m.p. 95-97 ° C. EXAMPLE 3

Preparation of 2- (carboethoxy) imino-3- (3-trifluoromethyl) phenyl-5-dimethylamino-2,3-dihydro-1,3,4-thiadiazole Compound 82 together) a) Preparation of thionohydrazine

50.5 g (0.19 mol) of 1-methyl-dithiocarbonyl-2- (3-trifluoromethyl) phenylhydrazine (pre-

quenched according to Example 2a), 350 ml of ethanol and 83 ml (0.6 mol) of aqueous dimethylamine at 40 ° C. The solution was refluxed for 5 hours and the solvent was evaporated by entrainment. The solids were washed with ether to collect 33.9 g of solids; mp 162-168 ° C. b) Cyclization

In a 500 ml vessel was placed 11.9 g (0.045 mol) of the above product and 120 ml of toluene. This solution was then cooled in an ice bath and 5.3 g (0.05 mol) of cyanogen bromide in 40 ml of toluene was added dropwise. The slurry was stirred overnight and filtered to recover 15.7 g of the solid hydrobromide salt. c) Acylation

In a 100 ml flask was placed 3.4 g (0.009 mol) of the solids obtained in step (b), 20 ml of methylene chloride and 1.0 ml of ethyl chloroformate (0.01 mol). This mixture was cooled in an ice bath and 1.6 ml (0.02 mol) of pyridine dissolved in 5 ml of dichloromethane was added dropwise. The mixture was stirred for 1 hour and washed with water, separated, dried, and evaporated by argon to give 3.2 g of solids (mp 92-93 ° C), identified as the product required. EXAMPLE 4

Preparation of 2- (carboisopropoxy) imino-3- (3-trifluoromethyl) phenyl-5-ethoxy-2,3-dihydro-1,3,4-thiadiazole (Compound 83 below) a)

Preparation of dithiocarbonate 20

In a 500 ml flask was placed 100 ml of ethanol and 24 g (0.3 mol) of 50% sodium hydroxide. To this stirred solution was added 21 ml (0.35 mol) of sodium disulfide, dropwise. This solution was stirred for 0.5 hour and 33 ml (0.35 mol) of dimethyl sulfate were added dropwise. The mixture was stirred overnight at ambient temperature. The ethanol was evaporated by stripping and the residue was taken up in ether, washed with water, dried and stripped to give 34 g. h) Preparation of thionohydrazine

8 g (0.06 mol) of the product of step (a) and 8.8 g (0.05 mol) of (3-trifluoromethyl) phenyl-hydrazine were charged to a 200 ml beaker. The solution was heated in the standard bath for 5 hours and then spray-evaporated to remove the lower boiling components, giving 15.2 g of a thick oil. c) Cyclization

The product of step (a) was dissolved in 150 ml of toluene and 6.1 g (0.06 mol) of cyanogen bromide was added in one portion. This mixture was stirred overnight and filtered to recover 7 g of solid hydrobromide. d) Acylation

3.5 g (0.01 mole) of the product of step (c), 20 ml of methylene chloride and 1.2 ml (0.011 mol) of isopropyl chloroformate were charged into a 100 ml vessel. This mixture was stirred and cooled in an ice bath, and 1.7 ml (0.21 mol) of pyridine in 5 ml of methylene chloride was added dropwise. The mixture was stirred for one hour and worked up in usual manner to give 3.3 g of solid, m.p. 105-161 ° C, identified as the expected product.

5

EXAMPLE

Preparation of 2- (carbo-n-propoxy) imino-3- (3-trifluoromethyl) phenyl-5-ethyl-2,3-dihydro-1,4,4-thiadiazole (Compound 117 below) a) Preparation of thiono -hydrazine

50 g (0.28 mol) of (3-trifluoromethyl) phenylhydrazine, 250 ml of methylene chloride, 250 ml of 20% sodium hydroxide and 250 g of ice were charged into a 2 liter vessel. The stirred mixture was cooled in an ice bath and 25 ml (0.28 mol) of propionyl chloride were added dropwise. After addition, this mixture was stirred for one hour, the phases were separated, dried over magnesium sulfate and the organic products were evaporated by stripping to recover 54 g of solids. 25 g (0.11 mol) of the newly obtained solids and 350 ml of benzene were charged to one liter vessel. With stirring, 50 g of N, N-dimethylformamide were added and the slurry was refluxed for 0.25 hour. Twenty ml of water were then carefully added, followed by another 350 ml of water. The mixture was refluxed until all solids had dissolved, then cooled and the layers were separated. The organic layer was dried and the solvent was evaporated by stripping to give 29 g of the expected intermediate. b) Cyclization

This material (0.12 mol) was then dissolved in 125 ml of toluene and cooled in an ice bath. With stirring, 8 g (0.13 mol) of cyanogen chloride were added in 30 ml of toluene. The mixture was stirred overnight at ambient temperature, then filtered to give 11 g of solid hydrochloride. 22

£ 2

Acylation

3.7 g (0.012 mol) of the product of step (b), 15 ml of methylene chloride and 1.5 ml (0.013 mol) of n-propyl chloroformate were charged into a 100 ml vessel. The stirred mixture was cooled in an ice bath and 2.1 mL (0.026 moles) of pyridine was added dropwise. The mixture was stirred for one hour, washed with water, and the phases were separated. The organics were dried and stripped to give 3.0 g of solids (mp 53-56øC), identified as the expected product.

OTHER PROCESSES

Herbicidal compounds wherein R4 is alkylsulfinyl or alkylsulfonyl are prepared by the oxidation of corresponding compounds wherein R3 is alkylthio, under conventional conditions for such oxidations.

Herbicidal compounds wherein R4 is cyano, carbamyl or monoalkylcarbamyl are prepared through the corresponding dihydrothiadiazoles in which R1 is C1-4-carboalkoxy. These are prepared using Method B. The thionohydrazines in which C--C₂ carbo-carboalkoxy are prepared by reacting the appropriate phenylhydrazine with methyl or ethyl chloride or oxalyl or dimethyl or diethyl oxalate by reaction in followed by the product with phosphorus pentasulfide such as in the preparation of thionohydrazines in which R3 is an alkyl group.

Herbicidal compounds wherein R4 is carbamyl or monoalkyl-C1 -C4 -carbamyl are prepared by reacting those compounds wherein R3 is carboalkoxy with ammonia or a monoalkylamine, respectively. Compounds in which R1 is cyano are prepared by the dehydration of the corresponding compounds of 23

conventional carbamyl conditions.

Compounds wherein R1 is C1 -C2 carboalkoxy are useful as intermediates for the preparation of the corresponding cyano, carbamyl or monoalkylcarbamyl intermediates. The following Table I shows representative compounds of the present invention. TABLE I Thiadiazis

Comp.

mp. R 1 R 2 or n D 30 1 3-CF 3 NHCH 3 3-CF 3 -C 6 H 5 oil 2 3-C 3 NHCH 3 4-F-C 6 H 5 semi-solid 3 3-CF 3 k CH 3 4-Cl-C 6 H 5 -Br-C6H5 semi-solid 5 3-CF3 NHCH3 3,4-Cl-C6H5 semi-solid 6 3-CF3 n (ch3) 2 4-F-C6H5 105-110 24

Comp. NS. 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 R TABLE I (continued) p. f. (CH 3) 2 3-CF 3 -C 6 H 5 85-94 3 -C 3 N (CH 3) 2 4-Br-C 6 H 5 140-146 3-CF3 n (ch3) 2 3,4-Cl-C6H5 103-110 3-CF3 n (ch3) 2 4-Cl-C6H5 129-137 3-ct3 n (ch3) 2 4-CN-C6H5 166-168 3-CF3 SCH3 3-cf3-c6h5 95-98 3-CF3 SCH3 4-Br-C6H5 125-129 3-CF3 SCH3 3,4-Cl-C6H5 66-75 3-CF3 SCH3 4-Cl-C6H5 114-124 3-CF3 sch3 4-CN-C6H5 128-135 3-CF3 SCH3 C (O) HH-C3H7 126-127 3-CF3 SCH3 co-C3H7 87-90 3-CF3 SGH3 C ) -i-C4Hg 75-78 3-CF3 n (ch3) 2 coo-C3H7 130-133 3-CF3 SCH3 cooc2-5 59-62 3-CF3 SCH3 C (O) -S- (C3H7) 57-62 3 -CF 3 SCH 3 -O (O) CH 2 = 60-64 3-CF 3 SCH 3 COO -CH 3 CH 3 SCH 3 C (O) NH-CH 3 -87 25

TABLE I (continued)

Comp. mp. R 1 R 2 or nD 28 28 3-CF 3 SCH 3 C (O) SC 2 H 5 73-79 29 3-cf 3 SCH 3 C (O) NH-n-C 3 H 7 111-113 30 3-C 12 H 5 COO- 31 3-CF3 OCH3 COO-i-C3H7 98-100 32 3-CF3 OCH3 C (O) NH3 -C3 H7 163-165 33 3-CF3 OCH3 C (O) -i-C4 Hg 35-38 34 3-CE3 n (ch3) 2 C (O) -i-C4 Hg 1.5637 35 3-CF3 sc2h5 C (O) -Si-C3H7 6leo 36 3-c3 3 sc2h5 C (O) NH- (C3H7) 135-138 37 3-CF3 sc2h5 COO-C3H7 78-81 38 3-CE3 sc2h5 C (O) -i-C4Hg semi-solid 39 3-C3 3 sc2h5 C (O) -n-C3H7 54-58 40 3-C (CH3) 2 CH3 (CH3) 2 CH2 (CH3) 2 CH2 (CH3) 2 CH2 (CH3) 2 CH2 (CH3) 2 CH2 (CH3) 86-90 43 3-OF3 OCH3 c (o) ch = c (ch3) 2 107-111 44 3-CF3 SCH3 c (o) ch3 95-97 45 3-CF3 SCH3 C (O) CH = C (CxH3) 2 99-100 46 3-CF3 SCH3 c (0) ch2-Q-F 94-96 26

Comp. NS. (CH3) = CH2 90-96 3-CF3 SCH 3 C (O) NHC 2 H 5 78-84 49 3-CF 3 n (CH 3) 2 C (O) 0) -S-γ-C3H7 98-102 50 3-CF3 n (ch3) 2 C (O) CH = C (CH3) 2 118-121 51 3-CF3 SCH3 c (o) 52 3-CF 3 SCH 3 C (O) CH 3 CH 3 C (O) -n-C 3 H 7 45 3-CF 3 SCH 3 C -48 55 3-OF3 SCH3 C (O) CH2 CH (CH3) CF3 1.5855 56 3-C1 -CH3 C (O) O-C3 H7 wax 57 3-Cl SCH3 C (O) -i-C4 Hg 1.6290 58 3-Cl SCH 3 C (O) NH-i-C 3 H 7 wax 59 3,4-Cl SCH 3 COO-C 3 H 7 98-101 60 3.4-01 SCH 3 COO- C (O) NH-i-C 3 H 7 125-128 62 3-F SCH 3 COO-i-C 3 H 7 wax 63 3-F SCH 3 C (O) C3H7 wax 65 2-Fc3 C (O) -i-C4Hg wax 66 2-Fc3 C3H7 140-144 67 4-Fc3 COO-C3H7 wax Comp . N2. R 1 -R 2 p -F or C D -H 3 -CF 3 SCH 3 -C (O) -cycloalkyl 1,6000 69 4-F SCH 3 C (O) NH 3-C 3 H 7 124-126 70 3-CF 3 OCH 3 C00CH3 126-129 71 3-CF3 och3 COOC2H5 84-87 72 3-CF3 OCH3 COO-n-C3H7 49-52 73 3-CF3 OCH3 COO-C3 Hg 43-47 74 3-CF3 OCH3 COO-n-C3 H5 1.5454 75 3-CF3 och3 COO-nC3 Hg 43-47 76 3-cp3 OCH3 cooch2ch = ch3 60-76 77 3-OP3 OCH3 C00-sec.-CgH41 41-46 78 3-CP3 OCH3 COO-sec. 85-87 79 3-CF3 OCH3 cooch2ch2ci 66-69 30 3-CF3 OCH3 cooch2ch2och3 55-59 81 3-CF3 n (ch3) 2 COO-sec-C3 Hg 129-131 82 3-CF3 n (ch3) 2 COOC 2 H 5 92-93 83 3-CF 3 OC 2 H 5 COO-C 3 H 7 3-CF 3 OC 2 H 5 C (O) -i-C 4 Hg semi-solid 85 3-SCF 3 OCH 3 COO-C 3 H 7 1.5485 86 3-SOF 3 3-CF3 N (CH3) n-C3 H7 -CO-C3 H7 75-85 88 3-CF3 N (CH3) n -C3 H7- C (O) -i-C4 H5 1.5375 28 /; < ,

ΤΑΒΞΙΑ I (continued)

Comp. R 1 r 2 pf ° C or n D 30 89 3-SCF 3 SCH 3 COO-C 3 H 7 80-84 90 3-SCF 3 SCH 3 C (O) -i-C 4 Hg 45-48 91 3-Cl 0 CH 3 COO- 3-Cl 0 CH 3 c (o) -i-C 4 H 9 1.5790 93 3-Cl 0 CH 3 C (O) NH-1 - 3H 3H 119-121 94 C- 95 3-Cl 0 CH 3 COOC 2 H 5 121-123 96 3-Cl 0 CH 3 COO-sec C 4 H 9 50-59 97 3-CF 3 0 CH 3 COOCH (C 2 H 5) 2 66-73 98 3-CF 3 OCH 3 co- 4-F-C6H5 113-115 100 3-CF3 n (ch3) 2 C (O) CH3 CH3 CH3 CH3 CH3 CH3 CH3 CH3 CH3 CH3 CH3 CH3 CH3 CH3 0CH3 C (O) CH3 76-80 103 3-CF3 0GH3 c (o) c2h5 semisolid 104 3-CF3 C (O) -n-C3H7 1.5402 105 3-CF3 OCH3 0 (0) -1- 0, 1 H -1 1.5243 106 3-CF 3 0 CH 3 C (O) CH 3 CH 3 CH 3 CH 3 CH 3 CH 3 CH 3 CH 3 CH 3 CH 3 CH 3 CH 3 CH 3 CH 3 CH 3 CH 3 CH 3 CH 3 CH 3 CH 3 OCH 3 COOC6 H5 128-133 110 3-CF3 OCH3 COO-n-C6 H13 1.5181 29 29

TABLE I (continued)

Comp.N2. 111 112 113 114 115 116 117 118 119 R, 120 R R1 3-CE3 0CH3 3-CF3 0CH3 3-CP3 0CH3 3-CP3 0CH3 3-CF3 C2H5 3-CP3 C2H5 3-CP3 c2h5 3-CP3 C2H5 3-CF3 0CH3 3-CF 3 OCH 3 G (O) -sec.-C 5 H 11 cooch 2 c 6 h 5 c (o) cf2cf2cf3 pf C or nB3Q 1.5307 93-100 65-67 S02-n-C3Hy semi-s COO- / 94-96 0 (0) -O-C3 H7 53-56 COO-C, Hn 49 9 1.52 50 1.5340

1.5348 121 122 3-CP3 0CH3 3-CP3 n (ch 82.88 C00-

122-124 30

TABLE I (continued)

Comp. 123 124 125 126 127 128 129 130 131 132 133 134 135 136 pf ° C o R R1 r2 nD30 3-CF3 SCH3 c (o) nhc6h5 161-163 3-cp3 NHCH3 COO-CH3 141-156 3-CF3 CH3 COO-C3H7 113-118 3-Οϊ3 oh3 0 (0) -1-0, Λ waxy solid 3-CF3 0CH3 COOCH (CH3) CH (CH3) 2 85-88 / -CH3 - CF3 0CH3 co-1,5365 3-CF3 och3 coo 3 94-95 3-CF3 0CH3 C3-8 C3-8 CF3 0CH3 C (O) CH2C00C2H5 50-54 3-CF3 0CH3 SO2CH2C1 102-105 3- CF3 CR COO-C3 H7 93-96 3-0 * 3 0 CH3 C (S) NHCH3 3 150-154 3-CE3 0 CH3

COOCH λ 83-87 3-OF 3 0 CH 3 COOCH 2 -Q 4. 63-70 31

TABLE I (continued)

Comp. N2. R 1 or

137 3-CF3 och3 138 3-CE3 och3 137 3-CE3 och3 140 3-CE3 och3 141 3-CF3 och3 pf nD30 cooch2-84-86 C (O) NH-CH3 119-122 CH = CHC (O) CH3 79-81 c (o) n (ch3) 2 99-103 0 (° C) 79-81 142 3-CF3 och3 c (O) - ^ 89-97 143 3-CF3 n (ch3) 2 COO-i -C3 H7 57-64 3-CF3 c (o) n h2 COO-C-, c) 145 3-CF3 0 CH3 cooch2- 1.5332 146 3-cf3 0CH3 C00-t-C3 H9 113-118 / GH3 147 3-CF. OCH C (O) N 55-593 3 Nc 2H5

Comp. 148 149 150 151 152 153 154 155

(S) or a pharmaceutically acceptable salt thereof. Table I (continued) pf UC or nD50 0-3-CF3 och3 3-CF3 och3 3-CF3 och3 3-CF3 och3 3-CF3 och3 3-CF3 0CH3 3-CF3 0CH3 3-CF3 0CH3 COOCH, 0-95-91 COOCH '112-113

COO

COOCHp-1 | *

79-90.5 COOCH (CH3) COOCH3 97-99 c (o) ch2ci so2ch3 0

65-68 114-115 tb______________________________________ tb TABLE I (continued)

Comp. Δδ.

R-156 157 158 159 160 161 162 163 164 165 166 3-CF3 OGH3 3-CF3 OCH3

61-65 SO, m.p., or nD30 CO) 149-151 3-CF3 C (O) NHC3 C (O) 0- (C3H7) 196.5-200. 3-CF-O-C-OCH-OCH-C (O) -C (O) // R 0 160.3-163.6 136.2-137.9 C (O) CH 2 CH 3 61.8- 64.1 3-CF 3 (CH 3) 2 121.6-123.7 H sch 3 C (O) CH 2 CH 3 CH 3 ) 0-IC, H7 101.3-103.9 H sch3 C (O) -i-04Hg 1.6055 H sch3 C (O) NH-1-C 3H7 120.5-123.8 34 Comp.

R

TABLE I (continued)

R 1

R 2 30 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 pf or nD 3-CH3 sch3 0 (0) 0- (C3 H7) 1.6053 3-CH3 C3 (O) C4H3 oil 3-CH3 SCH3 C (O) NH-i-C3H7 74.4-79.7 3-OCH3 SCH3 C (O) NH-1-C3H7 , 9-111.5 3-CF-3-CF. 3-CF3; 4-P3-CF3; 4-F3-Cr3,4-F3-SCH3 3-SCH3 3-01,4-F3-Cl, 4-F3-01,4- CF3 3-SCH-, SCH- SCH- sch3 sch3 sch3 sch3 sch3 sch3 sch3 SCH3 S (O) CH: OCH-,

C (O) OCH3,

C (O) 0-i-C3 H7 C (O) -i-C4 Hg C (O) NH (i) -O-C 3 H 7 C (O) -i-C 4 H 9 O (O) 0-i-C 3 H 7 100.6-107.8 72.6 - 75.8 105.5-107.7 42.9-51.0 135.8- 136.5 1.5275 semi-solid 110.8- 112.8 52.6-55.9 81.3-92.8 86.2 -92.1 1.5436 35

TABLE I (continued)

Comp. N 184 184 185 186 187 188 189 190 191 192 193 194 195 196 p CR CR CR CR ou ou ou ou ou ou ou ou ou ou ou ou ou ou ou ou ou ou ou ou ou ou ou ou ou ou ou ou ou ou ou ou 49 49 49 49 49 49 -OCH3 O (O) O-C3 H7 127.3-129.0 0 3-01.4 -? 0CH3 3-S02CH3 0CH3 3-ΟΙ · 3> 4-Ρ och3 3-CF3 | 4-P 0CH3 3-cf3 | 4-f 0CH3 C (0) 0

(o) o-C3 H7 O (o) o-C3 H7 O (o) C (O) -i-C4 H5 O

125.9-127.4 144-, 5-146.2 98.6-101.0 54.9-58.0106,1-109.8 -Ο (Ο) - [3 - [(3 -CH 3 -OCH 3 -O-CH 3 -O-CH 3 -O CH 3 -O CH 3 -O-C 3 H 7 3 -OCH 2 CH 2 -C (O) O-C 3 H 7 1.5485 / (0) -? 79.7-82.8 3-OCF2CF2H-SO2 H3 -C (O) O-i-C3 H7 82.5-85.7 3-OCF2 CF2 H -SCH3 -C (O) C4Hg 57.4-62.9 Ί ϊ 36

5 TABLE I (continued)

Comp. NS 3 R 3 R 3 R 3 R 3 R 3 R 3 R 3 R 3 R 3 R 3 R 2 R 3 R 3 R 3 R 3 R 3 R 3 -OCH 3 206 3-CF3-4-F -OCH3 205 3-CF3-4-F -OCH3 206 3-CF3 -OC3 O2 or C0-30 -O (O) O-C3 H7 88.6-89, 4-C (O) -i-C4 Hg 81.4-83.8 -c (o) -i-C4 H9 50.0-51.8 -c (o) -? 1.5410 -c (O) ) -] <80.9-90.6 CH3 -c (0) <1 1.5330 CH3 -c (0) <] 99.7-102.4 -C (°) <1 108-9-111.4 ^ 3 -c (0) <1 89.6-92.2 CH3 -c (0) <] 79.7-81.8 CH3

TABLE I (continued)

Oomp. m.p. 95 ° C R9 · R¹ R² or -C (O) - <1 1.5524 ° C -C (O) 0C2H5 88.4-92.5 -C (O) C3H7 semi-solid

207 3-CF 3 -oc-3 3 3 CF 3 -oc 2h 2 209 3-CP 3 -oc 2h 5 210 3-CP 3 -oc 2h 5 211 3-CF 3 -oc 2h 212 3-CF 3 H -C (O)

Produced as a blend due to the mixture of isomers in the starting materials.

Intermediates of Iminothiadiazole 213 214 215 3-CP3CH3 hydrochloride of compound N5. 191 3-CF-SCH-hydrobromide 72, -73.5 144-145 22.3-224.2

Herbicidal evaluation

The compounds of Table I above were tested for herbicidal activity as follows.

Prior choice pre-emergence herbicide test

Trays were loaded with sandy-clay soil containing a fungicide and a fertilizer. The soil was ground and three grass weeds, three broad leaf weeds and cypress weeds (Cyperus esculentus) were planted sufficiently thick to sprout several stakes per cm of rego. The grass weeds were as follows: Green Mill (Setaria viridis), Million-foot Rooster (Echino-chloa crusgali) and Dove Oats (Avena fatua). The broad leaf weeds used were ipomeia (Ipomoea purpurea), Chinese hemp (Abutilon theophrasti) and wild mustard (Brassica kaber).

Solutions of the test compounds were made by weighing 333 mg of the subject compound in a flask and dissolving in 25 ml of acetone containing 1% polyoxyethylene sorbitan monolaurate emulsifier to form a storage solution. Additional solvents not exceeding 5 ml were used where necessary to dissolve the compound. An aliquot of the stock solution was withdrawn and diluted with a 19: 1 mixture of water: acetone containing 1% emulsifier to form a sprayable solution.

The trays were placed in a plant oven at 21.1 - 29.5 ° C and were sprinkled with spray. One day after planting the trays were sprayed with the solutions of the test compounds at a rate of 304 liters of solution per hectare, the compound being applied at a rate of 4.48 kg / ha.

The trays were put back into the greenhouse after being sprayed and watered daily by spray. The degree of weed control was determined and recorded 3 weeks after treatment as percent control compared to the growth of the same species in an untreated comparison tray at the same age. Percent control is based on total damage to plants due to all factors including inhibited germination, destruction of plant tissue after emergence, burning, malformation, chlorosis and other types of damage. Control rates range from 0 to 100 percent, where 0 represents absence of effect with equal growth for the untreated control and 100 percent represents complete destruction.

Post-emergence herbicidal evaluation

The soil was prepared and seeded with the same varieties as described for the pre-emergence test. The trays were placed in the greenhouse for plants at 21.1-29.5 ° C, and watered by spray. Twelve to fourteen days after planting the trays were sprayed on a table at a rate of 304 l of solution per hectare. The compound was applied at the rate of 4.48 kg / ha. The spray solution was similar to that described for the pre-emergence evaluation.

The trays were put back into the greenhouse after being sprayed and watered daily without wetting the foliage. Three weeks after treatment the degree of weed control was evaluated as percentage control compared to the growth of the same species on an untreated comparison tray of the same age. The percentage control rates were allocated on the same basis as for the pre-emergency assessment. 40

The following Table II contains the results of these tests in terms of average control of the three grasses and the three broadleaf weeds, respectively, in the pre-emergence and post-emergence evaluations. Control of the broiler is not included in this table for convenience, since most of the compounds did not show any control or almost no control of the broiler in these tests. Some compounds, however, in particular the Compounds 70, 71, 72, 76, 79, 80, 129, 130, 132, 138, 141, 150, 155, 156, 161, 162, 172, 173, 185, 186, 188, 189 and 190 showed no activity against the juniper.

It should be noted that even the compounds which (from the following table) indicate a relatively low average control of weeds, however, showed good activity against at least one weed in these tests, which in many cases was mustard .

TABLE II C omp. Pre-emptive control (mean) Post-emergence control (mean) N2 · grasses broad-leaf grasses broad-leaf 1 23 43 10 53 2 30 73 20 83 3 28 0 27 47 4 28 82 7 65 5 23 67 10 72 6 0 42 - - 7 73 73 50 78

Comp. NS. 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 TABLE Pre-(average) control kH II (continuation) -emergency Post-emergence L (control) grasses broad-leaf grasses broad-leaf 7 63 30 63 0 37 3 55 2 48 13 73 2 42 13 57 42 85 27 63 20 32 2 23 17 30 2 22 27 35 2 25 33 47 5 25 47 73 13 25 93 83 38 50 95 97 68 60 95 80 70 93 93 50 57 93 47 60 67 92 77 65 80 90 63 60 67 93 63 67 73 90 87 63 73 93 90 67 73 92 75 63 63 67 53 37 37 93 95 73 73

Comp. NB. 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55

TABLE II (continued)

Pre-emergence control Post-emergence control (mean) (average) _ Comp. grasses broad leaf grasses broad leaf NS. 56 97 47 27 60 57 97 85 78 93 58 90 85 23 90 59 45 22 10 40 60 60 42 20 60 61 35 10 13 50 62 72 37 13 50 63 93 67 65 87 64 87 75 43 77 65 73 37 13 30 66 43 33 2 13 67 83 57 27 67 68 88 57 43 60 69 80 28 7 27 70 100 100 88 80 71 98 100 83 80 72 98 100 85 80 73 100 100 87 57 74 100 100 85 80 75 100 100 87 80 76 100 100 87 83 77 98 100 87 80 78 98 100 77 83 79 98 100 85 83 80 98 97 80 80 44 TABLE II (continued) Pre-emergency control Post control -emergen- Comp. (mean) cia (mean) δ. grasses wide leaf grasses wide leaf 81 70 93 60 77 82 83 88 72 70 83 88 82 73 87 84 100 100. 83 83 85 98 100 87 83 86 98 100 80 83 87 72 90 57 80 88 75 92 47 73 89 88 83 53 73 90 95 95 60 73 91 95 92 67 73 92 97 100 87 73 93 93 92 60 60 · 94 75 63 47 53 95 97 97 72 73 96 95 97 80 73! 97 80 63 60 47 98 97 97 70 73 99 85 90 33 73 100 97 100 73 80 101 97 98 80 83 102 98 100 83 80 103 98 100 80 80 104 100 98 80 80 105 98 100 82 80 45

Comp. N2. Control TABLE II (pre-emergence (average) ontinuation) Control of (post-emergence day) grasses broad-leaf grasses broad-leaf 106 98 100 82 80 107 100 100 82 80 108 98 100 80 80 109 82 98 33 80 110 97 97 80 75 111 98 100 33 87 112 83 82 27 80 113 95 87 57 80 114 95 100 40 80 115 100 83 67 67 116 100 100 88 87 117 100 100 87 87 118 100 100 87 80 119 100 100 92 90 120 100 63 43 67 121 97 78 85 60 122 20 75 0 90 123 5 8 2 53 124 80 100 70 97 125 98 100 93 70 126 98 100 97 100 127 93 100 53 50 128 97 100 87 88 129 100 100 87 87 130 95 100 95 95

Comp. TABLE II (continued) Pre-emergence control Post-emergence control (mean) (mean) grasses broad-leaf grasses broad-leaf N2. 131 85 40 73 67 132 100 100 98 93 133 50 67 27 77 134 50 30 10 40 138 100 100 87 57 139 97 92 60 73 140 70 100 80 90 141 100 100 87 90 142 100 100 87 87 143 95 97 73 73 144 87 92 83 80 145 77 63 63 68 146 95 100 68 100 150 100 100 100 100 151 50 73 47 60 152 97 70 53 92 153 70 100 73 63 154 67 43 20 0 155 47 70 60 70 156 97 100 80 87 157 73 100 87 90 158 40 40 7 58 159 77 40 3 33 160 100 80 23 87 161 100 100 97 100

Comp. Δδ. TABLE Pre-control (average) II (continued) -emergence Post-control (mean) -emergen- grasses broad-leaf grasses broad-leaf 162 100 100 100 100 163 98 100 67 60 164 97 40 37 33 165 100 58 60 50 166 73 63 37 40 167 97 47 77 57 168 100 67 57 73 169 93 80 60 82 170 100 63 30 10 171 93 80 33 23 172 100 83 80 93 173 100 93 80 97 174 100 100 100 100 175 100 100 100 100 176 97 95 100 82 177 83 73 75 60 178 70 45 73 73 179 73 50 67 53 180 87 93 90 53 181 83 93 80 60 182 80 70 83 87 183 100 93 88 83 184 100 100 93 97 185 100 100 93 100 186 100 100 97 97 48 48 «

TABLE II (continued)

Comp. N2. Pre-emptive control (average) Control of post-emergence emergence- broad-leaf grasses broad-leaf 187 95 100 93 83 188 100 100 93 83 189 100 '100 88 80 190 100 100 87 80 191 43 73 0 60 192 * 100 98 98 85 193 * a 100 100 93 97 194 * 70 87 30 53 195 * 50 47 0 37 196 * 93 100 67 87 197 * 97 100 47 70 198 * 93 100 80 80 199 * 100 100 95 93 200 * 100 100 63 90 201 * 100 67 50 80 202 * 100 100 100 97 203 * 100 100 100 80 204 * 100 100 78 80 205 * 100 100 100 90 206 * 100 100 98 95 a Reg this 18 days after treatment 207 * 100 100 100 63 208 100 63 53 33 209 100 93 93 93 210 60 80 40 37 211 100 100 90 83

ΤΑΒΞΒΑ II (cont'd)

Pre-emergency control Post-emergency control Comp. _ (average) _ _ (average) _ N9. grasses broad leaf grasses wide leaf 212 98 85 77 93 213 95 67 47 67 214 95 87 73 83 215 70 33 30 10 *

Treatment = 2.24 kg / hectare.

Subsequent herbicidal evaluation

Compounds which showed good activity in the above-described evaluations were subjected to one or more subsequent evaluations involving, for example, different weeds, lower application rates, varying application procedures and / or selectivity for cultures. The weeds used in these tests include those used in the tests described above, as well as a number of others such as one or more species of fake rye (Lolium), Sorghum, Brachiaria (Brachiaria), Thistle (Xanthium), Sesbania, Cassia, Alopecurus , oat (Avena), field grass (Poa), Matricaria, chickweed (Stellaria), gallium (Galium) and violet (Viola). The crops that were used in a variety of ways in these assessments included cotton (Gossypium hirsutum), soy (Glycine max), maize (Zea maize), millet (Sorghum bicolor), wheat (Tritium aestivum), sugar beet garis), rice (Oryza sativa), carrot (Daucus carota) and barley (Hordeum vulgare).

Summarizing, the compounds undergoing further evaluation revealed

activity varies depending on the compound and the evaluation employed. Some compounds have shown improved control activity of grasses, others in the control of broadleaf weeds. Some compounds demonstrated a better activity in the pre-emergence application, others in the post-emergence application. Some compounds have demonstrated good activity in almost all types of application. Some compounds have demonstrated good control in the tests with application rates ranging from 0.065 kg / ha.

With regard to crop damage, almost all of the tested compounds produced unacceptable damage to sugar beet even at relatively low application levels. Some compounds showed good broad spectrum activity but relatively low selectivity, causing damage to weeds and crops in the same tests. Other compounds showed a variation of activity in certain crops, in particular in cereals, such as wheat, rice and maize, which is of higher note for rice in various application methods. A number of compounds also demonstrated a selectivity in weed control in the presence of cotton. In practice, a pure compound can be used as a herbicide. However, in general, the compounds are first formulated with one or more inert carriers or diluents suitable for herbicidal use prior to application.

The compositions or formulations, including the compound as described herein, may exist in any of the solid or liquid forms. Examples of solid forms are powders, granules, lozenges, powders and the like. Examples of liquid forms are emulsifiable, slippery concentrates and pastes. Such compositions may contain, in addition to the active compound or compounds, various carriers or diluents; surface active agents (wetting agents, dispersing agents and / or emulsifying agents); solvents (water, or organic solvents, such as aromatic solvents or chlorinated aliphatic solvents); thickening tackifying agents; binders; antifoaming agents; and other substances such as those mentioned herein. The carrier agents or solid diluents included in such compositions or formulations may include, for example, ground natural minerals such as kaolins, alumina, calcium carbonate, silica, diatomaceous earth, clay, etc .; milled synthetic minerals such as various silicates and aluminosilicates and ground vegetable products such as cork, fuba, sawdust, cellulose powder and the like.

To produce the solid compositions, the active substances are mixed with carriers or solid diluents such as those mentioned above and the blend is milled to the appropriate granulometry. The granules may be produced by dissolving an active compound in an organic solvent and applying the mixture, for example, by spraying onto an absorbent granular inert material such as silica. Adhesive agents may be used to aid in the incorporation of the compound into the solid particles. &Quot; pellets &quot; or granules can be produced by extrusion with suitable carrier agents and binders.

Wettable powders, slides and pastes are obtained by blending and milling an active compound with one or more dispersing agents and / or carriers or solid diluents. Wetting agents and / or dispersing agents may also be included, for example, lignins, methyl cellulose, naphthalenesulfonic acid derivatives, fatty alcohol sulfates and various types of alkali and alkaline earth metal salts of fatty acids.

Emulsifiable concentrates are generally obtained by dissolving the active compound in an organic solvent, e.g.

butanol, cyclohexanone, xylenes, or high boiling aromatic hydrocarbons. In order to obtain suspensions or emulsions in water, wetting agents are generally added. It is possible to use highly concentrated liquid compositions containing up to about 95 wt.% Of the active compound, or even the active compound alone for those compounds which are liquid when the compound is applied as a finely divided liquid using various spray equipment, e.g. by crop spraying techniques, by airplane. For other purposes, however, the various types of compositions that may be used for these compounds may contain varying amounts of the compound, according to the type of composition and intended use.

In general, the compositions may contain from 0.1 to 95% active compound, more preferably from 0.5 to 90%. Some with typical positions may contain an active compound as follows: wettable powders, slides and slurries - 20 to 90%. of active compound; oil suspensions, emulsions, solutions and emulsifiable concentrates - from 5 to 90% active compound; aqueous suspensions - 10 to 50 ml of active compound; powders and powders - .1 to 25 active compound; granules and T, pellets &quot; -1 to 20% active compound. The rate of application of the active compound to a site to be controlled will depend on the activity of the compound and / or composition and the nature of the seeds and plants and be controlled and may vary from about 0.06 to about 56 kg / ha.

In addition to the active compound and the various agents used in the preparation of the above-mentioned compositions and formulations such compositions may also contain one or more other active compounds of the type mentioned herein, as well as other pesticidal agents such as herbicides, fungicides, insecticides , acaricides, nematocides, bactericides and plant growth regulators. Such compositions may also contain

soil disinfectants or fumigants and may further contain fertilizers, thereby making it possible to provide multipurpose compositions containing one or more of the compounds described herein, as well as optionally other pesticides and also all fertilizers with the intent and formulated to be used in the same place.

Compositions containing one or more of the active compounds described in a herbicidally effective amount may be applied to the plant or site to be controlled, in any conventional manner. Thus, the powders and the various liquid compositions containing the active compound may be applied using powder dusters, hand and arm sprayers, and spray sprays, or be applied from airplanes such as vapors or sprays. When applied by the latter method, they may be effective at very low dosages. To modify or control the growth of germinating seeds or cuttings, the liquid compositions may be applied to the soil by conventional methods and may be distributed in the soil to a depth of 1.27 cm below the soil surface. The compositions do not need to mix with the soil particles and can be applied only by spray to the soil surface.

The compositions which comprise the active compounds may also be applied by adding to the irrigation water supplied to the field to be treated. This method of application allows the penetration of the compounds into the soil as the water is absorbed by the same. 54

EXAMPLES OF TYPICAL COMPOSITIONS Oil

Ingredient Active compound Solvent in heavy aromatic naphtha oil Total

Weight 1 99 100

Emulsifiable concentrate

Active compound 50

Kerosene 45

Emulsifying agent (mixture of long chain ethoxylated polyolethers with long chain sulfonate)

Total 100

Emulsifiable concentrate 90

Active compound

Kerosene 5

Emulsifier (blend of long chain ethoxylated polyolethers with long chain sulfonate) Total 5 100 Powders and / or Powders Ingredient Weight% Weight ic Weight% Active compound 0.5 50.0 90.0 Lactic acid powder atapulgite Lignin- sulfonate 93.5 44.0 4.0 sodium 5.0 5.0 5.0 Sodium dioctyl sulfosuccinate 1- (O-1-1 O 1-1 Total 100.0 100.0 100.0

Claims (2)

55 THE A process for the preparation of substituted 2- (imino) -1,3,4-dihydrothiadiazoles of formula (I) Wherein R1 is halogen, trihalomethyl, pentahalo-ethyl, monoofluoromethyl, difluoromethyl, monofluoroethyl, difluoroethyl, trifluoromethyl, tetrafluoroethyl, fluoroalkylthio, fluoroalkoxy, methylthio, methylsulfonyl, halomethylsulfonyl, -C (O) n is 0, 1 or 2, with the proviso that: a) if n is 1 and R is other than fluorine, the R 3 substituent is at the 3-position of the phenyl ring; and b) if n is 2, the substituents R are situated at the 3- and 4-positions of the phenyl ring; R3 is hydrogen, C1 -C6 alkyl, C1 -C4 alkoxy in C1-4 alkylthio, C2 -C4 alkenylthio, C1 -C4 alkylsulfonyl, C1 -C4 alkylsulfinyl, cyano, carbamyl, monoalkylcarbamoyl, C 1 -C 2 -alkoxycarbonyl or NR 2 -C 3 -alkyl, wherein R 1 and R 2 are independently hydrogen, C 1 -C 4 -alkyl or alkenyl in; and R8 is hydrogen; phenyl; monosubstituted phenyl or phenyl wherein the substituents are selected from halogen, cyano, and trihalomethyl; C1 -C4 monoalkyl, or C1 -C4 dialkylcarbamyl; phenylcarbamyl; C 1 -C 4 -monoalkylthiocarbamyl; C -C-C--ketoalkenyl; cyano; C 1 -C 4 -alkylsulfonyl; C 1 -C 4 haloalkylsulfonyl; or O- (Y) m -R5 wherein Y is oxygen or sulfur; m is 0 or 1; and R3 is C1 -C4 alkyl; and (c) C1 -C6 alkenyl wherein n is 0; C 1 -C 6 -alkynyl wherein the triple bond is separated from the oxygen or sulfur atom (Y) by at least one methylene group if m is 1; halo-C1-6 alkyl, if m is 0; C2-C8-halogenalkyl, if m is 1; C 2 -C 10 -alkoxyalkyl, where m is 0; pyridyl, if m is 0; alkoxyalkyl in which the alkylene group has at least two carbon atoms, if m is 1; or e (R6> pR7 wherein R10 is hydrogen, C1-6 alkylene and R5 is phenyl, halogen substituted phenyl, C1-6 cycloalkyl optionally substituted by 1 to 3 methyl groups; or a 5- or 6-membered saturated or unsaturated heterocyclic ring comprising 1 to 2 heteroatoms selected from oxygen and sulfur, optionally substituted by 1 to 3 methyl groups and optionally substituted by 1 or 2 oxo groups; (a) for the preparation of a compound of formula (I) wherein R 2 is hydrogen and R 2 is other than alkylsulfinyl or alkylsulphonyl, and R 2 is reacting a compound of formula 57 with cyanogen chloride or cyanogen bromide; or b) for the preparation of a hydrohalide salt of a compound of formula (I), wherein it is hydrogen and is other than alkylsulfinyl and alkylsulfonyl, if a compound of formula with cyanogen halide or cyanogen bromide, in the presence of a base; or (c) for the preparation of a compound of formula (I), with the exception of those in which it is hydrogen, phenyl or substituted phenyl, or wherein R4 is alkylsulfinyl or alkylsulphonyl, A) reacting a compound of formula formula 58 With cyanogen chloride or cyanogen bromide, optionally in the presence of a base; and B) the product of step (A) is reacted with an acylating agent selected from the group consisting of compounds of formula wherein Z 'is a halogen, isocyanates and isothiocyanates of the formula Rg-NCO or RgNCS wherein R8 is C1 -C4 alkyl or phenyl; or for the preparation of a compound of formula (I) with the exception of those in which R é is hydrogen or wherein R é is alkylsulfinyl or alkylsulfonyl, a compound of formula with an imidoyl halide of the formula Hal V = N-R, wherein Hal is halogen, in the presence of a base 2a. 2. A process according to claim 1 wherein n is 1; R is substituted on the phenyl ring at 59 position in C-C the R-, 3; C 1 -C 4 alkoxy, C 1 -C 4 alkoxy, C 1 -C 4 alkylthio, or NR 1 R 2 wherein R 2 is hydrogen or both R 4 and R 5 are C 1 -C 4 alkyl or R 2 is C1-4 alkylsulfonyl. 3â. 2. A process according to claim 1, wherein R 2 is -C (Y) -R c m 5 wherein m is 0, R 2 is (Rg) p R 2 wherein p = 0, R 1 'is C 1 -cycloalkyl -G3, optionally substituted by 1 to 3 methyl, phenyl, substituted phenyl or C1 -C4 -alkoxy groups, or R3 is a saturated or unsaturated 5- or 6-membered heterocyclic ring, including 1 to 2 heteroatoms selected from oxygen and sulfur, optionally substituted by 1 to 3 methyl groups and optionally 1 to 2 oxo groups. 4â. 6. A process according to claim 3, wherein m is 0; R ser is C--C alquilo alkyl, C al-C al alkenyl; 2-C10 'halo isothioalkyl in C 1 -C 8 or C 2 -C 10 -alkoxy. A process for the preparation of a herbicidal composition comprising (a) a herbicidally effective amount of a compound of formula (I) prepared according to any one of claims 1 to 4; with b) a herbicidally suitable diluent or carrier. 60 60 ?? Λ srâ 6β. A method for controlling the presence of undesired vegetation characterized in that a herbicidally effective amount of a compound of formula (I) prepared according to any one of the preceding claims is applied to said vegetation or to the place where control is desired. Claims 1 to 4, preferably from about 0.06 to about 56 kilograms per hectare. 7â. A method for controlling the presence of undesirable vegetation, characterized in that a herbicidally effective amount of a composition according to claim 5 is applied to said vegetation or to the place where control is desired. A process for the preparation of a thionohydrazine of formula (II) in which R is halogen, trihalomethyl, pentahalogenoethyl, mono-fluoromethyl or difluoromethyl, mono-fluoroethyl, difluorothioyl, trifluoromethyl or tetrafluoroethyl, fluoralkylthio, fluoro-methoxy, methylthio, methylsulfonyl, halomethylsulfonyl, -C2 or methoxy; n is 0, 1 or 2, with the proviso that: (a) if n is 1 and R is other than fluoro, the substituent R is situated at the 3-position of the phenyl ring; and (b) if n is 2, the substituents R are situated at the 3- and 4-positions of the phenyl ring; and R3 is (C1 -C2) alkyl, (C1 -C2) alkoxy; C 1 -C 6 alkenylthio, C 2 -C 6 carboalkoxy, cyano, carbamoyl, C 1 -C 4 -alkylalkylcarbamyl or NR 2 R 3 wherein R 2 and R 3 are independently hydrogen, C 1 -C 4 alkyl or alkenyl group as the starting material for the process according to claim 1, characterized in that a) for the preparation of thionohydrazines of formula (II) in which R 1 is alkylthio or alkenylthio, a phenylhydrazine with carbon disulfide in the presence of a base or an alkylating agent; b) for the preparation of thionohydrazines of formula (II) wherein R1 is alkoxy, an appropriate substituted phenylhydrazine is reacted with a dithiocarbonate in which R1 is C1 -C4 alkoxy and Rg is an alkyl or methylcarboxy group; c) for the preparation of thionohydrazines of formula (II) wherein R1 is a C1 -C4 alkyl group, an appropriate substituted phenylhydrazine is reacted with phosphorus pentasulfide in the presence of a solvent inert; or (d) for the preparation of thionohydrazines of formula (II) wherein R1 is NR2 R3, a thionohydrazine in which R3 is thioalkyl is reacted with an appropriate amine. Lisbon, July 22, 1988. The Official Agent of Industrial Property, A-, /............. 1P00 LISBOA