EP0252982A1 - Herbicidal 1-aryl-4-sustitutted-1,4-dihydro-5h-tetrazol-5-ones and sulfur analogs thereof - Google Patents

Abstract

Described are herbicidal compounds of formula (I) wherein Z is a substituted sulfonylamino group or a salt of this group, X1 represents fluorine or chlorine, X2 represents chlorine or bromine, and R is trifluoromethylthio or alkenyl or substituted or unsubstituted alkyl; also described are intermediates and methods for producing the herbicidal compounds, as well as compositions containing the herbicidal compounds and a method of using the compositions.

Description

HERBICIDAL 1-ARYL-4-SUBSTITUTED-1,4-DIHYDRO-5H-TETRAZOL-5-ONES AND SULFUR ANALOGS THEREOF

This invention concerns novel selective herbicides.

PCT International application no. WO 85/01939 published May 9, 1985 discloses various herbicidal compounds of the formula

most preferably those in which W is oxygen, R is

3-fluoropropyl, X¹ is fluorine and X² is chlorine.

According to that published application Z may be N(R¹⁴)(R¹⁵) in which R¹⁴ and R¹⁵ are independently selected from a list including hydrogen and alkylsulfonyl (preferably of 1 to 4 carbon atoms), being for example NHSO₂CH₃.

The present invention provides herbicidal compounds including the compound of the formula

which is a particularly effective selective herbicide especially for pre-emergent use on such crops as soybeans, corn, barley, wheat, rice (e.g. paddy rice), beans, peas, peanuts and potatoes. It is effective at low rates, e.g. at about 0.5 kg/ha and below, such as rates of 0.375, 0.25, 0.1 or 0.06 kg/ha and even lower, such as 0.015 kg/ha. Its effectiveness is indicated by the data in Table A, below comparing compounds nos. 2 and 4 (of Table 1 below) in tests using pre-emergence application at a rate of 0.0156 kg/ha. (Note: In Table A below, the numbers indicate the percent control (an average of two replications) of the particular plant species in the greenhouse, using the testing technique described in the above-mentioned PCT patent application.) Table A

Compound Compound

4 [ethyl] 2 [methyl]

Soybean (Glycine max) 0 0 Corn (Zea mays) 0 0 Morningglory (Ipomea spp.) 45 0 Pitted Morningglory 10 0 Jimsonweed (Datura stramoniam) 60 40

Wildmustard (Brassica kaber) 100 65 Sesbania (Sesbania exaltata) 80 25 Prickly Sida (Sida apinosa) 85 20

Velvetleaf (Abutilon theophrasti) 100 60

At the low rates mentioned above the compound is particularly useful in combination with other herbicides such as 2-[(2-chlorophenyl)methyl]-4,4-dimethyl-3-isoxazolidone, trifluralin (i.e. N,N-dipropyl-alpha, alpha, alpha-trifluoro-2,6-dinitro-p-toluidine), tridiphane (i.e. 2-(3,5-dichlorophenyl)-2-(2,2,2-trichloroethyl)oxirane), alachlor (i.e. 2-chloro-2',6'-diethyl-N-(methoxymethyl)acetanilide) or any of the following: isoproturon bentozon chlortoluron acifluorfen-sodium clopyralid chlorpropham bromoxynil imazaquin pyridate 2,4-DB bifenox paraquat chlorsulfuron glyphosate dichlofop-methyl vernolate difenzoquat chlorimuron dicamba atrazine dinoseb cyanozine triallote simazine barban EPTC

2,4-D esters butylate

2,4-D amine salts propanil terbutryne molinate flamprop-isopropyl oxadiazon propachlor butachϊor metolachlor pyrazolate chloramben thiobencarb linuron napropamide tri fluralin oryzalin pendimetholin

The pre-emergence application of the tetrazolinone herbicide may be combined with a sequential, post-emergent treatment with another herbicide such as one of the known grass-controlling herbicides which show a favorable selectivity for the particular crop. Such post-emergence treatment may be made, say, one or two weeks or more (e.g. a month) after the emergence of the crop. Herbicides that may thus be applied sequentially in combination with the pre-emergence application of the tetrazolinone include such materials as the ethyl ester of 2-(4-((6-chloro-2-quinoxalinyl)oxy)phenoxy)-propionic acid; sethoxydim; haloxyfop-methyl; and quinofop-ethyl.

In one series of tests, compositions for pre-emergence application were formulated by mixing Aqueous Suspension A (described below) with Flowable Concentrate B (also described below) and water, the relative proportions and rates of application being such that the active ingredients were applied at rates shown in Table B, below, to the field planted with soybeans:

Table B

Active Ingredient (in Kg/ha)

Mixture No. A B

1 0.063 0.28

2 0.125 0.28

3 0.25 0.28

4 0.50 0.28

5 0.063 0.56

6 0.125 0.56

7 0.25 0.56

8 0.50 0.56

9 0.063 0.84

10 0.125 0.84

11 0.25 0.84

12 0.50 0.84

In each case very good control of both broadleafed and grassy weeds was obtained with no damage (or at most minimal damage) to the crop. Aqueous Suspension A % by Wt.

Active ingredient A (Compound No. 4) 4.92

Antimicrobial agent 0.05

Foam suppressant 0.10 Surfactant C 2.60

Surfactant D 0.40

Thickener 0.35

Suspending agent 0.45

Propylene glycol (antifreeze) 6.00 Water 85.13

Total 100.00

The antimicrobial agent is sodium o-phenylphenate tetrahydrate sold under the trademark and designation "Dowacide A". The foam suppressant is a water dilutable silicone emulsion sold under the trademark and designation "Dow Corning AF". Surfactant C i s a non-ionic paste of a condensate of ethylene oxide with a hydrophobic base formed by condensing propylene oxide with propylene glycol, sold under the trademark and designation "Pluronic P-84." Surfactant D is an anionic liquid comprising the sodium salt of a complex organic phosphate ester, sold under the trademark and designation "GAFAC LO-529." The thickener is a xantham gum sold under the trademark and designation "Kelzan-M". The suspending agent is a colloidal magnesium aluminum silicate sold under the trademark and designation "Veegum." To prepare this Suspension A, all the ingredients, except the thickener and some 4/10 of the total water, are ground together after which the thickener and the balance of the water are added.

Flowable Concentrate B

Active ingredient B* 64.3% Inert solvent plus minor amount of emulsifier 35.7% Active ingredient B is 2-(2-chloroρhenyl)methyl-4,4-dimethyl-3-isoxazolidinone

It has also been found that the compound of the formula

is a highly selective herbicide for use with cotton or soybeans particularly for preemergence application at rates below about 1/4 or 1/10 kg/ha (such as rates of 0.06, 0.03 or 0.015 kg/ha). Its effectiveness is indicated by the following data for percent control on preemergence application of the compound at a rate of 0.0313 kg/ha in the greenhouse. Plant Species % Control

Cotton (Gossypium hirsutum) 0

Soybean (Glycine max) 0

Corn (Zea mays) 90

Rice (Oryza sativa) 80 Wheat (Triticum aestiuium) 90

Nightshade (Solanum spp.) 100

Sesbania (Sesbania exaltata) 100

Velvetleaf (AbutiIon theophrasti) 100

Barnyardgrass (Echinochloa crus-galli) 60 Large Crabgrass (Digitaria sanguinalis) 100 Green Foxtail (Setaria viridis) 90

Johnsongrass (Sorghum halepense) 90

Proso Millet (Panicum miliaceum) 90 The sulfonamides disclosed herein which have a hydrogen on the nitrogen of the sulfonamide group are acids and, as taught in the published PCT International application no. WO 85/01939 may be converted into a salt such as a sodium, potassium, calcium, ammonium, magnesium or mon-, di- or tri(C₁ to C₄) alkyl ammonium salt which may also be used, in that form, as the herbicide. Other suitable herbicidal salts of these sulfonamides are the sulfonium or sulfoxonium salts, such as salts of bases of the formula

R"₃S(O) where R" is, for instance, lower alkyl (e.g. C₁-C₃ alkyl) and n is zero or one, e.g. the trimethylsulfoxonium salt.

The various sulfonamides discussed herein may be described as those in which Z (in formula I above) is

N(R³¹)SO₂R³⁰' wherein R³⁰ may be alkyl (such as straight chain or branched chain lower alkyl, e.g. methyl, ethyl, propyl), haloalkyl (such as CF₃ or

CHF₂), dialkylamino, aryl (such as phenyl, optionally substituted with one or more of: halogen such as Cl, Br or F; alkyl such as lower alkyl, e.g. methyl; alkoxy such as lower alkoxy; e.g. methoxy; cyano; cyanomethyl; nitro; amino; arylamino such as phenylamino; mono- and dialkylamino such as methylamino or dimethylamino; carboxyl; alkoxycarbonyl such as -COOC₂H₅; alkoxy- alkyl such as alkoxymethyl of 2 to 4 carbon atoms; alkoxycarbonylalkyl such as -CH₂COOC₂H₅; benzyl; or hydroxy). R 31 may be hydrogen, alkyl (e.g. straight or branched chain lower alkyl such as methyl, ethyl, propyl, isopropyl or butyl), benzyl, haloalkyl (e.g.

CHF₂ or CH₂CH₂CH₂F), alkoxy (e.g. methoxy),

SO₂R³⁰, alkynyl (such as propargyl), alkenyl (such as allyl), a group of the formula -alkylene-SO₂R ³⁰ (in which, for example, said alkylene group (e.g. -CH₂-) has 1 to 4 carbon atoms, alkoxymethyl (such as methoxymethyl), cyanpmethyl, carboxymethyl (including salts thereof) or alkoxycarbonylmethyl. R³⁰ and R³¹ together may be a divalent radical such as alkylene (e.g. of 1 to 10 carbon atoms such as methylene or 1,3-propylene). R³¹ may also be a salt-forming group such as a metal (e.g. Na, K or Ca) or ammonium (e.g. NH₄ or lower alkyl-substituted ammonium) or sulfonium or sulfoxonium, as previously discussed.

R may be alkyl (preferably of 1 to 6 carbon atoms), haloalkyl (preferably of 1 to 5 carbon atoms), alkoxyalkyl (preferably of 2 to 6 carbon atoms), alkylthioalkyl (preferably of 2 to 6 carbon atoms), cyanoalkyl (preferably of 1 to 5 alkyl carbon atoms), haloalkoxyalkyl (preferably of 2 to 6 carbon atoms), trifluoromethylthio, alkenyl (preferably of 2 to 5 carbon atoms), or haloalkenyl (preferably of 2 to 5 carbon atoms). In each aspect of the invention, it is often preferable that any alkyl, alkenyl, alkynyl or alkylene radical have less than 6 carbon atoms; and that X¹ be

F or Cl and X² be Cl or Br. The compounds in which Z is N(R³¹)SO₂R³⁰ may be prepared by the use of steps generally described in the literature or in the following Examples or by methods analogous or similar thereto and within the skill of the art. In Example I below an arylamine is treated to form the corresponding aryl isocyanate whose isocyanate portion is then modified to form a tetrazolinone ring. Thereafter the benzene ring of the intermediate is nitrated, the nitro group is reduced to form an amino group, which is then treated with R³⁰SO₂Cl or (R³⁰SO₂)₂O to convert it to an -N(R³¹)SO₂R group (e.g. by carrying out the reaction in the presence of a weak base such as pyridine or NaHCO₃) or to an -N(SO₂R³⁰) ₂ group. The compound having the -N(SO₂R ³⁰)₂ group may then be treated (as with a base such as NaOH) to form the corresponding

-NR ³¹SO₃R³⁰ group, where R³¹ is a salt-forming group (e.g. Na); this may then be treated with an acid to form the corresponding (acidic) -NHSO₂R ³⁰ group. In one embodiment, subsequent alkylation (as by treatment with the appropriate alkyl iodide as in

Example VI) forms the corresponding R³⁰ group. When the reaction sequence involves R ³⁰SO₂Cl treatment of an intermediate having hydrogen on the 4-nitrogen of the tetrazolinone ring, that hydrogen may also be replaced, during such treatment, by R ³⁰SO₂- to form an intermediate (such as a compound which has three R ³⁰SO₂- groups) from which the R³⁰SO₂- group on said 4-nitrogen may be removed readily by the treatment with the base, after which the appropriate R group may be substituted on said 4-nitrogen. The sequence of steps may be changed. For instance one may start with a ni troaniline, such as 3-nitroaniline or 2-fluoro-5-nitroaniline, then make the corresponding isocyanate and convert the isocyanate group to a tetrazolinone ring (as by treatment with trimethylsilylazide) and then reduce the nitro group and substitute an R group on N-4 of the tetrazolinone ring, in either order. Thereafter the amino group may be converted to a N(R ³¹)SO₂R³⁰ group, after which the compound may be halogenated (as with SO₂Cl₂ in dioxane) to place a halogen at the 4-position of the benzene ring (or, when the intermediate being halogenated does not yet have the halogen on its 2-position, this halogenation may place halogen atoms at both the 2- and 4-positions of the benzene ring). Thus the following series of successive intermediates may be prepared from 2-fluoro-5-nitroaniline: 2-fluoro-5-nitrophenyl isocyanate;

1-(2-fluoro-5-nitrophenyl)-1,4-dihydro-5H-tetrazol-5-one (m.p. 124-125°C);

1-(2-fluoro-5-aminophenyl)-1,4-dihydro-5H-tetrazol-5-one (m.p. 169-171°C); or 1-(2-fluoro-5-nitrophenyl)-1,4-dihydro-4-(3-fluoropropyl)-5H-tetrazol-5-one;

1-(2-fluoro-5-aminophenyl)-1,4-dihydro-4-(3-fluoropropyl)-5H-tetrazol-5-one (an oil); 1-[2-fluoro-5-(bis(N-ethylsulfonyl)amino)phenyl]- 1,4-dihydro-4-(3-fluoropropyl)-5H-tetrazol-5-one;

1-[2-fluoro-5-(ethylsulfonylamino)phenyl]-1,4-dihydro-4-(3-fluoropropyl)-5H-tetrazol-5-one.

When the starting material is 3-nitrophenylaniline, the corresponding intermediates without the

2-fluoro substituent may be formed, and the last intermediate may then be treated to place the halogens at its 2- and 4-positions of its benzene ring.

One may also start with, for example 2-fluoroaniline and, by a series of reactions, convert the amino group to a tetrazolinone group ( either through formation of the i socyanate as in Example 1 or through the formation of a tetrazoline thione as discussed below) so as to form the 1-(2-fluorophenyl)-1,4-dihydro-5H-tetrazol-5-one, which (as by substitution of an R group for the H on the N-4 of the tetrazolinone ring) is then converted to, for instance, 1-(2-fluorophenyl)-1,4-dihydro-4-(3-fluorophenyl)-1,4-dihydro-4-(3-fluoropropyl)-5H-tetrazol-5-one. This may be chlorinated to form the compound of Example I Step C, below.

Alternatively, one may start with 4-fluoronitrobenzene and, by a series of reactions (e.g. by reducing the NO₂ group to an amino group and then nitrating to form 3-nitro-4-fluoroaniline, followed by treatment with the alkylsulfonyl halide) to form 2-fluoro-5-bis(N-ethylsulfonylamino)nitrobenzene, which is then reduced to form 2-fluoro-5- bis (N-ethylsulfonyl)amino aniline and then converted to the corresponding 1-[2-fluoro-5- bis (N-ethylsulfonyl)amino-phenyl]-1,4-dihydro-5H-tetrazol-5-one, which may then be treated to substitute an R group on the N-4 of the tetrazolinone ring to form, for instance, the compound of Example II. The conversion of the amino group to the tetrazolinone ring may be effected through formation of the isocyanate in the manner illustrated in Example I (thus forming 2-fluoro-5-(bis (N-ethylsulfonyl)amino)phenyl isocyanate) or through intermediate formation of a tetrazolinethione as discussed below.

From another starting material, 2-fluoro-5-nitroaniline, one may produce (either through the previously mentioned 2-fluoro-5-nitrophenyl isocyanate or through a corresponding tetrazolinethione as discussed below) the previously mentioned 1-( 2-fluoro-5-aminophenyl)-1,4-dihydro-5H-tetrazol-5-one. In another route from the same 2-fluoro-5-nitroaniline starting material, one may (as illustrated in Example VIII) acetylate the NH₂ to protect it; then reduce the nitro group to form an amino group; chlorinate and treat with alkylsulfonyl chloride in any order (to form, e.g., 2-fluoro-4-chloro-5- ( ethylsulfonylamino)-acetanilide); then hydrolyze off the acetyl group to form 2-fluoro-4-chloro-5-(ethylsulfonylamino)aniline, whose free NH₂ group may then be converted (e.g. through formation of an isocyanate or a tetrazolinethione as discussed below) to a tetrazolinone ring, thus forming 1-[2-fluoro-4-chloro-5-(ethylsulfonylamino)phenyl]-1,4-dihydro-5H-tetrazol-5-one. Similarly, starting with 2-fluoro-4-chloro-5- nitroaniline one may acetylate to form 2-fluoro-4-chloro-5-nitroacetanilide (m.p. 138-140°C); reduce to form 2-fluoro-4-chloro-5-aminoacetanilide (m.p. 117-120°C, dec.) and then alkylsulfonate to form, e.g. 2-fluoro-4-chloro-5-bis ( N-ethylsulf onylamino ) acetanilide ( m .p . 218-219°C) and/or 2-fluoro-4-chloro-5-(N-ethylsulfonylamino) acetanilide.

Instead of using the isocyanate route for the production of the aryl tetrazolinone from the corresponding aryl amine (as illustrated in Example 1 Steps A and B), one may react the aryl amine so as to form an aryl tetrazolinethione (with intermediate formation of an aryl isothiocyanate). The aryl tetrazolinethione may then be converted to the corresponding aryl tetrazolinone as by the method illustrated in Example VII below in which the aryl tetrazolinethione is reacted with a base and an alkyl halide to produce an aryl tetrazolyl alkyl sulfide, which is then treated with a base to form the aryl tetrazolinethione. To form the aryl tetrazolinethione from the arylamine one may react the latter with thiophosgene to form the aryl isothiocyanate and then react that isothiocyanate with an azide (e.g. with sodium azide in water at room temperature). Alternatively one may react the aryl amine with carbon disulfide (forming an intermediate dithiocarba- mate) and sodium azide to obtain the aryl tetrazolinethione; during these reactions an intermediate aryl isothiocyanate is formed. By these procedures intermediates such as the following may be produced: sodium N-(2-fluoro-5-nitrophenyl)dithiocarbamate;

2-fluoro-5-nitrophenyl isothiocyanate; 1-(2-fluoro-5-nitrophenyl)-1,4-dihydro-5H-tetrazol-5-thione and its sodium salt; sodium N-(4-chloro-2-fluorophenyl)dithiocarbamate; 4-chloro-2-fluorophenyl isothiocyanate;

1-(4-chloro-2-fluorophenyl)-1,4-dihydro-5H-tetrazol-5-thione and its sodium salt; sodium N-(4-chloro-2-fluoro-5(ethylsulfonylamino) phenyl dithiocarbamate;

2-fluoro-4-chloro-5(ethylsulfonylamino)phenyl isothiocyanate;

1-[2-fluoro-4-chloro-5(ethylsulfonylamino)phenyl]-5H-tetrazol-5-thione and its sodium salt; sodium N-(2-fluoro-5-bis(N-ethylsulfonyl)amino)-phenyl dithiocarbamate;

2-fluoro-5-bis(N-ethylsulfonyl)amino)phenyl isothiocyanate;

1-[2-fluoro-5-(bis(N-ethylsulfonyl)amino)phenyl]-5H-tetrazol-5-thione and its sodium salt.

It will be understood that other salts may be made and used instead of the sodium salts (of, say, the thione or the dithiocarbamate), e.g. salts of other alkali metals or onium salts (e.g. triethylammonium salt).

The reaction with R³⁰SO₂Cl or (R³⁰SO₂)₂O may be effected at, for instance, a temperature below 60°C such as -10 to 50°C in the presence of a suitable base and an inert solvent.

The halogenation reaction with chlorine or bromine may be effected at, for instance, a temperature of about 20 to 150°C.

The introduction of the fluoropropyl group may be effected at, for instance, about 20 to 130°C, preferably by reacting fluoropropyl- X⁶ wherein X⁶ is a leaving group, e.g. 1-bromo-3-fluoropropane, 1-chloro-3-fluoropropane or 3-fluoropropyl methane sulfonate in the presence of a suitable base (e.g. NaOH) and a suitable solvent (e.g. N,N-dimethylformamide or acetone). The Examples below illustrate the preparation of compounds in which Z (in Formula I above) is N(R³¹)SO₂R³⁰. Compounds of this type are listed in Table 1, physical properties thereof are given in Table 2 and herbicidal data therefor are given in Tables 3 and 4.

EXAMPLE I SYNTHESIS OF 1-(5-AMINO-4-CHLORO-2-FLUOROPHENYL)-1,4-DIHYDRO-4-(3-FLUOROPROPYL)-5H- TETRAZOL-5-ONE AS AN INTERMEDIATE

Step A Synthesis of 4-chloro-2-fluorophenyl isocyanate as an intermediate

To a stirred solution of 20.0 g (0.13 mole) of

4-chloro-2-fluoroaniline in 250 ml of toluene was added dropwise a solution of 17.2 ml (0.13 mole) of trichloromethyl chloroformate in 40 ml of toluene. Upon completion of addition the reaction mixture was heated to reflux where it stirred for 16 hours. The solvent was separated from the reaction mixture by distillation to yield 21.8 g of 4-chloro-2-fluorophenyl isocyanate as an oil. The reaction was repeated several times.

Step B Synthesis of 1-(4-chloro-2-fluorophenyl)- 1,4-dihydro-5H-tetrazol-5-one as an intermediate

A stirred solution of 17.1 g (0.10 mole) of 4-chloro-2-fluorophenyl isocyanate and 20.0 g (0.17 mole) of azidotrimethylsilane was heated under reflux for 16 hours. The reaction mixture was cooled to ambient temperature and 60 ml of toluene and 100 ml of water were added. The mixture was allowed to stand for two hours and the resultant solid collected by filtra tion. The filter cake was washed with petroleum ether to yield 14.5 g of 1-(4-chloro-2-fluoro-phenyl-1,4-dihydro-5H-tetrazol-5-one; m.p. 185-187°C. The reaction was repeated several times.

Step C Synthesis of 1-(4-chloro-2-fluorophenyl)- 1,4--dihydro-4-(3-fluoropropyl)-5H-tetrazol- 5-one as an intermediate

A stirred solution of 4.7 g (0.022 mole) of

1-(4-chloro-2-fluorophenyl)-1,4-dihydro-5H-tetrazole, 4.0 g (0.028 mole) of 3-fluoropropyl bromide and 4.0 g (0.028 mole) of potassium carbonate in 60 ml of dimethylformamide was heated at 60°C for 16 hours. The reaction mixture was poured into water and the mixture extracted with diethyl ether. The combined ether extract was dried with magnesium sulfate and filtered. The filtrate was concentrated under reduced pressure to a residue. The residue was dissolved in methylene chloride and passed through a pad of silica gel. The eluate was concentrated under reduced pressure to yield 3.5 g of 1-(4-chloro-2-fluorophenyl)-1,4-dihydro-4- (3-fluoropropyl)-5H-tetrazol-5-one; m.p. 62-63°C. The reaction was repeated several times.

Step D Synthesis of 1-(4-chloro-2-fluoro-5-nitrophenyl)-1,4-dihydro-4-(3-fluoropropyl)-5H- tetrazol-5-one as an intermediate

To a stirred solution of 3.1 g (0.011 mole) of

1-(4-chloro-2-fluorophenyl)-1,4-dihydro-4-(3-fluoropropyl)-5H-tetrazol-5-one in 5 ml of concentrated sulfuric acid was added dropwise 0.9 ml (0.011 mole) of 70% nitric acid. Upon completion of addition the reaction mixture was stirred for two hours at ambient temperature then was poured into ice-water. The mixture was extracted with diethyl ether. The combined extracts were dried with magnesium sulfate and filtered. The filtrate was concentrated under reduced pressure to a residue. The residue was dissolved in methylene chloride and passed through a pad of silica gel. The eluate was concentrated under reduced pressure to yield 2.8 g of 1-(4-chloro-2-fluoro-5-nitrophenyl-1,4-dihydro-4-(3-fluoropropyl)-5H-tetrazol-5-one; m.p. 80-81°C. The reaction was repeated several times.

Step E Synthesis of 1-(5-amino-4-chloro-2-fluorophenyl)-1,4-dihydro-4-(3-fluoropropyl)-5H- tetrazol-5-one as an intermediate

To a 500 ml Parr hydrogenation bottle was added 0.2 g of platinum oxide, 200 ml of ethanol, then 14.0 g (0.014 mole) of 1-(4-chloro-2-fluoro-5-nitrophenyl)-1,4-dihydro-4-(3-fluoropropyl-5H-tetrazol-5-one. The bottle was placed in a Parr hydrogenator and the reaction mixture hydrogenated until the theoretical amount of hydrogen was taken up. The bottle was removed from the hydrogenator and the reaction mixture filtered. The filtrate was concentrated under reduced pressure to a residue. The residue was dissolved in methylene chloride and subjected to column chromatography on silica gel. The appropriate fractions were combined and concentrated under reduced pressure to yield 10.0 g of 1-(5-amino-4-chloro-2-fluorophenyl)-1,4-dihydro-4-(3-fluoropropyl)-5H-tetrazol-5-one; m.p. 84-86°C. The reaction was repeated several times.

EXAMPLE II

SYNTHESIS OF 1-[4-CHLORO-2-FLUORO-5-[BIS(N- ETHYLSULFONYL)AMINO]PHENYL]-1,4-DIHYDRO-4-(3- FLUOROPROPYL)-5H-TETRAZOL-5-ONE To a stirred solution of 1.0 g (0.0035 mole) of 1-(5-amino-4-chloro-2-fluorophenyl)-1,4-dihydro-4-(3-fluoropropyl)-5H-tetrazol-5-one (prepared as in Example I) in 20 ml of methylene chloride was slowly added 0.7 g (0.007 mole) of triethylamine. The reaction mixture was cooled to 10°C and 0.9 g (0.007 mole) of ethanesulfonyl chloride was added dropwise. Upon completion of addition the reaction mixture was allowed to warm to ambient temperature where it stirred for 16 hours. The reaction mixture was poured into ice-water and the organic layer separated. The organic layer was concentrated under reduced pressure to a residue. The residue was dissolved in methylene chloride and subjected to column chromatography on silica gel. The appropriate fractions were combined and concentrated under reduced pressure to yield 0.56 g of 1-[4-chloro-2-fluoro-5-[bis(N-ethylsulfonylamino]phenyl]-1,4-dihydro-4-(3-fluoropropyl)-5H-tetrazol-5-one; m.p. 127-129°C.

The nmr spectrum was consistent with the proposed structure.

EXAMPLE III SYNTHESIS OF 1-[4-CHLORO-2-FLUORO-5-(ETHYLSULFONYLAMINO)PHENYL]-1,4-DIHYDR0-4-(3-FLUOROPROPYL)-5H-TETRAZOL-5-ONE To a stirred solution of 7.9 g (0.017 mole) of 1-[4-chloro-2-fluoro-5-[bis(N-ethylsulfonyl)amino]phenyl]-1,4-dihydro-4-(3-fluoropropyl)-5H-tetrazol-5-one (prepared as in Example II) in 100 ml of ethanol was added dropwise a solution of 1.3 g (0.033 mole) of sodium hdyroxide in 6 ml .of water. Upon completion of addition the reaction mixture stirred for 10 minutes and 100 ml of water was added. The mixture was neutralized with concentrated hydrochloric acid and the resultant solid collected by filtration. The solid was dried to yield 5.0 g of 1-[4-chloro-2-fluoro-5-(ethylsulfonylamino)phenyl]-1,4-dihydro-4-(3-fluoropropyl)-5H-tetrazol-5-one; m.p. 84-85°C.

The nmr spectrum was consistent with the proposed structure.

EXAMPLE IV SYNTHESIS OF 1-[4-BROMO-2-FLUORO-5-[BIS(N- METHYLSULFONYL)AMINO]PHENYL]-1,4-DIHYDRO-4-(3- FLUOROPROPYL) -5H-TETRAZOL-5-ONE This compound was prepared by a method analogous to that of Example II using 1.0 g (0.003 mole) of 1-(5-amino-4-bromo-2-fluorophenyl)1,4-dihydro-4-(3-fluoropropyl)-5H-tetrazol-5-one (prepared as in Example I), 0.69 g (0.006 mole) of methanesulfonyl chloride, and 0.61 g (0.006 mole) of triethylamine in 20 ml of methylene chloride. The yield of 1-[4-bromo-2-fluoro-5-[bis(N-methylsulfonyl)amino]phenyl]1,4-dihydro-4-(3-fluoropropyl)-5H-tetrazol-5-one was 0.6 g; m. p. 143-144°C. The nmr spectrum was consistent with the proposed structure.

EXAMPLE V SYNTHESIS OF 1-[4-CHLORO-2-FLUORO-5-(N-TRIFLUOROMETHYLSULFONYLAMINO)PHENYL]-1,4-DIHYDRO- 4-(3-FLUOROPROPYL)-5H-TETRAZOL-5-ONE POTASSIUM SALT

Step A Synthesis of 1-[4-Chloro-2-fluoro-5-(N- trifluoromethylsulfonylamino)phenyl]- 1,4-dihydro-4-(3-fluoropropyl)-5H-tetrazol- 5-one

To a stirred solution of 1.0 g (0.0034 mole) of 1-(5-amino-4-chloro-2-fluorophenyl)-1,4-dihydro-4-(3-fluoropropyl)-5H-tetrazol-5-one in 30 ml of methylene chloride was added 0.20 g (0.0017 mole) of 4-(N,N- dimethyl)aminopyridine, 0.50 g (0.0017 mole) of trifluoromethylsulfonylanhydride, and an additional 0.20 g (0.0017 mole) of 4-(N,N-dimethyl)aminopyridine. This mixture was stirred at room temperature for 0.5 hour. The resultant solution was extracted with 100 ml of a dilute, aqueous, sodium hydroxide solution. The extract was washed with 50 ml of methylene chloride and was neutralized with concentrated hydrochloric acid. This aqueous solution was extracted several times with ethyl acetate and the extracts were combined. The combined extract was dried over anhydrous sodium sulfate and filtered. The filtrate was evaporated under the reduced pressure to leave a thick oil. This oil was purified by column chromatography on silica gel, eluted with methylene chloride:acetone (95:5) to yield 1.0 g of 1-[4-chloro-2-fluoro-5-(N-trifluoromethylsulfonylamino)phenyl]-1,4-dihydro-4-(3-fluoropropyl-5H-tetrazol-5-one as a solid, m.p. 111-113°C.

The ir and nmr spectra were consistent with the proposed structure.

Step B 1-[4-Chloro-2-fluoro-5-(N-trifluoromethylsulfonylamino)phenyl]-1,4-dihydro-4-(3- fluoropropyl)-5H-tetrazol-5-one potassium salt

A mixture of 0.42 g (0.0010 mole) of 1-[4-chloro-2-fluoro-5-(N-trifluoromethylsulfonylamino)phenyl]-1,4-dihydro-4-(3-fluoropropyl)-5H-tetrazol-5-one and 0.11 g (0.0010 mole) of potassium tert-butoxide in 10 ml of tetrahydrofuran was stirred at room temperature for approximately 30 minutes. The reaction mixture was filtered and the filtrate was evaporated under reduced pressure to yield 0.30 g of 1-]4-chloro-2-fluoro-5-(N-trifluoromethylsulfonylamino)phenyl] 1,4-dihydro-4-(3-fluoropropyl)-5H-tetrazol-5-one potassium salt as a solid, m.p. 158-178ºC.

EXAMPLE VI 1-[4-CHLORO-2-FLUORO-5-[(N-ETHYLSULFONYL-N- PROPYL)-AMINO]PHENYL]-1,4-DIHYDRO-4-(3-FLUOROPROPYL)- 5H-TETRAZOL-5-ONE To a stirred mixture of sodium hydride (0.20 g of a 50% dispersion in mineral oil) in 10 ml of dimethylformamide was added 1.0 g (0.0026 mole) of 1-[4-chloro-2-fluoro-5-(ethylsulfonylamino)phenyl]-1,4-dihydro-4-(3-fluoropropyl)-5H-tetrazol-5-one (prepared as in Example III). The reaction mixture was stirred for 15 minutes and 0.5 g (0.003 mole) of 1-iodopropane was added. This mixture was stirred at room temperature for approximately 18 hours. The mixture was diluted with diethyl ether and washed in succession with an aqueous, 10% sodium hdyroxide solution and an aqueous, saturate dsodium chloride solution. The washed organic phase was dried over anhydrous magnesium sulfate and filtered. The filtrate was evaporated under reduced pressure to leave an oily residue. This residue was purified by column chromatography on silica gel, eluted with ethyl acetate:n-heptane (50:50), to yield 1.0 g of 1-[4-chloro-2-fluoro-5-[(N-ethylsulfonyl-N-propyl)amino]phenyl]-1,4-dihydro-4-(3-fluoropropyl)-5H-tetrazol-5-one as an oil.

The nmr and ir spectra were consistent with the proposed structure.

EXAMPLE VII

1-(4-CHLORO-2-FLUOROPHENYL)-1,4-DIHYDRO-5H- TETRAZOL-5-ONE

Step A Triethylammσnium salt of 4-chloro-2- fluorophenyl dithiocarbamic acid A solution of 30.0 g (0.206 mole) of 4-chloro-2-fluoroaniline and 30 ml (0.215 mole) of triethylamine in 90 ml of carbon disulfide was stirred at room temperature for 22 hours, resulting in a thick suspension. The reaction mixture was filtered. The filter cake was washed with diethyl ether to yield 56.1 g of the triethylammonium salt of 4-chloro-2-fluorophenyl dithiocarbamic acid as a yellow solid.

The nmr spectrum was consistent with the pro- posed structure.

Step B 1-(4-Chloro-2-fluorophenyl)-1,4-dihydro-5H- tetrazol-5-thione

A stirred mixture of 5.0 g (0.016 mole) of the triethylammonium salt of 4-chloro-2-fluorophenyl dithiocarbamic acid, 0.62 g (0.016 mole) of sodium hydroxide, and 4.0 g (0.062 mole) of sodium azide in 10 ml of water was heated at reflux for three hours. The mixture was cooled to room temperature and was acidified with concentrated hydrochloric acid. A precipitate formed and was collected by filtration. The filter cake was washed with water and was dried toyield 3.2 g of 1-(4-chloro-2-fluorophenyl)-1,4-dihydro-5H-tetrazol-5-thione, m.p. 128°C.

The nmr spectrum was consistent with the proposed structure.

Step C [1-(4-Chloro-2-fluorophenyl)-1H-tetrazol- 5-yl]ethyl sulfide

A solution of 1.75 g (0.0076 mole) of 1-(4-chloro-2-fluorophenyl)-1,4-dihydro-5H-tetrazol-5-thione, 0.57 ml (0.0076 mole) of bromoethane, and 1.6 g (0.012 mole) of potassium carbonate in 8 ml of acetone was stirred at room temperature for seven hours. The solvent was evaporated from the reaction mixture under reduced pressure leaving a residue. This residue was dissolved in diethyl ether and the organic solution was washed with water. The washed organic phase was dried over anhydrous magnesium sulfate and filtered. The filtrate was evaporated under reduced pressure to yield 1.6 g of (1-(4-chloro-2-fluorophenyl)-1H-tetrazol-5-yl)ethyl sulfide as a solid, m.p. 76-79°C.

The nmr spectrum was consistent with the proposed structure.

Step D 1-(4-Chloro-2-fluorophenyl)-1,4-dihydro- 5H-tetrazol-5-one

To a stirred solution of 0.12 g (0.0052 mole) of sodium in 16 ml of ethanol was added 1 . 2 g ( 0. 0046 mole) of (1-(4-chloro-2-fluorophenyl)-1H-tetrazol-5-yl) ethyl sulfide. The resultant solution was heated at reflux for six hours. The reaction mixture was cooled and the solvent was evaporated under reduced pressure leaving a residue. This residue was dissolved in 40 ml of water and the aqueous solution was washed with diethyl ether. The aqueous phase was acidified with concentrated hydrochloric acid forming a precipitate. The precipitate was collected by filtration and dried to yield 0.55 g of 1-(4-chloro-2-fluorophenyl)-1,4-dihydro-5H-tetrazol-5-one as a solid, m.p. 194°C.

EXAMPLE VIII

4-CHLORO-5-(N-ETHYLSULFONYLAMINO)-2- FLUOROPHENYLISOTHIOCYANATE

Step A 2-Fluoro-5-Nitroacetanilide

To a stirred solution of 18.0 g (0.11 mole) of 2-fluoro-5-nitroaniline in 100 ml of dioxane was added 15.3 g (0.15 mole) of acetic anhydride. The reaction mixture was heated at reflux for two hours. The solvent was removed from the mixture by distillation under reduced pressure leaving a solid residue. This residue was stirred in 25 ml of methylene chloride and filtered. The filter cake was dried to yield 20.5 g of 2-fluoro-5-nitroacetanilide, m.p. 177-178°C.

Step B 5-Amino-2-fluoroacetanilide

Hydrogenation of 20.0 g (0.10 mole) of 2-fluoro-5-nitroacetanilide with a catalytic amount (0.3 g) of platinum oxide in 200 ml of an ethanol/ethylacetate (80/20) solution yielded 16.0 g of 5-amino-2-fluoroacetanilide as a solid.

Step C 2-Fluoro--bis(N-ethylsulfonylamino)- acetanilide

To a stirred mixture of 15.4 g (0.091 mole) of 5-amino-2-fluoroacetanilide in 75 ml of methylene chloride was added 18.5 g (0.183 mole) of triethyl amine. To this mixture was added slowly 23.5 g (0.183 mole) of ethyl sulfonyl chloride. The resultant mixture was stirred at room temperature for approximately 18 hours. The reaction mixture was passed through a column of silica gel, eluting with methylene chloride, to yield 12.0 g of 2-fluoro-5-bis (N-ethylsulfonylamino)acetanilide.

Steps A-C were repeated to prepare additional 2-fluoro-5-bis(N-ethylsulfonylamino)acetanilide.

Step D 2-Fluoro-5-(N-ethylsulfonylamino)acetanilide To a stirred solution of 27.0 g (0.077 mole) of 2-fluoro-5-bis (N-ethylsulfonylamino) acetanilide in 100 ml of dioxane was added a solution of sodium hydroxide (5.65 g, (0.0141 mole) in 20 ml of water. Approximately 100 ml of water was added and the resultant solution was stirred at room temperature for about 15 minutes. The dioxane solvent was removed from the solution by extraction with diethyl ether. The remaining aqueous phase was acidified with concentrated hydrochloric acid forming a precipitate. The precipitate was collected by filtration and dried to yield 14.8 g of 2-fluoro-5-(N-ethylsulfonylamino)acetanilide, m.p. 175.5-177°C. Additional product (1.9 g) was collected by extracting the filtrate with ethyl acetate and evaporating the extract after drying over anhydrous magnesium sulfate.

The nmr and ir spectra were consistent with the proposed structure.

Step E 4-Chloro-2-fluoro-5-(N-ethylsulfonylamino) acetanilide

To a stirred solution of 8.0 g (0.031 mole) of 2-fluoro-5-(N-ethylsulfonylamino)acetanilide in 200 ml of dioxane was added slowly 2.5 ml (0.031 mole) of thionyl chloride. This mixture was heated at 80 °C for two days. The mixture was poured into ice water and the mixture was extracted with ethyl acetate. The extract was dried over anhydrous magnesium sulfate and filtered. The filtrate was evaporated under reduced pressure to yield 8.1 g of 4-chloro-2-fluoro-5-(N-ethylsulfonylamino) acetanilide.

Step F 4-Chloro-2-fluoro-5-(N-ethylsulfonylamino)aniline A stirred mixture of 2.0 g (0.0068 mole) of 4-chloro-2-fluoro-5-(N-ethylsulfonylamino) acetanilide and 0.84 g (0.020 mole) of sodium hydroxide in 100 ml of water was heated at reflux for approximately 18 hours. The reaction mixture was cooled and neutralized with concentrated hydrochloric acid. The neutralized mixture was extracted with ethylacetate. The extract was washed with an aqueous, saturated sodium chloride solution. The washed extract was dried over anhydrous magnesium sulfated and filtered. The filtrate was evaporated under reduced pressure to yield 2.7 g of 4-chloro-2-fluoro-5-(N-ethylsulfonylamino)aniline as a solid.

The nmr was consistent with the proposed structure.

Step G 4-Chloro-5-(N-ethylsulfonylamino)-2- fluorophenylisothiocyanate

Under a dry nitrogen atmosphere 0.84 ml (0.011 mole) of thiophosgene was added to a stirred solution of 2.8 g (0./011 mole) of 4-chloro-2-fluoro-5-(N-ethylsulfonylamino)aniline in 250 ml of chloroform. To this mixture was added dropwise 1.6 g (0.012 mole) of triethylamine. The resultant mixture was stirred at room temperature for approximately 18 hours. The solvent was removed from the mixture by evaporation under reduced pressure leaving an oily residue. This residue was purified by column chromatography on silica gel, electing with methylene chloride/hexane (60/40) followed by methylenechloride, to yield 1.6 g of 4-chloro-5-(N-ethylsulfonylamino)-2-fluorophenylisothiocyanate as a solid, m.p. 104-105°C.

The nmr and ir spectra were consistent with the proposed structure. The herbicidal data in the following Tables 3 and 4 was obtained in the manner described in PCT published application no. WO 85/01939, previously mentioned, usually employing solutions of the herbicidal compound in 50/50 acetone/water mixtures. In those tables, the test compounds are identified by numbers which correspond to those in Table 1, "kg/ha" is kilograms per hectare, and "% C" is percent control. In addition, tests of the effectiveness of weed control of paddy rice were done in pots containing clay loam paddy soil under water maintained at a depth of 3 cm. In one test tubers of narrowleaf arrowhead (Sagittaria pymaea) and rhizomes of flatsedge (Cyperus serotinus) were planted in pots at depth of 2 cm and 0.5 cm respectively, rice seedlings of 2.2 leaf state were transplanted in depth of 2 cm and 0 cm and a controlled amount of a 10% wp (wettable powder) formulation of the herbicidal compound in water was dropped into the water over the soil at 1 day and 11 days, respectively, after transplanting. In another test, seeds of various weed species (including barnyardgrass, Echinochoa crus-galli ; small flower umbrellaplant , Cyperus difformis; bulrush, Scripus juncoides; Japanese ducksalad, Monochoria vaginalis; annual broadleaf weeds; and narrowleaf waterplantain, Alisma canal iculatium ) were sown on the surface of the soil and the same (1 day and 11 day) herbicide applications were made. In tests of compound 4 (of Table 1 below) very high activity against weeds of wide spectrum were shown for both the 1 day and 11 day treatments at rates of e.g., about .06 kg/ha or less, while there was selectivity favorable to rice transplanted at a depth of 2 cm.

Herbicidal data at selected application rates are given for various compounds of the invention in the tables below. The test compounds are identified in the tables of herbicidal data below by numbers which correspond to those used above in those tables. "kg/ha" is kilograms per hectare. For herbicidal application, the active compounds are formulated into herbicidal compositions by admixture in herbicidally effective amounts with adjuvants and carriers normally employed in the art for facilitating the dispersion of active ingredients for the particular utility desired, recognizing the fact that the formulation and mode of application of a toxicant may affect the activity of the material in a given application. Thus, for agricultural use the present herbicidal compounds may be formulated as granules of relatively large particle size, as water-soluble or water-dispersible granules, as powdery dusts, as wettable powders, as emulsifiable concentrates, as solutions, or as any of several other known types of formulations, depending on the desired mode of application.

These herbicidal compositions may be applied either as water-diluted sprays, or dusts, or granules (e.g. for paddy rice) in the areas in which suppression of vegetation is desired. These formulations may contain as little as 0.1%, 0.2% or 0.5% to as much as 95% or more by weight of active ingredient.

Dusts are free flowing admixtures of the active ingredient with finely divided solids such as talc, natural clays, kieselguhr, flours such as walnut shell and cottonseed flours, and other organic and inorganic solids which act as dispersants and carriers for the toxicant; these finely divided solids have an average particle size of less than about 50 microns. A typical dust formulation useful herein is one containing 1.0 part or less of the herbicidal compound and 99.0 parts of talc. Wettable powders, also useful formulations for both pre- and postemergence herbicides, are in the form of finely divided particles which disperse readily in water or other dispersant. The wettable powder is ultimately applied to the soil either as a dry dust or as an emulsion in water or other liquid. Typical carriers for wettable powders include Fuller's earth, kaolin clays, silicas, and other highly absorbent, readily wet inorganic diluents. Wettable powders normally are prepared to contain about 5-80% of active ingredient, depending on the absorbency of the carrier, and usually also contain a small amount of a wetting, dispersing or emulsifying agent to facilitate dispersion. For example, a useful wettable powder formula- tion contains 80.8 parts of the herbicidal compound, 17.9 parts of Palmetto clay, and 1.0 part of sodium lignosulfonate and 0.3 part of sulfonated aliphatic polyester as wetting agents. Other wettable power formulations are: Component: % by Wt.

Active ingredient 40.00

Sodium ligninsulfonate 20.00

Attapulgite clay 40.00

Total 100. 00

Active ingredient 90 . 00 Dioctyl sodium sulfosuccinate 0 . 10 Synthetic fine silica 9 . 90 Total 100 . 00

Active ingredient 20 .00

Sodium alkylnaphthalenesulfonate 4 . 00

Sodium ligninsulfonate 4 . 00

Low viscosity methyl cellulose 3 . 00

Attapulgite clay 69 . 00

Total 100.00 Component: % by Wt .

Active ingredient 25.00

Base: 75.00

96% hydrated aluminum magnesium silicate 2% powdered sodium lignosulfonate

2% powdered anionic sodium alkylnaphthalenesulfonate

Total 100.00

Frequently, additional wetting agent and/or oil will be added to the tank-mix for postemergence application to facilitate dispersion on the foliage and absorption by the plant.

Other useful formulations for herbicidal applications are emulsifiable concentrates (ECs) which are homogeneous liquid or paste compositions dispersible in water or other dispersant, and may consist entirely of the herbicidal compound and a liquid or solid emulsifying agent, or may also contain a liquid carrier, such as xylene, heavy aromatic naphthas, isophorone, or other non-volatile organic solvent. For herbicidal application these concentrates are dispersed in water or other liquid carrier, and normally applied as a spray to the area to be treated. The percentage by weight of the essential active ingredient may vary according to the manner in which the composition is to be applied, but in general comprises 0.5 to 95% of active ingredient by weight of the herbicidal composition. The following are specific examples of emulsifiable concentrate formulations: Component: % by Wt

Active ingredient 53.01 Blend of alkylnaphthalenesulfonate and polyoxyethylene ethers 6.00 Epoxidized soybean oil 1.00

Xylene 39.99

Total 100.00

Active ingredient 10.00 Blend of alkylnaphthalenesulfonate and polyoxyethylene ethers 4.00

Xylene 86.00

Total 100.00

Flowable formulations are similar to ECs except that the active ingredient is suspended in a liquid carrier, generally water. Flowables, like ECs, may include a small amount of a surfactant, and contain active ingredient in the range of 0.5 to 95%, frequently from 10 to 50%, by weight of the composition. For application, flowables may be diluted in water or other liquid vehicle, and are normally applied as a spray to the area to be treated.

The following are specific examples of flowable formulations:

Component: % by Wt.

Active ingredient 46.00

Colloidal magnesium aluminum silicate 0.40

Sodium alkylnaphthalenesulfonate 2.00 Paraformaldehyde 0.10

Water 41.42

Propylene glycol 7.50

Acetylenic alcohols 2.50

Xanthan gum 0.80 Total 100.00 Component: % by Wt.

Active ingredient 45.00

Water 48.50

Purified smectite clay 2.00 Xanthan gum 0.50

Sodium alkylnaphthalenesulfonate 1.00

Acetylenic alcohols 3.00

Total 100.00

Typical wetting, dispersing or emulsifying agents used in agricultural formulations include, but are not limited to, the alkyl and alkylaryl sulfonates and sulfates and their sodium salts; alkylaryl polyether alcohols; sulfated higher alcohols; polyethylene oxides; sulfonated animal and vegetable oils; sulfonated petroleum oils; fatty acids esters of polyhydric alcohols and the ethylene oxide addition products of such esters; and the addition product of long-chain mercaptans and ethylene oxide. Many other types of useful surface-active agents are available in commerce. The surface-active agent, when used, normally comprises from 1 to 15% by weight of the composition.

Other useful formulations include simple solutions or suspensions of the active ingredient in a relatively non-volatile solvent such as water, corn oil, kerosene, propylene glycol, or other suitable solvents. The following illustrate specific suspensions:

Oil Suspension: % by Wt.

Active ingredient 25.00 polyoxyethylene sorbitol hexaoleate 5.00

Highly aliphatic hydrocarbon oil 70.00

Total 100.00 Aqueous Suspension:

Active ingredient 40.00

Polyacrylic acid thickener 0.30

Dodecylphenol polyethylene glycol ether 0.50 Disodium phosphate 1.00

Monosodium phosphate 0.50

Polyvinyl alcohol 1.00

Water 56.70

Total 100.00

Other useful formulations for herbicidal applications include simple solutions of the active ingredient in a solvent in which it is completely soluble at the desired concentration, such as acetone, alkylated naphthalenes, xylene, or other organic solvents.

Granular formulations, wherein the toxicant is carried on relatively coarse particles, are of particular utility .for aerial distribution or for penetration of cover crop canopy. Pressurized sprays, typically aerosols wherein the active ingredient is dispersed in finely divided form as a result of vaporization of a low boiling dispersant solvent carrier, such as the Freons, may also be used. Water-soluble or water-dispersible granules are also useful formulations for herbicidal application of the present compounds. Such granular formulations are free-flowing, non-dusty, and readily water-soluble or water-miscible. The soluble or dispersible granular formulations described in U.S. patent No. 3,920,442 are useful herein with the present herbicidal compounds. In use by the farmer on the field, the granular formulations, emulsifiable concentrates, flowable concentrates, solutions, etc., may be diluted with water to give a concentration of active ingredient in the range of say 0.1% or 0.2% to 1.5% or 2%. The active herbicidal compounds of this invention may be formulated and/or applied with insecticides, fungicides, nematicides, plant growth regulators, fertilizers, or other agricultural chemicals and may be used as effective soil sterilants as well as selective herbicides in agriculture. In applying an active compound of this invention, whether formulated alone or with other agricultural chemicals, an effective amount and concentration of the active compound is of course employed; the amount may be as low as, for example, 7 g/ha or lower.

The active herbicidal compounds of this invention may be used in combination with other herbicides, e.g. they may be mixed with, say, an equal or larger amount of a known herbicide such as chloroacetanilide herbi- cides such as 2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl)acetamide (alachlor), 2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide (metolachlor), and N-chloroacetyl-N-(2,6-diethylphenyl)glycine (diethatyl-ethyl); benzothiadiazinone herbicides such as 3-(1-methylethyl)-(1H)-2,1,3-benzothiadiazin-4-(3H)-one-2,2-dioxide (bentazon); triazine herbicides such as 6-chloro-N-ethyl-N-(1-methylethyl)-1,3,5-triazine-2,4-diamine (atrazine), and 2- [4-chloro-6-(ethylamino)-1,3,5-triazin-2-yl]amino -2-methylpropanenitrile (cyanazine); dinitrolaniline herbicides such as 2,6-dinitro-N,N-dipropyl-4-(trifluoromethyl)benzeneamine (trifluralin); and aryl urea herbicides such as N'-(3,4-dichlorophenyl)-N,N-dimethylurea (diuron) and N,N-dimethyl-N'-[3-(trifluoromethyl)phenyl]urea (fluometuron); and 2-[(2-chlorophenyl)methyl]-4,4-dimethyl-3-isoxazolidone.

It is apparent that various modifications may be made in the formulation and application of the compounds of this invention without departing from the inventive concepts herein as defined in the claims.

The compounds in which Z is ethylsulfonylamino, such as compounds 4, 31, 34, have been found to be particularly useful when used pre-emergently against broad leaf weeds with crops such as corn, rice, wheat and soybeans. Ihe presence of an N-methylsulfonyl N-ethylsulfonylamino group, as in compound 11, gives particularly good results in postemergence use against broadleafed weeds with a favorable selectivity for corn, wheat and soybeans.

Other representative compounds are those which are identical with compounds 5, 11-17, 28-32, 35, 40-51, 54 to 67 respectively except that X¹ is F and X² is Br. Other representative compounds are those which are identical with compounds 1-67 respectively except that X¹ is F and X² is CF₃. Still other representative compounds are those which are identical with compounds 1-67 respectively except that X¹ is Br.

Compound 4 also shows very good control of broadleaf weeds in plantings of such crops as corn, wheat, barley, oats, rice and sorghum when applied post-emergently. Here rates of application in the field may be, for instance, in the range of about 30 to 250 g/ha, e.g., 125 g/ha.

1342W30132Wmd

Table 3

Preemergence Herbicidal Activity (% Control)

Compound No. 2 4 6 8 9 10

Rate (kg/ha) 0.25 0.25 8.0 0.5 1.0 1.0

Species

Cotton 95 95 70 95 100 100

Soybean 20 0 30 30 50 80

Field Corn 40 30 20 40 100 95

Rice 70 40 70 95

Wheat 10 10 0 10 90 90

Field Bindweed 100 100 20 40 100

Morningglory 100 100 60 60 100 100

Velvetleaf 100 100 95 100 100 100

Barnyardgrass 60 80 30 40 100 100

Green Foxtail 40 20 30 50 100 100

Johnsongrass 40 30 20 50 80 95

Compound No. 11 12 13 14 15 16

Rate (kg/ha) 0.5 0.5 1.0 1.0 0.5 0.5

Species

Cotton 100 100 95 100 100 100

Soybean 30 80 95 95 95 80

Field Corn 95 100 100 100 100 95

Rice 80 90 100 100 100 70

Wheat 80 100 100 100 100 60

Field Bindweed 100 100 100 100 100 100

Morningglory 100 100 95 100 100 100

Velvetleaf 100 100 100 100 100 100

Barnyardgrass 100 100 100 100 100 90

Green Foxtail 100 100 100 100 100 100

Johnsongrass 90 100. 100 100 100 90

Compound No. 17 18 20 21 22 23

Rate (kg/ha) 1.0 8.0 0.5 0.5 1.0 8.0

Species

Cotton 10 100 90 95 100 30

Soybean 10 10 20 20 60 10

Field Corn 10 0 90 90 95 90

Rice 10 70 80 80 20

Wheat 20 0 30 95 90 40

Field Bindweed 10 30 20 100 70

Morningglory 30 40 70 95 100 70

Velvetleaf 90 95 100 100 100 100

Barnyardgrass 20 20 90 100 100 80

Green Foxtail 30 10 95 100 100 95

Johnsongrass 60 40 90 100 100 50 Table 3

Continued

Compound No . 25 26 27 28 29 30

Rate (kg/ha) 0.5 0.500 1.0 0.5 0.25 0.25

Species

Cotton 10 50 95 100 60 50

Soybean 20 0 30 0 30 10

Field Corn 80 90 95 30 95 10

Rice 20 20 60 70 60 20

Wheat 20 60 60 30 80 0

Field Bindweed 0 100 100 70 95

Morningglory 10 60 100 100 70 60

Velvetleaf 20 100 100 100 100 100

Barnyardgrass 50 100 100 95 100 0

Green Foxtail 10 60 100 90 100 10

Johnsongrass 60 95 95 70 100 60

Compound No. 31 32 33 34 35 36

Rate (kg/ha) 0.25 2.0 0.25 0.25 4.0 2.0

Species

Cotton 100 100 100 95 100 70

Soybean 10 40 10 20 80 0

Field Corn 30 50 40 60 50 70

Rice 40 95 80 60 95 0

Wheat 20 10 20 0 70 0

Field Bindweed 100 100 100 100 100 100

Morningglory 100 100 100 100 100 90

Velvetleaf 100 100 100 100 100 95

Barnyardgrass 95 95 95 95 90 70

Green Foxtail 50 60 70 70 100 50

Johnsongrass 70 80 70 50 95 40

Compound No. 37 38 39 40 41 49 51

Rate (kg/ha) 2.0 1.0 1.0 4.0 2.0 2.0 2.0

Species

Cotton 10 70 50 50 95 90 100

Soybean 0 50 10 20 50 20 20

Field Corn 20 10 70 30 40 90 70

Rice 0 40 10 20 10 70. 30

Wheat 30 10 20 30 10 95 20

Field Bindweed 20 95 70 40 100 80 100

Morningglory 20 100 100 70 100 70 100

Velvetleaf 100 100 100 100 100 100 100

Barnyardgrass 80 80 60 70 80 100 70

Green Foxtail 50 80 50 40 95 100 95

Johnsongrass 70 40 10 40 20 80 10 Table 4

Postemergence Herbicidal Activity (% Control)

Compound No. 2 4 6 8 9 10

Rate (kg/ha) 0.25 0.25 8.0 0.5 1.0 1.0

Species

Cotton 100 100 90 95 100 100

Soybean 50 60 50 40 30 95

Field Corn 80 50 40 50 30 90

Rice 50 20 30 20 30

Wheat 20 20 20 30 80 60

Field Bindweed 100 100 70 30 100

Morningglory 100 95 100 40 100 100

Velvetleaf 100 100 100 95 100 100

Barnyardgrass 40 50 50 40 100 100

Green Foxtail 50 80 50 50 60 100

Johnsongrass 50 20 20 30 70 100

Compound No. 11 12 13 14 15 16

Rate (kg/ha) 0.5 0.5 1.0 1.0 0.5 0.5

Species

Cotton 100 100 100 100 100 100

Soybean 60 70 95 100 95 70

Field Corn 80 70 100 100 95 50

Rice 40 30 100 100 60 50

Wheat 70 80 100 100 100 60

Field Bindweed 100 100 100 100 80 100

Morningglory 80 100 100 100 100 100

Velvetleaf 100 100 100 100 100 100

Barnyardgrass 80 70 100 100 80 50

Green Foxtail 80 70 100 100 90 70

Johnsongrass 50 70 100 100 80 60

Compound No. 17 18 20 22 23 25

Rate (kg/ha) 1.0 8.0 0.5 1.0 8.0 0.5

Species

Cotton 90 60 90 100 60 40

Soybean 50 60 30 95 40 20

Field Corn 60 30 20 100 30 60

Rice 20 20 80 20

Wheat 40 10 50 90 20 20

Field Bindweed 80 50 30 95 50 40

Morningglory 60 70 90 95 60 30

Velvetleaf 95 95 100 100 100 80

Barnyardgrass 40 30 30 100 40 20

Green Foxtail 40 30 40 100 40 30

Johnsongrass 40 30 30 100 40 20 Table 4

Continued

Compound No. 26 27 28 29 30 31

Rate (kg/ha) 0.5 1.0 0.5 0.25 0.25 0.25

Species

Cotton 100 100 100 70 90 100

Soybean 50 90 30 70 40 80

Field Corn 100 95 40 40 30 30

Rice 40 30 70 60 10 40

Wheat 90 80 60 80 10 40

Field Bindweed 95 100 80 70 100

Morningglory 100 100 100 70 80 100

Velvetleaf 100 100 100 100 100 100

Barnyardgrass 80 100 100 50 10 80

Green Foxtail 80 100 100 60 0 60

Johnsongrass 70 100 95 70 0 60

Compound No. 32 33 34 35 36 37

Rate (kg/ha) 2.0 0.25 0.25 4.0 2.0 2.0

Species

Cotton 100 100 100 100 70 70

Soybean 100 70 70 100 10 40

Field Corn 70 30 40 70 10 20

Rice 40 80 70 80 10 20

Wheat 40 40 40 40 10 20

Field Bindweed 100 100 100 95 60 40

Morningglory 100 100 100 100 80 50

Velvetleaf 100 100 100 100 90 80

Barnyardgrass 70 80 70 70 50 30

Green Foxtail 40 100 90 100 50 50

Johnsongrass 70 70 50 90 50 20

Compound No. 38 39 40 43 49 51

Rate (kg/ha) 1.0 1.0 4.0 2.0 2.0 2.0

Species

Cotton 95 100 40 100 100 100

Soybean 90 95 20 50 50 70

Field Corn 50 50 20 30 80 60

Rice 20 20 10 50 50 60

Wheat 50 30 20 50 80 70

Field Bindweed 100 100 40 100 80 100

Morningglory 100 100 60 100 90 100

Velvetleaf 100 100 70 95 100 100

Barnyardgrass 50 50 60 50 95 80

Green Foxtail 80 50 30 40 95 80

Johnsongrass 80 50 30 70 90 70

Claims

Claims:

Compound of the formula

or a salt thereof, wherein X¹ is F or Cl and X² is

Cl or Br.

Compound as in claim 1 in which X¹ is F and X² is Cl.

Compound of the formula

wherein X¹ is F or Cl and X² is Cl or Br.

A compound as in claim 3 in which X¹ is

F and X² is Cl.

A compound of the formula

where Q³ is NO₂, NH₂, -NCS, -NCO, or

; X⁴ is Br or Cl, R³⁰ is alkyl, haloalkyl or aryl and R³¹ is hydrogen, a salt-forming group, alkyl, benzyl, haloalkyl, alkoxy, SO₂R³⁰, alkynyl, alkenyl, -alkylene SO₂R ³⁰, alkoxymethyl, cyanomethyl, carboxymethyl or alkoxycarbonylmethyl, or

R³⁰ and R³¹ together are an alkylene radical.

6. A compound of the formula

where Q⁴ is NO₂ , NH ₂ , NCS , NCO, NH-C ( S ) SM,

M is an alkali metal or onium ion, M' is H or M, R³⁰ is alkyl, haloalkyl or aryl, and R³¹ is hydrogen, a salt-forming group, alkyl, benzyl, haloalkyl, alkoxy,

SO₂R ³⁰ alkynyl, alkenyl, -alkylene SO₂R ³⁰, alkoxymethyl, cyanomethyl, carboxymethyl or alkoxycarbonylmethyl, or R³⁰ and R³¹ together are an alkylene radical.

7. A compound of the formula

and M ' is H or alkali metal or onium ion. A compound of the formula

where Q⁶ is or

and M' is H or alkali metal or onium ion. 9. A compound of the formula

where Q⁷ is -NCS, -NH-C(S)SM or

M is alkali metal or onium ion and M' is H or M. 10. A compound of the formula

where Q⁸ is

or

11. Process which comprises treating a compound of the formula

to convert it to a compound of the formula

in which X² is Cl or Br, X^2' is H or the same as X²,

R^a is H or -CH₂CH₂CH₂F, Z¹ is NHSO₂C₂H₅, or H or nitro or amino, said process comprising a sequence of steps which includes the following in any order: alkylsulfonating to introduce the C₂H₅SO₂ group when Z¹ is not C₂H₅SO₂NH- halogenating to introduce the X group when

X^2' is not X² and haloalkylating to introduce the CH₂CH₂CH₂F group when R^a is not CH₂CH₂CH₂F.

12. An herbicidal composition comprising an herbicidally effective amount of the compound of claim 1 in admixture with a suitable carrier.

13. A composition as in claim 12 comprising an additional herbicide.

14. A composition as in claim 13 in which said additional herbicide is 2-(2-chlorophenyl)methyl-4,4-dimethyl-3-isoxazolidinone.

15. A composition as in claim 13 in which said additional herbicide is a grass-controlling herbicide having a selectivity favorable to soybeans.

16. Composition as in claim 12 in which X¹ is F and X ² is Cl.

17. An herbicidal composition comprising an herbicidally effective amount of the compound of claim 3

18. A method for controlling undesired plant growth which comprises applying to the locus where control is desired an herbicidally effective amount of the composition of claim 12.

19. A method as in claim 18 including the steps of planting said locus with soybeans and applying said composition pre-emergently to said locus.

20. A method as in claim 19 including the step of applying post-emergently to said locus a grass-controlling herbicide which has a selectivity favorable to soybeans. 21. A method for controlling undesired plant growth which comprises applying to the locus where control is desired an herbicidally effective amount of the composition of claim 17.

22. A method as in claim 21 including the steps of planting said locus with cotton and applying said composition pre-emergently to said locus.