AU566839B2

AU566839B2 - Herbicidal 1-aryl-2-1, 2, 4-triazolin-5-ones

Info

Publication number: AU566839B2
Application number: AU41154/85A
Authority: AU
Inventors: L.L. Maravetz
Original assignee: FMC Corp
Current assignee: FMC Corp
Priority date: 1984-03-29
Filing date: 1985-03-04
Publication date: 1987-10-29
Anticipated expiration: 2005-03-04
Also published as: CA1246589A; BR8506209A; HUT38220A; IT8520115A0; WO1985004307A1; EP0177553A1; IT1200433B; AU4115485A; IL74737A0; HU194703B; EP0177553A4

Description

HERBICIDAL 1-ARYI-Δ²-1,2,4-TRIAZOLIN-5-ONES

The invention described in this application pertains to weed control in agriculture, horticulture, or other fields where there is a desire to control unwanted plant growth. More specifically, the present application describes novel herbicidal 1-aryl-Δ²- 1,2,4-triazolin-5-ones, herbicidal compositions containing the new compounds, methods for preparing the compounds, and methods for preventing or destroying undesired plant growth by preemergence or post-emergence application of the herbicidal compositions to the locus where control is desired. The present compounds may be used to effectively control a variety of both grassy and broadleaf plant species. The present invention is particularly useful in agriculture, as the novel aryltriazolinones described herein show a selectivity favorable to cotton or other crops at application levels which inhibit the growth of or destroy a variety of weeds. Various herbicidal 1-aryl-Δ²-1,2,4-triazolin-5-ones are known in the art. U.S. Patent No. 4,318,731 and corresponding British Patent No. 2,056,971 disclose herbicidal aryltriazolinones of the formula

wherein R ¹ is alkyl, R² is hydrogen, alkyl, or alkenyl, and X is hydroxy, alkyl, alkoxy, alkoxy- alkoxy, alkenyloxy, or alkyloxycarbonylalkyloxy. British Patent No. 2,090,250, a continuation-in-part of the above British patent, adds to the above genus compounds wherein R² is alkynyl, halomethyl, or haloethyl, and X is alkoxy, alkenyloxy, alkynyloxy, alkoxyalkoxy, hydroxy, halomethyloxy, or haloethyloxy.

European Patent Application Publication No. 55,105 discloses a series of herbicidal aryltriazolinones of the formula

wherein R is alkyl, alkenyl, or cycloalkyl, X is chlorine or bromine, and Y is hydrogen or alkoxy. Japanese Kokai 81-32,468 discloses herbicidal aryltriazolinones of the formula

wherein R is hydrogen, alkyl, or 2-propenyl, and R¹ is methyl or alkoxy.

South African Patent Application No. 78/3182 discloses herbicidal aryltriazolinones of the formula

wherein R_n is hydrogen or represents 1 to 4 same or different radicals selected from halogen, nitro, cyano, optionally halo substituted alkyl, alkoxy, or alkylthio, and optionally substituted phenyl or phenoxy, and R¹ is alkyl, alkoxyalkyl, dialkoxyethyl, dialkylaminoethyl, or cycloalkyl.

U.S. Patent No. 4,315,767 discloses herbicidal bicyclic compounds of the following formula

wherein V is hydrogen, halogen, methyl, or alkoxy, X is hydrogen, halogen, cyano, methyl, methoxy, or nitro, Y is hydrogen, halogen, or methyl, m and n are 0 to 4 (m plus n is 2 to 4), Q is oxygen or sulfur, and Z is oxygen, S(O)_p, or NR¹ wherein p is 0-2 and R ¹ is alkyl, provided that when m plus n is 2 or

4 then Y and X are other than hydrogen, and when Z is

S(O)_p then n is 1 to 4. Additional herbicidal bicyclic compounds based on the aryltriazolinone nucleus are disclosed in U.S.

Patent No. 4,213,773 and have the following structural formula

wherein V is hydrogen, halogen, hydroxy, alkyl, or -OR¹; R¹ is optionally substituted alkyl, cycloalkyl, cycloalkylalkyl, optionally substituted alkenyl, alkynyl, optionally substituted benzyl, alkylaminocarbonyl, (alkyl) (methyl or methoxy)aminocarbonyl, acyl, alkoxycarbonyl, or -CHR ⁷R⁸ wherein

R ⁷ is hydrogen or alkyl and R⁸ is cyano, acetyl, hydroxycarbonyl, alkoxycarbonyl, hydroxymethyl, alkoxymethyl, alkylcarbonyloxyrmethyl, hydroxycarbonylethenyl, alkoxycarbonylethenyl, or a group

-CO-NR¹¹R¹² wherein R¹¹ is hydrogen, alkyl, alkenyl, or alkoxy, and R ¹² is hydrogen or alkyl; X is halogen, cyano, methyl, methoxy, or nitro; Y is hydrogen, halogen, or methyl; Z is hydrogen or halogen; n is 3-5; m is 0-2; and Q is oxygen or sulfur, with certain provisos. A class of Δ²-1,2,4-triazolin-5-ones is disclosed as fungicides in U.S. 4,098,896. The disclosed genus has the formula

wherein R is alkyl, alkenyl, alkynyl, cycloalkyl, or optionally substituted phenyl or arylalkyl, R¹ is haloalkyl or haloalkenyl, and R² is optionally substituted alkyl, alkenyl, or alkynyl, or optionally substituted aryl, arylalkyl, or alkylaryl. The compounds of this invention are 1-[4-chloro- 2-fluoro-5-(substituted)oxyphenyl]-3-methy1-4-difluoromethyl-Δ²-1,2,4-triazolin-5-ones of the formula

wherein R is alkyl, alkenyl, alkynyl, alkpxyalkyl, or alkyl S(O)_n-alkyl wherein n is 0 to 2. The present compounds are named in accordance with the numbering system shown in formula I, for the ring atoms of the heterocycle which is the same as the numbering system used in U.S. 4,318,731, supra, for similar compounds.

A preferred embodiment of this invention is 1-(4- chloro-2-fluoro-5-propargyloxyphenyl)-3-methyl-4- difluoromethyl-Δ²-1,2,4-triazolin-5-one, the compound of the formula

Other preferred embodiments include the compounds of formula I in which R is -CH(CH₃)₂, -CH(CH₃)C≡CH, -CH₂OCH₃, -CH₂CH=CH₂, and -CH(CH₃)CH₂OCH₃.

The present compounds, which have a fluorine atom at the C-2 position of the phenyl ring, in general have herbicidal properties far superior to those of the corresponding compounds having a chlorine atom at C-2 of the phenyl ring, and are highly active at low application rates against a variety of grassy and broadleaf weed species in both preemergence and postemergence applications.

The compounds of this invention may be prepared by methods analogous to the methods described in the references above for similar compounds or by methods within the skill of the art. The disclosures in the above references pertaining to methods of preparation are incorporated herein by reference. A method of preparation exemplified herein is illustrated in the following chemical equations for the compound of formula I(a).

Optionally, the propargyloxy group, also known as 2-propynyloxy, may be added at an earlier stage in the synthesis rather than in the last step: for example, at the outset by using 4-chloro-2-fluoro-5-propargyloxyaniline as the starting material in place of compound II (the corresponding 5-methoxy compound). 4-Chloro-2-fluoro-5-methoxyaniline, compound II, was prepared in five steps from commercially available 2-chloro-4-fluorophenol in a known manner (see E. Nagano et al. in European Patent Application

Publication No. 69,855, published January 19, 1983). Compound II was converted to the corresponding hydrazine III by diazotization followed by reduction of the diazonium salt with stannous chloride. Treatment of the arylhydrazine with pyruvic acid in the presence of 10% hydrochloric acid and ethanol gave the arylhydrazone IV which upon treatment with diphenylphosphoryl azide afforded the aryltriazolinone V. Compound V was converted to the present compound I(a) in three steps by methods analogous to those disclosed in British Patent No. 2,090,250 for similar compounds; this conversion is exemplified herein in Example 1 steps D and E and Example 2. Alkylation of Compound V with chlorodifluoromethane produced the N-difluoromethyl derivative VI which was demethylated at the ether linkage upon treatment with boron tribromide in methylene chloride to give the corresponding phenol VII. Alkylation of the 5-hydroxyphenyl compound with propargyl bromide in the presence of potassium carbonate and acetone produced the present compound.

Preparation of the present compounds and the intermediate compounds shown in the chemical equations above is illustrated further in the following examples.. All temperatures shown are in degrees

Celsius, and reduced pressures for concentration of liquid were produced by a vacuum pump.

Example 1 PREPARATION OF INTERMEDIATES A. 4-Chloro-2-fluoro-5-methoxyphenylhydrazine

A stirred solution of 48.0 g (0.27 mole) of 4-chloro-2-fluoro-5-methoxyaniline in 50 mL of concentrated hydrochloric acid was cooled to -5°C, and 23.5 g (0.34 mole) of sodium nitrite in 100 mL of water was added dropwise. Upon complete addition, the reaction mixture was stirred at 0°C for one hour. A solution of 154.0 g (0.68 mole) of stannous chloride in 225 mL of concentrated hydrochloric acid was cooled to 0°C, and the cold solution prepared above, was slowly added to it. Upon complete addition, the reaction mixture was allowed to warm to ambient temperature, then was filtered to collect a solid. The solid was made basic and extracted with toluene. The toluene layer was separated and dried over magnesium sulfate, then filtered. The filtrate was concentrated under reduced pressure to give 22.4 g of 4-chloro-2-fluoro-5-methoxyphenylhydrazine as a solid. The nmr spectrum was consistent with the proposed structure. B. Pyruvic acid, 4-chloro-2-fluoro-5-methoxyphenylhydrazone

A stirred solution of 21.0 g (0.11 mole) of 4-chloro-2-fluoro-5-methoxyphenylhydrazine and 100 mL of aqueous 101 hydrochloric acid in 100 mL of ethanol was warmed to 40°C, and a solution of 10.0 g (0.114 mole) of pyruvic acid in 20 mL of water was added. Upon complete addition, the reaction mixture was stirred for one hour. An additional 50 mL of water was added, and the reaction mixture was filtered to collect a solid. The solid was air dried to give 29.0 g of pyruvic acid, 4-chloro-2-fluoro-5-metboxyphenyl hydrazone; mp 166-169°C.

The nmr spectrum was consistent with the proposed structure.

C. 1-(4-Chloro-2-fluoro-5-methoxyphenyl)-3-methyl- Δ²-1,2,4-triazolin-5-one.

A stirred solution of 27.0 g (0.104 mole) of pyruvic acid, 4-chloro-2-fluoro-5-methoxyphenylhydrazone, 29.0 g (0.105 mole) of diphenylphosphoryl azide, and 11.0 g (0.108 mole) of triethylamine in 500 mL of toluene was heated under reflux for four hours.

The reaction mixture was cooled to ambient temperature and extracted with aqueous 10% sodium hydroxide. The aqueous layer was separated and neutralized with gaseous carbon dioxide, and a solid was collected by filtration. The solid was air-dried to give 11.0 g of 1-(4-chloro-2-fluoro-5-methoxyphenyl)-3-methyl-Δ²- 1,2,4-triazolin-5-one; mp 193-195°C.

The nmr spectrum was consistent with the proposed structure. D. 1-(4-Chloro-2-fluoro-5-methoχγphenyl)-3-methyl-4-difluoroutethyl-Δ²-1,2,4-triazolin-5-one.

A stirred mixture of 10.0 g (0.039 mole) of 1-(4-chloro-2-fluoro-5-methoxyphenyl)-3-methyl-Δ²-1,2,4-triazolin-5-one, 10.0 g (0.031 mole) of tetrabutylammonium bromide, and 10.0 g (0.25 mole) of sodium hydroxide in 250 mL of cyclohexane was warmed to 60°C, and 10.0 g (0.116 mole) of chlorodifluororaethane was bubbled into the reaction mixture. Upon complete addition, the reaction mixture was warmed to reflux temperature and stirred for one hour. The hot solution was decanted from a pot residue and was allowed to cool to ambient temperature. Methylene chloride was added to the cooled mixture to dissolve a solid precipitate, and the whole was washed with aqueous 10% hydrochloric acid, then with aqueous 10% sodium hydroxide. The organic layer was separated and dried over magnesium sulfate, then filtered. The filtrate was concentrated under reduced pressure to give 5.0 g of 1-(4-chloro-2-fluoro-5-methoxyphenyl)-3-methyl-4-difluoromethyl-Δ²-1,2,4-triazolin-5-one; mp 86-88°C.

The nmr spectrum was consistent with the proposed structure.

E. 1-(4-Chloro-2-fluoro-5-hydroxyphenyl)-3-methyl-4-difluororaethyl-Δ²-1,2,4-triazolin-5-one. A stirred solution of 4.6 g (0.015 mole) of 1- (4-chloro-2-fluoro-5-methoxvphenyl)-3-methyl-4-difluoromethyl-Δ²-1,2,4-triazolin-5-one in 200 mL of methylene chloride was cooled to 10ºC, and a solution of 11.2 g (0.045 mole) of boron tribromide in 45 mL of methylene chloride was added. Upon complete addition, the cooling bath was removed, and the reaction mixture was stirred for four hours as it warmed to ambient temperature. Water (100 mL) was added and stirring was continued for an additional 18 hours. The organic layer was separated, dried over magnesium sulfate, and filtered. The filtrate was concentrated under reduced pressure to give 4.4 g of 1-(4-chloro-2-fluoro-5-hydroxyphenyl-3-methyl-4-difluoromethyl-Δ²-1,2,4-triazolin-5-one; mp 147-152°C. The nmr spectrum was consistent with the proposed structure.

Example 2

PREPARATION OF 1-(4-CHLORO-2-FLUORO-5- PROPARGYLOXYPHENYL)-3-METHYL-4-DIFLUOROMETHYL- Δ²-1,2.4-TRIAZOLIN-5-ONE

To a stirred mixture of 0.7 g (0.0023 mole) of

1-(4-chloro-2-fluoro-5-hydroχγphenyl)-3-methyl-4-difluoromethyl-Δ²-1,2,4-triazolin-5-one and 0.2 g (0.0015 mole) of potassium carbonate in 50 mL of acetone was added 0.3 g (0.0025 mole) of propargyl bromide. Upon complete addition, the reaction mixture was heated at reflux for three hours, then concentrated under reduced pressure. The residue was dissolved in methylene chloride and washed with water and aqueous 10% sodium hydroxide. The organic layer was dried over magnesium sulfate and filtered. The filtrate was concentrated under reduced pressure to give 0.33 g of 1-(4-chloro-2-fluoro-5-propargyloxyphenyl)-3-methyl-4-difluoromethyl-Δ²-1,2,4- triazolin-5-one as an oil. A sample of this material was employed in the herbicidal efficacy tests described below.

The nmr spectrum was consistent with the proposed structure. The reaction above was repeated with a purer sample of 1-(4-chloro-2-fluoro-5-hydroxyphenyl)- 3-methyl-4-difluoromethyl-Δ²-1,2,4-triazolin-5-one

(mp 158- 162°C) to give the desired propargyloxy derivative as a solid, mp 75-78°C. The nmr spectrum was consistent with the proposed structure.

A sample of product prepared in a similar manner was purified for microanalysis, mp 82-85°C.

Analysis for C₁₃H₉ClF₃N₃O₂: Calc'd: C 47.07, H 2.73, N 12.67;

Found: C 46.86, H 2.47, N 12.48.

Example 3

PREPARATION OF 1-[4-CHLORO-2-FLUORO-5-(1- METHYLETHOXY)PHENYL]-3-METHYL-4-DIFLUOROMETHYL- Δ²-1,2,4-TRIAZOLIN-5-ONE

This compound was prepared in a manner analogous to Example 2 using 0.50 g (0.0017 mole) of

1-(4-chloro-2-fluoro-5-hydroxyphenyl)-3-methyl-4-difluoromethyl-Δ²-1,2,4-triazolin-5-one, 0.36 g (0.0021 mole) of 2-iodopropane, and 0.71 g (0.0051 mole) of potassium carbonate in 50 mL of acetone. The yield of 1-[4-chloro-2-fluoro-5-(1-methylethoxy)-phenyl]-3-methyl-4-difluoromethyl-Δ²-1,2,4-triazolin- 5-one was 0.40 g; m.p. 77-79C.

The nmr spectrum was consistent with the proposed structure.

Example 4 PREPARATION OF 1-[4-CHLORO-2-FLUORO-5- (1-METHYL-2-PROPYNYLOXY)PHENYL]-3-METHYL-4- DIFLUOROMETHYL-Δ²-1,2,4-TRIAZOLIN-5-ONE This compound was prepared in a manner analogous to Example 2 using 05.0 g (0.0017 mole) of

1-(4-chloro-2-fluoro-5-hydroxyphenyl)-3-methyl-4-difluoromethyl-Δ²-1,2,4-triazolin-5-one, 0.28 g

(0.0021 mole) of 3-bromo-1-butyne, and 0.36 g (0.0021 mole) of potassium carbonate in 50 mL of acetone. The yield of 1-[4-chloro-2-fluoro-5-(l-methyl-2-propynyloxy)phenyl]-3-methyl-4-difluoromethyl-Δ²-1,2,4triazolin-5-one, as an oil, was 0.35 g.

The nmr spectrum was consistent with the proposed structure.

Analysis for C₁₄H₁₁CIF₃N₃O₂:

Calc'd: C 48.64, H 3.21, N 12.15;

Found: C 48.39, H 3.32, N 11.95.

Example 5 PREPARATION OF 1-(4-CHLORO-2-FLUORO-5-METHOXYMETH¬

OXYPHENYDL)-3-METHYL-4-DIFLUOROMETHYL-Δ²-1,2,4- TRIAZOLIN-5-ONE

This compound was prepared in the manner of

Example 2 using 0.75 g (0.0026 mole) of 1-(4-chloro-2-fluoro-5-hydroxyphenyl)-3-methyl-4-difluoromethyl-Δ²-1,2,4-triazolin-5-one, 0.21 g (0.026 mole) of chloromethyl methyl ether, and 0.35 g (0.0026 mole) of potassium carbonate in 60 mL of acetone. The yield of

1-(4-chloro-2-fluoro-5-methoxymethoxyphenyl)- 3-methyl-4-difluoromethyl-Δ²-1,2,4-triazolin-5-one, as an oil, was 0.84 g. The nmr spectrum was consistent with the proposed structure.

.Analysis for C₁₂H₁₁ClF₃N₃O₃:

Calc'd: C 42.68, H 3.28, N 12.44; Found: C 42.59, H 3.42, N 12.33.

Example 6

PREPARATION OF 1-(4-CHLORO-2-FLUORO-5-ALLYL¬

OXYPHENYL)-3-METHYL-4-DIFLUOROMETHYL-Δ²-1,2,4- TRIAZOLIN-5-ONE This compound was prepared in the manner of

Example 2 using 0.75 g (0.0026 mole) of 1-(4-chloro¬

2-fluoro-5-hydroxyphenyl)-3-methyl-4-difluoromethyl- Δ²-1,2,4-triazolin-5-one, 0.31 g (0.0026 mole) of allyl bromide, and 0.35 g (0.0026 mole) of potassium carbonate in 60 mL of acetone. The yield of 1-(4- chloro-2-fluoro-5-allyloxyphenyl)-3-methyl-4-difluoromethyl-Δ²-1,2,4-triazolin-5-one was 0.85 g; m.p.

53-55°C.

The nmr spectrum was consistent with the proposed structure.

Analysis for C₁₃H₁₁ClF₃N₃O₂:

Calc'd: C 46.64, H 3.21, N 12.45; Found: C 46.79, H 3.32, N 12.59.

Example 7 PREPARATION OF 1-[4-CHLORO-2-FLUORO-5-(l-METHYL-2- METHOXYETHOXY)PHENYL] -3-METHYL-4-DIFLUOROMETHYL- Δ²-1,2,4-TRIAZOLIN-5-ONE

A stirred mixture of 0.45 g (0.0015 mole) of

1-(4-chloro-2-fluoro-5-hydroxyphenyl)-3-methyl-4-difluoromethyl-Δ²-1,2,4-triazolin-5-one and 0.41 g

(0.0017 mole) of sodium hydride in 8 mL of dimethylformamide was warmed to 90ºC. The reaction mixture was cooled to 40ºC, and 0.37 g (0.0015 mole) of the tosylate of methoxypropan-2-ol was added in one portion. The reaction mixture was heated at temperatures varying from 40° to 140°C, then was allowed to cool to ambient temperature and was stirred for 16 hours. The reaction mixture was partitioned between water and methylene chloride. The methylene chloride layer was washed sequentially with aqueous 10% sodium hydroxide, aqueous 10% hydrochloric acid, and water. The organic layer was dried with magnesium sulfate and filtered. The filtrate was concentrated under reduced pressure to give 0.38 g of 1-[4-chloro-2-fluoro-5-(1-methyl- 2-methoxyethoxy)phenyl]-3-methyl-4-difluoromethyl-Δ²-1, 2,4-triazolin-5-one as an oil.

The nmr spectrum was consistent with the proposed structure.

Herbicidal Activity

Herbicidal efficacy data are given in Tables 1-5 below for the present compound of formula 1(a)

(Example 2) and the 2-chloro analog of that compound.

The 2-chloro compound i s 1- ( 2 , 4-dichloro- 5-propargyloxyphenyl)-3-methyl-4-difluoromethyl-Δ²-1,2,4-triazolin-5-one and is disclosed in British Patent No. 2,090,250, supra. While the present compound 1(a) differs structurally from the known compound only in having a fluorine atom instead of chlorine at the C-2 position of the phenyl ring, it was markedly and unexpectedly more active than the prior compound against a variety of broadleaf plant species in both preemergence and postemergence applications in side-by-side tests conducted as described below. Data for the compounds of Examples 3-7 are given in Tables 6 and 7. The plant species employed in these tests were selected from the following:

Common Name (Abbrev.) Scientific Name

Barnyardgrass (Barngr) Echinochloa crus galli

Field Bindweed (Bindweed) Convovulus arvensis Blue Panicum (Blue Pan) Panicum antidotale

Common Cocklebur (Coclebr) Xanthium pensylvanicum Field Corn (Corn) Zea mays Cotton Gossypium hirsutum

Giant Foxtail (Giantfox) Setaria faberi Herrm. Green Foxtail (Greenfox) Setaria viridis Ivyleaf Morningglory (Ivyglory) Ipomoea hederacea (L.) or Ipomoea lacumosa

Johnsongrass (Johngr) Sorghum halepense

Rice Oryza sativa

Hemp Sesbania (Sesbania) Sesbania exaltata Raf. Sicklepod (Sicklepd) Cassia obtusifolia L.

Broadleaf Signalgrass (Signalgr) Brachiaria platyphylla

Soybean Glycine max

Velvetleaf (Velvetlf) Abutilon theophrasti

Wheat Triticum aestivum wild Mustard (Wmustard) Brassica kaber

Yellow Nutsedge (Yel Nuts) Cyperus esculentus

Yellow Foxtail (Yellowfox) Setaria lutescens (Weigel) Hubb.

Seeds or tubers of the plant test species were planted in furrows in steam sterilized sandy loam soil contained in disposable fiber flats. The flats had been filled to a depth of about 6.5 cm with the soil. A topping soil of equal portions of sand and sandy loam soil was placed uniformly on top pf each flat to a depth of approximately 0.5 cm.

The flats for the preemergence tests were watered, then drenched with the appropriate amount of a solution of the test compound in a mixture of acetone and water containing a small amount (up to 0.5% v/v) of sorbitan monolaurate emulsifier/solubilizer. The concentration of the test compound in solution was varied to give a range of application rates, generally 8.0 kg/ha and submultiples thereof. The flats were placed in a greenhouse and watered regularly at the soil surface for 21 days at which time phytotoxicity data were recorded.

The flats for the postemergence tests were placed in a greenhouse and watered for 8-10 days, then the foliage of the emerged test plants was sprayed with a solution of the test compound in acetone-water containing up to 0.5% sorbitan monolaurate. After spraying, the foliage was kept dry for 24 hours, then watered regularly for 21 days, and phytotoxicity data recorded. Herbicidal data are given in Tables 1 and 2 below for the present compound 1(a) and for 1-(2,4-dichloro- 5-propargyloxyphenyl)-3-methyl-4-difluoromethyl-Δ²-1,2,4-triazolin-5-one (Compound A). In these tables "V" is vigor, "K" is % kill, and "kg/ha" is kilograms per hectare. Vigor ratings vary from 0 to 5 and have the following meaning:

V = 5 = no chemical injury; plants normal

4 = slight injury; plants will or have already recovered 3 = moderate injury; plants expected to recover

2 = moderate to severe injury; plants are not expected to recover

1 = severe injury; plants will not recover

0 = dead plant TABLE 1

Compound I(a)* Preemergence Activity Rate of Application (kg/ha)

.5000 . 2500 . 1250 . 0625 . 0313 . 0156 Species V K V K V K V K V K V K

BARNGR 0 100 0 100 0 100 0 100 0 100 0 100

BINDWEED 0 100 0 100 0 100 4 90 4 80 4 70

BLUE PAN 0 100 0 100 0 100 0 100 0 100 0 100

COCKLEBR 0 100 2 90 2 90 3 30 3 0 5 0

CORN 0 100 0 100 0 100 0 100 0 100 3 70

COTTON 3 80 3 80 4 30 4 0 5 0 4 0 GIANTFOX 0 100 0 100 0 100 0 100 0 100 0 100 GREENF0X 0 100 0 100 0 100 0 100 0 100 0 100 TABLE 1 (Continued)

Compound I (a :)*

Preemergence Activity

Rate of Application (kg/ha)

.5 000 .2500 .1250 .0625 .0313 .0156

Species V K V K V K V K V K V K

IVYGLORY 0 100 0 100 0 100 3 90 3 70 3 0

JOHNGR 0 100 0 100 0 100 0 100 0 100 0 100

RICE 0 100 0 100 0 100 0 100 2 90 3 40

SESBANIA 0 100 0 100 3 90 0 100 3 50 4 0

SICKLEPD 0 100 0 100 1 95 3 10 4 0 4 0

SIGNALGR 0 100 0 100 0 100 0 100 0 100 3 80

SOYBEAN 0 100 0 100 0 100 0 100 3 90 3 80

VELVETLF 0 100 0 100 0 100 0 100 0 100 0 100

WHEAT 0 100 0 100 0 100 2 80 3 20 3 20

WMUSTARD 0 100 0 100 0 100 0 100 4 50 5 0

YEL NUTS 0 100 2 60 2 70 3 60 3 10 4 0

YELLOWFOX 0 100 0 100 0 100 0 100 0 100 3 70

*Compound I(a) is the compound of Example 2, 1-(4-chloro- 2-fluoro-5-propargyloxyphenyl)-3-methyl-4-difluoromethyl-Δ²-1,2,4-triazplin-5-one.

Compound A* Preemergence Activity Rate of Application (kg/ha)

. 5000 . 2500 . 1250 . 0625 . 0313 . 0156

Species V K V K V K V K V K V K

BARNGR 0 100 0 100 0 100 0 100 0 100 0 100

BINDWEED 0 100 0 100 4 0 4 0 5 0 5 0

BLUE PAN 0 100 0 100 0 100 0 100 0 100 0 100

COCKLEBR 3 90 3 80 4 80 4 80 5 0 5 0

CORN 0 100 0 100 0 100 0 100 2 70 2 70

COTTON 3 50 4 80 4 0 5 0 4 80 4 0

GIANTFOX 0 100 0 100 0 100 0 100 0. 100 0 100

GREENFOX 0 100 0 100 0 100 0 100 0 100 0 100

IVYGLORY 0 100 0 100 3 50 4 0 4 0 5 0

JOHNGR 0 100 0 100 0 100 0 100 0 100 0 100

RICE 0 100 0 100 0 100 1 95 0 100 0 100

SESBANIA 0 100 0 100 3 90 0 100 3 30 4 0

SICKLEPD 2 90 3 0 4 0 4 0 4 0 4 0

SIGNALGR 0 100 0 100 0 100 0 100 0 100 0 100

SOYBEAN 0 100 0 100 2 90 3 80 4 60 4 0

VELVETLF 0 100 0 100 0 100 0 100 0 100 0 100

WHEAT 0 100 0 100 0 100 3 70 3 50 4 0

WMUSTARD 0 100 0 100 4 0 5 0 5 0 5 0

YEL NUTS 0 100 2 80 2 60 3 40 3 0 4 0

YELLOWFOX 0 100 0 100 0 100 0 100 0 100 3 95 *Compound A is 1-(2,4-dichloro-5-propargyloxyphenyl)- 3-methyl-4-difluoromethyl-Δ²-1,2,4-triazolin-5-one.

TABLE 2

Compound I(a) *

Positemergence Activity

Rate of Applications (kg/ha)

.5000 .2500 .1250 .0625 .0313 .0156

Species V K V K V K V K V K V K

BARNGR 0 100 0 100 0 100 0 100 0 100 3 80

BINDWEED 0 100 0 100 0 100 0 100 0 100 3 90

BLUE PAN 0 100 0 100 0 100 0 100 0 100 2 90

COCKLEBR 0 100 2 90 3 90 4 0 5 0 5 0

CORN 0 100 0 100 0 100 1 60 2 30 2 60

COTTON 0 100 0 100 0 100 3 90 0 100 1 90

GIANTFOX 0 100 0 100 0 100 0 100 0 100 0 100

GREENFOX 0 100 0 100 0 100 0 100 0 100 2 90

IVYGLORY 0 100 0 100 0 100 0 100 0 100 2 80

JOHNGR 0 100 0 100 0 100 0 100 4 30 3 60

RICE 0 100 0 100 0 100 0 100 1 90 3 70

SESBANIA 0 100 0 100 0 100 0 100 0 100 2 90

SICKLEPD 0 100 0 100 1 90 0 100 3 30 3 40

SIGNALGR 0 100 0 100 0 100 0 100 0 100 2 90

SOYBEAN 1 90 0 100 1 90 2 70 3 60 3 30

VELVETLF 0 100 0 100 0 100 0 100 0 100 0 100

WHEAT 0 100 0 100 0 100 2 70 4 30 5 0

WMUSTARD 0 100 0 100 0 100 0 100 3 70 5 0

YEL NUTS 2 80 0 100 2 60 2 20 3 0 5 0

YELLOWFOX 0 100 0 100 0 100 0 100 0 100 0 100

*Compound I(a) is the compound of Example 2, 1-(4-chloro- 2-fluoro-5-propargyloxyphenyl)-3-methyl-4-difluororaethyl-Δ²-1,2,4-triazolin-5-one.

TABLE 2 (Continued)

Compound A*

Postemergence Activity

Rate of Application (kg/ha)

.5000 .2500 .1250 .0625 .0313 .0156

Species V K V K V K V K V K V K

BARNGR 0 100 0 100 0 100 3 80 3 70 0 100

BINDWEED 0 100 0 100 0 100 4 60 4 0 0 100

BLUE PAN 0 100 0 100 0 100 0 100 0 100 0 100

COCKLEBR 2 0 3 0 4 0 3 0 5 0 5 0

CORN 0 100 0 100 0 100 2 90 4 0 4 60

COTTON 0 100 0 100 0 100 0 100 0 100 3 30 TABLE 2 (Continued)

Compound A *

Postemergence Activity

Rate of Applications (kg/ha) .5000 .2500 .1250 .0625 .0313 .0156

Species V K V K V K V K V K V K GIANTFOX 0 100 0 100 0 100 0 100 0 100 0 100

GREENFOX 0 100 0 100 0 100 0 100 0 100 0 100

IVYGLORY 0 100 0 100 0 100 1 90 1 90 4 90

JOHNGR 0 100 0 100 0 100 0 100 4 30 1 90

RICE 0 100 0 100 0 100 0 100 1 90 2 90

SESBANIA 0 100 0 100 0 100 0 100 0 100 2 90

SICKLEPD 0 100 0 100 0 100 5 0 4 80 5 0

SIGNALGR 0 100 0 100 0 100 0 100 0 100 0 100

SOYBEAN 2 90 2 80 3 40 3 30 4 0 4 0

VELVETLF 0 100 0 100 0 100 0 100 2 90 0 100

WHEAT 0 100 3 80 2 70 4 10 4 20 5 0

WMUSTARD 0 100 3 20 5 0 5 0 5 0 5 0

YEL NUTS 2 90 2 60 3 0 3 30 4 0 4 0

YELLOWFOX 0 100 0 100 0 100 0 100 0 100 4 70

*Compound A is 1-(2,4-dichloro-5-propargyloxyphenyl)-3- methyl-4-difluoromethyl-Δ²-1,2,4-triazolin-5-one.

In order to better compare herbicidal activity for the two test compounds, biological efficacy (BE) figures were calculated from percent kill and vigor using the equation

BE = % kill + X(100 - % kill) wherein X is a number assigned to the vigor rating according to the following schedule: vigor X

0 1

1 1

2 0.75

3 0.25

4 0.12

5 0

Tables 3 and 4 below show BE values calculated from the data in Tables 1 and 2 above for the present compound 1(a) and the 2-chloro analog. BE values increase with herbicidal efficacy to a maxmimum value of 100.

TABLE 3

Compound I(a)*

Preemergence Biological Efficacy (BE)

Rate of Application (kg/ha)

.5000 .2500 .1250 .0625 .0313 .0156

Species BE BE BE BE BE BE

BARNGR 100 100 100 100 100 100

BINDWEED 100 100 100 91 82 74

BLUE PAN 100 100 100 100 100 100

COCKLEBR 100 98 98 48 25 0

CORN 100 100 100 100 100 78

COTTON 85 85 38 12 0 12

GIANTFOX 100 100 100 100 100 100

GREENFOX 100 100 100 100 100 100

IVYGLORY 100 100 100 93 78 25

JOHNGR 100 100 100 100 100 100

RICE 100 100 100 100 98 55

SESBANIA 100 100 93 100 63 12

SICKLEPD 100 100 100 33 12 12

SIGNALGR 100 100 100 100 100 85

SOYBEAN 100 100 100 100 93 85

VELVETLF 100 100 100 100 100 100

WHEAT 100 100 100 95 40 40

WMUSTARD 100 100 100 100 56 0

YEL NUTS 100 90 93 70 33 12

YELLOWFOX 100 100 100 100 100 78

*Compound I(a) is the compound of Example 2, 1-(4-chloro-2-fluoro-5-propargyloxyphenyl)-3-methyl-4-difluoromethyl-Δ²-1,2,4-triazolin-5-one.

Compound A*

Preemergence Biological Efficacy (BE)

Rate of Application (kg/ha)

.5000 .2500 .1250 .0625 .0313 .0156

Species BE BE BE BE BE BE

BARNGR 100 100 100 100 100 100 BINDWEED 100 100 12 12 0 0 BLUE PAN 100 100 100 100 100 100 COCKLEBR 93 85 82 82 0 0 CORN 100 100 100 100 93 93

COTTON 63 82 12 0 82 12 GIANTFOX 100 100 100 100 100 100 TABLE 3 (Continued)

Compound A *

Preemergence Biological Efficacy (BE)

Rate of Application (kg/ha)

.5000 .2500 .1250 .0625 .0313 .0156

Species BE BE BE BE BE BE

GREENFOX 100 100 100 100 100 100

IVYGLORY 100 100 63 12 12 0

JOHNGR 100 100 100 100 100 100

RICE 100 100 100 100 100 100

SESBANIA 100 100 93 100 48 12

SICKLEPD 98 25 12 12 12 12

SIGNALGR 100 100 100 100 100 100

SOYBEAN 100 100 98 85 65 12

VELVETLF 100 100 100 100 100 100

WHEAT 100 100 100 78 63 12

WMUSTARD 100 100 12 0 0 0

YEL NUTS 100 95 90 55 25 12

YELLOWFOX 100 100 100 100 100 96

*Compound A is 1-(2,4-dichloro-5-propargyloxyphenyl)- 3-methyl-4-difluoromethyyll-Δ²-1,2,4-triazolin-5-one.

TABLE 4

Compound I ( a)*

Postemergence Biological Efficacy

Rate of Application (kg/ha)

.5000 .2500 .1250 .0625 .0313 .0156

Species BE BE BE BE BE BE

BARNGR 100 100 100 100 100 85

BINDWEED 100 100 100 100 100 93

BLUE PAN 100 100 100 100 100 98

COCKLEBR 100 98 93 12 0 0

CORN 100 100 100 100 83 90

COTTON 100 100 100 93 100 100

GIANTFOX 100 100 100 100 100 100

GREENFOX 100 100 100 100 100 98

IVYGLORY 100 100 100 100 100 95

JOHNGR 100 100 100 100 38 70

RICE 100 100 100 100 100 78

SESBANIA 100 100 100 100 100 98

SICKLEPD 100 100 100 100 48 55

SIGNALGR 100 100 100 100 100 98

SOYBEAN 100 100 100 93 70 48

VELVETLF 100 100 100 100 100 100

WHEAT 100 100 100 93 38 0 TABLE 4 (Continued)

Compound I(a)* Postemergence Biological Efficacy

Rate of Application (kg/ha)

.5000 .2500 .1250 .0625 .0313 .0156

Species BE BE BE BE BE BE

WMUSTARD 100 100 100 100 78 0 YEL NUTS 95 100 90 80 25 0 YELLOWFOX 100 100 100 100 100 100

TABLE 4

Compound A*

Postemergence Biological Efficacy

Rate of Application (hg/ka)

.5000 .2500 .1250 .0625 .0313 .0156

Species BE BE BE BE BE BE

BARNGR 100 100 100 85 78 100

BINDWEED 100 100 100 65 12 100 BLUE PAN 100 100 100 100 100 100

COCKLEBR 75 25 12 25 0 0

CORN 100 100 100 98 12 65

COTTON 100 100 100 100 100 48

GIANTFOX 100 100 100 100 100 100

GREENFOX 100 100 100 100 100 100

IVYGLORY 100 100 100 100 100 91

JOHNGR 100 100 100 100 38 100

RICE 100 100 100 100 100 98

SESBANIA 100 100 100 100 100 98

SICKLEPD 100 100 100 0 82 0

SIGNALGR 100 100 100 100 100 100

SOYBEAN 98 95 55 48 12 12

VELVETLF 100 100 100 100 98 100

WHEAT 100 85 93 21 30 0

WMUSTARD 100 40 0 0 0 0

YEL NUTS 98 90 25 48 12 12

YELLOWFOX 100 100 100 100 100 74

*Compound A is 1-(2,4-dichloro-5-propargyloxyphenyl)-3-methyl-4-difluoromethyl-Δ²-1,2,4-triazolin-5-one.

Table 5 below shows a comparison of the average or overall biological efficacy for the present compound I(a) and the prior art compound against both weed grasses and weed broadleaves. The BE values for grasses represent the average of the BE values in Table 3 (preemergence) or Table 4 (postemergence) for barnyardgrass, blue panicum, giant foxtail, green foxtail, johnsongrass, signalgrass, yellow nutsedge, and yellow foxtail. The BE values for broadleaves represent the average for bindweed, cocklebur, ivyglory, sesbania, sicklepod, velvetleaf, and wild mustard.. As can be seen from the table, both compounds performed equally well against the grasses, but the present compound was substantially more active against the more difficult to control broadleaves. In the preemergence tests against broadleaves, 0.5 kg/ha of the standard compound was needed for a BE of 99, whereas only 0.125 kg/ha of the present compound was required for the same level of control. Similarly, in the postemergence tests, 0.5 kg/ha of the standard gave a BE value of 96 while the present compound gave a BE of 99 at one-fourth the application rate, 0.125 kg/ha. Thus, in either preemergence or postemergence applications against the broadleaves, the present compound was about four times as active as the 2-chloro compound.

For the compounds of Examples 3-7, phytotoxicity data were taken as percent control. Percent control was determined by a method similar to the 0 to 100 rating system disclosed in "Research Methods in Weed Science," 2nd ed. , B. Truelove, Ed.; Southern Weed Science Society; Auburn University, Auburn, Alabama, 1977. The present rating system is as follows:

Herbicidal data at selected application rates are given for the compounds of Examples 3-7 in Tables 6 and 7 below. The test compounds are identified in the tables by Example numbers. In the tables "kg/ha" is kilograms per hectare and "% C" is percent control. *The compound number is the number of the Example in which the particular compound was prepared.

For herbicidal application, the active compounds as above defined 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, 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.

For preemergence application these herbicidal compositions are usually applied either as sprays, dusts, or granules to the areas in which suppression of vegetation is desired. For postemergence control of established plant growth, sprays or dusts are most commonly used. These formulations may contain as little as 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 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 dilutents. 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 formulation 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 a.s wetting agents. Frequently, additional wetting agent and/or oil will be added to the tank-mix for post-emergence application to facilitate dispersion on the foliage and absorption by the plant.

Other useful formulations for herbicidal applications are emulsifiable concentrates. Emulsifiable concentrates 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.

Typical wetting, dispersing or emulsifying agents used in agricultural formulations include, for example, the alkyl and alkylaryl sulfonates and sulfates and their sodium salts; polyhydric alcohols; and other types of surface active agents, many of which are available in commerce. The surface active agent, when used, normally comprises 1% to 15% by weight of the herbicidal composition.

Other useful formulations for herbicidal applications include simple solutions of the active ingredient in a dispersant 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. These soluble or dispersible granular formulations described in U.S. patent No. 3,920,442, incorporated herein by reference are useful herein with the present herbicidal compounds.

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 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 herbicides such as 2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl)acetamide (alachlor), 2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-l-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-di-chlorophenyl)-N,N-dimethylurea (diuron) and N,N-dimethyl-N'-[3-(trifIuoromethyl)phenyl]urea (fluometuron).

In general, the compounds of this invention having the formula

in which R is a radical selected from 2-propynyl, 1-methylethyl, 1-methyl-2-propynyl, methoxymethyl, 2-propenyl, and 1-methyl-2-methoxyethyl, may be prepared by (a) reacting the compound of the formula

with R-X, in which R is as defined above and X is a good leaving group, in the presence of a base, or alternatively, (b) reacting a compound of the formula

in which R is as defined above, with CHF₂-X, in which X is a good leaving group, in the presence of a phase transfer catalyst and a base selected from sodium hydroxide and potassium hydroxide. The leaving group X is a chlorine, bromine or iodine atom. When practicing method (a) the base is an alkali metal carbonate, or alkali metal bicarbonate, or an alkali metal hydride, and in method (b) the phase transfer catalyst is a tetralkylammonium halide and the base is sodium hydroxide. In method (a) the base can be sodium carbonate or potassium carbonate and in method (b) the phase transfer catalyst is a tetrabutylammonium halide or a (triethyl)(benzyl)ammonium halide in which the halide is bromide or chloride.

Claims

Claims:

1. A compound of the formula

in which R is a radical selected from 2-propynyl, 1-methylethyl, 1-methyl-2-propynyl, methoxymethyl, 2-propenyl, and 1-methyl-2-methoxyethyl.

2. An herbicidal composition characterized by an herbicidally effective amount of the compound of claim 1 in admixture with a suitable carrier.

3. A method for controlling undesired plant growth characterized by applying to the locus where control is desired an herbicidally effective amount of the composition of claim 2.

4. An herbicidal composition characterized by an herbicidally effective amount of compound of the formula

in which R is a radical selected from 2-propynyl,

1-methylethyl, 1-methyl-2-propynyl, methoxymethyl,

2-propenyl, and 1-methyl-2-methoxyethyl.

5. A method for controlling undesired plant growth characterized by applying to the locus where control is desired an herbicidally effective amount of the composition of claim 4.

6. A process for producing a compound of the formula

in which R is a radical selected from 2-propynyl, 1-methylethyl, 1-methyl-2-propynyl, methoxymethyl, 2-propenyl, and 1-methyl-2-methoxyethyl, characterized by (a) reacting the compound of the formula

with R-X, in which R is as defined above and X is a good leaving group, in the presence of a base, or alternatively,

(b) reacting a compound of the formula

in which R is as defined above, with CHF₂-X, in which.

X is a good leaving group, in the presence of a phase transfer catalyst and a base selected from sodium hydroxide and potassium hydroxide.

7, The process of claim 6 characterized in that X is a chlorine, bromine, or iodine atom.

8. The process of claim 7 characterized in that in method (a) the base is an alkali metal carbonate, an alkali metal bicarbonate, or an alkali metal hydride, and in method (b) the phase transfer catalyst is a tetraalkylammonium halide and the base is sodium hydroxide.

9. The process of claim 8 characterized in that in method (a) the base is sodium carbonate or potassium carbonate and in method (b) the phase transfer catalyst is a tetrabutylammonium halide or a (triethyl) (benzyl)ammonium halide in which halide is bromide or chloride.