CA1246589A

CA1246589A - Herbicidal 1-aryl-.delta..sup.2-1,2,4-triazolin-5-ones

Info

Publication number: CA1246589A
Application number: CA000476790A
Authority: CA
Inventors: Lester L. Maravetz
Original assignee: FMC Corp
Current assignee: FMC Corp
Priority date: 1984-03-29
Filing date: 1985-03-18
Publication date: 1988-12-13
Also published as: AU566839B2; IL74737A0; HU194703B; BR8506209A; HUT38220A; IT8520115A0; AU4115485A; IT1200433B; WO1985004307A1; EP0177553A4; EP0177553A1

Abstract

Abstract: HERBICIDAL 1-ARYL-.DELTA.2-1,2,4-TRIAZOLIN-5-ONES Novel aryltriazolinone compounds of the formula wherein R is alkyl, alkenyl, alkynyl, alkoxyalkyl, or alkyl-S(O)n-alkyl wherein n is 0 to 2 are disclosed as having herbicidal utility against a variety of grassy and broadleaf weeds in both preemergence and postemer-gence applications and are exemplified by the species wherein R is 2-propynyl, 1-methylethyl, 1-methyl-2-pro-pynyl, methoxymethyl, 2-propenyl, and 1-methyl-2-methoxyethyl.

Description

~%~6589 HERBICIDAL l-ARYL-~-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 5 unwanted plant growth. More specifically, the present application describes novel herbicidal l-ary~2-1,2,4-triazolin-5-ones, herbicidal composi~ions containing ~he new compounds, methods for preparing the compounds, and methods for preYenting or 10 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 o~ or destroy a variety of weeds.
Various herbicidal l^aryl-A2-1,2,4-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 Cl O

Cl~

wherein Rl is alkyl, ~2 is hydrogen, alkyl, or alkenyl, and X is hydroxy, alkyl, alkoxy, alkoxy-alkoxy, alkenyloxy, or alkyloxycarbonylalkyloxy.
British Patent No. 2,090,250, adds to the above :
" ,, ,.,~

12~658~
, 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 F O

~N

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

wherein R is hydrogen, alkyl, or 2-propenyl, and is methyl or alkoxy.
South African Patent Application No. 78/3182 discloses herbicidal aryltriazolinones of the formula Rn ~ ~ - Rl wherein Rn is hydrogen or represents 1 to 4 same or different radicals selected from halogen, nitro, cyano, optionally halo substituted alkyl, alkoxy, or s~9 alkylthio, and optionally substituted phenyl or phenoxy, an~ Rl is alkyl5 alkoxyalkyl, dialkoxy-ethyl, dialkylaminoethyl, or cycloalkyl.
U.S. Patent No. 4,315,767 discloses herbicidal bicyclic compounds of the following formula . Y Q

lo J~,~ ( C~2~n 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 sulur, and Z is oxygen, S(O)p, or NRl wherein p is 0-2 and R 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 Y Q
~ Nf--~
(CH2~n tCH3)m wherein V is hydrogen, halogen, hydroxy, alkyl, or -ORl; Rl is optionally substituted alkyl, cycloalkyl, cycloalkylalkyl, optionally substituted alkenyl, alkynyl, optionally substituted benzyl, alkylaminocarbonyl, (alkyl)(methyl or methoxy)amino-carbonyl, acyl, alkoxycarbonyl, or -CHR7R8 wherein R7 is hydrogen or alkyl and :R8 is cyano, acetyl, ~24~589 hydroxycarbonyl, alkoxycarbonyl~ hydroxymethyl, alkoxymethyl, alkylcarbonyloxymethyl, hydroxycarbonyl-ethenyl, alkoxycarbonylethenyl, or a group -CO-NRllR12 wherein Rll is hydrogen, alkyl, alkenyl, or alkoxy, and R12 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, ~ith certain provisos.
A class of ~2-1,2,4-triazolin-5-ones is disclosed as fungicides in U.S. 4,~98,896. The disclosed genus has the formula ~1_ S ~ ~ R
N 1~ 2 SR

wherein R is alkyl, alkenyl, alkynyl, cycloalkyl, or optionally substituted phenyl or arylalkyl, Rl is haloalkyl or haloalkenyl, and R is optionally sub-stituted 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-methyl-4-difluoromethyl-~2-1,2,4-triazolin-5-ones of the formula Cl ~ - CHF2 I

P~C) CH 3 wherein R is alkyl, alkenyl, alkynyl, alkoxyalkyl, or alkyl S~O)n-alkyl wherein n is 0 to 2.

, . . .

-iL2~5~

The present compounds are named in accordance wi~h the numbering system shown in formula I, for the ring atoms of the heterocycle which is the same as ~he numbering system used in V.S. 4,318,731, supra, for 5 similar compounds.
A preferred embodiment of this invention is 1-(4-chloro-2-fluoro-~ propargyloxyphenyl)-3-methyi-4-difluoromethyl-~2-1,2,4-triazolin-5-one, the compound oE the formula F

Cl ~ CHF2 ~a) ~C_CCH20 CH3 Other pre~erred embodiments include the compounds of formula I in which R is -CH3, -CH(CH3)2, -CH(C~3)C-CH, -CH20CH3, -CH2CH=CH2, and -CH(CH3)CH2OCH3-The present compounds, which have a fluorine atom 20 at the C-2 position of the phenyl ring, in ~eneral have herbicidal properties far superior to those of the correspondin~ 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 25 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 co~pounds or by methods 30 within the skill of the art. A method of preparation exemplified herein is illustrated in the following chemical equations for the compound of formula I(a).

j - ~2~i5~3~

Cl NaN02/HC1 C1 C~30~ F sncl2-2EJ2o/Elc~ H3CO--~ F
NH2 ~5 to 09C NHNH2 II III
.
C1 ,, III ~ Cll CCOOII lOX HClH3Co--~ F
EtOH
40C NH-N=&CH

IV (00)2P(O)N3 ~ Cl ~
~CH3 OC~3 C113 re1ux V
CHC1F2 F ~ o NaOII/TlSAB ~ Cl~ N~N CHF2 cyclohexane 0 3 N 1~
ref 1ux CH3 VI

VI CH2C12 ~ C1--~ Nh~CHF2 VII
P O
~rClt2(:_(:11 ~ ~11 VII ~C2C03 ~ Cl~ CH1~`2 ref luxF ` OCH2C-CH C~13 I(~,~

65~3~

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-propar-5 gyloxyaniline as the starting material in place ofcompound II (the corresponding ~-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.
10 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 oE 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 - ~o I(a) in three steps by methods analo~ous 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 abo~e is illustrated further in the following examples. All temperatures shown are in degrees Celsius, and reduced pressures for concentration of - 8 - ~ 5~

liquid were produced by a vacuum pump.

Example 1 PREPARATION OF INTERMEDIATES AND l-(4-CHLORO-2-FLUORO-5-METHOXYPHENYL)-3-METHYL-4-DIFLUORO-MET~YL-~2-1,2,4-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 con-centrated 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 0C for one hour~
A solution of 154.0 g (0.68 mole) of stannous chlor-ide in 225 mL of concentrated hydrochloric acid was cooled to 0C, 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 ~iltered to collect a solid.
The solid was made basic and extracted with toluene.
The toluene layer was separated and dried over mag-nesium 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-methoxyphenyl-hydrazone A stirred solution of 21.0 g (0.11 mole) of 4-chloro-2-fluoro-5-methoxyphenylhydrazine and 100 mL
of aqueous 10% hydrochloric acid in 100 mL of ethanol was warmed to 40C, 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 methoxyphenyl-i58~

g hydrazone; mp 166-169C.
The nmr spectrum was consistent with the proposed structure.
C. 1-(4-Chloro-2-fluoro-5-methoxyphenyl)-3-methyl-5 ~2-1,2,4-triazolin-5-one.
A stirred solution of 27.0 g (0.104 mole) of pyruvic acid, 4-chloro-2-fluoro-5-methoxyphenyl-hydrazone, 29.0 g (0.105 mole) of diphenylphosphoryl azide, and 11.0 g ~0.108 mole) of triethylamine in 500 10 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 lay~r was separated and neutralized with gaseous carbon dioxide, and a solid was collected by 15 filtration. The solid was air-dried to give 11.0 g of 1-(4-chloro-2-fluoro-5-methoxyphenyl)-3-methyl-~2-1,2,4-triazolin 5-one; mp 193-195C~
The nmr spectrum was consistent with the proposed structure.
20 D. 1-(4-Chloro-2-fluoro-5-methoxyphenyl)-3-methyl-4-difluoromethyl-~2-1,2,4-triazolin-5-one.
A stirred mixture of 10.0 g (0.~39 mole) of 1-(4-chloro-2-fluoro-5-methoxyphenyl)-3-methyl-A2-1,2,4-triazolin-5-one, 10.0 g (0.031 mole) of tetrabutyl-25 ammonium bromide, and 10.0 g (0.25 mole) of sodiumhydroxide in 250 mL of cyclohexane was warmed to 60C, and 10.0 g (0.116 mole) of chlorodifluoromethane was bubbled into the reaction mixture. Upon complete addition, the reaction mixture was warmed to reflux 30 temperature and stirred for one hour. The hot solu-tion 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%
35 hydrochloric acid, then with aqueous 10% sodium hydroxide. The organic layer was separated and dried 1~6589 over magnesium sulfate, then filtered. The filtrate was concentrated under reduced pressure to give 5.0 g of 1-(4-chloro-2-fluoro-5-me~hoxyphenyl)-3-methyl-4-difluoromethyl-~2-1,2;4-triazolin-5-one, mp 5 86-88C.
The nmr spectrum was consistent with the proposed structure.
E. 1-(4-Chloro-2-fluoro-5-hydroxyphen~ 3-methyl-4-di-fluoromethyl-~2-1,2,4-triazolin-5-one.
A stirred solution of 4.6 g (0.015 mole) of 1-(4-chloro-2-fluoro-5-methoxyphenyl)-3-methyl-4-difluoro-methyl-~2-1,2,4-triazolin-S-one in 200 mL of methylene chloride was cooled to 10G, and a solution of 11.2 g (0.045 mole) of boron tribromide in 45 mL of 15 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 20 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-~2-1,2,4-triazolin-S-one; mp 147-152C.
The nmr spectrum was consistent with the proposed structure.

Fxample 2 PREPARATION OF 1-(4-CHLORO-2-FLUORO-5-PROPARGYLOXYPHENYL)-3-METHYL-4-~IFLUOROMETHYL-2 ~,4-TRIAZOLIN-5-ONE _ _ To a stirred mixture of 0.7 g t0.0023 mole) of 1-(4-chloro-2-fluoro-5-hydroxyphenyl)-3-methyl-4-di-fluoromethyl-~2-1,2,4-triazolin-5-one and 0.2 g 35 (0.0015 mole) of potassium carbonate in 50 ~L of acetone was added 0.3 g (0.0025 mole) of propargyl - ~2~6S~g bromide. Upon complete addition, the reaction mixture ~as heated at reflux for three hours, then concentrat-ed under reduced pressure. The residue was dissolved in methylene chloride and washed with water and aqueous 10% sodium hydroxide. The ~r~anic 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-propar-gyloxyphenyl)-3-methyl-4-difluoromethyl-~ -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-Q2-1,2,4-triazolin-5-one (mp 158- 162C) to give the desired propargyloxy derivative as a solid, mp 75 78C.
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 C13H9ClF3N32 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-MET~YLETHOXY)PHENYL]-3-METHYL-4-DIFLUOROMETHYL-Q -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-di-fluoromethyl-Q -1,2,4-tria~olin-5-one, 0.36 g (0.0021 mole) of 2-iodopropane, and 0.71 g (0.0051 mole) of potassium car~onate in 50 mL of acetone. The 2~Sl5 ~

yield of 1-[4-chloro-2-fluoro-5-(1-methylethoxy)-phenyll-3-methyl-4-difluoromethyl -a 2-1,2,4-triazolin-5-one was 0.40 ~; m.p. 77-79C.
The nmr spectrum was consistent with the proposed structure.
Example 4 - PREPARATION OF 1-[4-CHLORO-2-FLUORO-5-(l-METHYL-2-PROPYNYLOXY)PHENYL]-3-METHYL-4-DIFLUOROMETHYL-~2-1 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-di-fluoromethyl-a2-1,2,4-triazolin-5-one, 0.28 g (0.0021 mole) of 3-bromo-1-butyne, and 0.36 g (0.0021 15 mole) of potassium carbonate in 50 mL of acetone. The yield of 1-[4-chloro-2-fluoro-5-~1-methyl-2-propynyl-oxy)phenyl]-3-methyl-4-difluoromethyl ~2-1,2,4-triazolin-5-one, as an oil, was 0.35 g.
The nmr spectrum was consistent with the proposed 20 structure.
y is for Cl4HllClF3N32 Calc'd: C 48.64, H 3.21, N 12.15;
Found: C 48.39j H 3.32, N ll.9S.
Example 5 PREPARATION OF 1-(4-CHLORO-2-FLUORO-5-METHOXYMETH-OXYPHENYL)-3-METHYL-4-DIFLUOROMETHYL-~2-1,2,4-This compound was prepared in the manner of Example 2 using 0.75 g (0.0026 mole) of 1-(4-chloro-30 2-fluoro-5-hydroxyphenyl)-3-methyl-4-difluoromethyl--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)-35 3-methyl-4-difluoromethyl-a2-1,2,4-triazolin-5-one, as an oil, was 0.84 g.

~2~5~9 The nmr spectrum was consistent with the proposed structure.
y s for C12HllClF3N33 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-~2-1,2,4-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-~2-1,2,4-triazolin-5-one, 0.31 g (0.0026 mole) of allyl bromide, and 0.35 g (Q.0026 mole) of potassium 15 carbonate in 60 mL of acetone. The yield of 1-(4-chloro-2-fluoro-5-allyloxyphenyl)-3-methyl-4-difluoro-methyl-~2 1,2,4-triazolin-5-one was 0.85 g; m.p.
53-55C.
The nmr spectrum was consistent with the proposed 20 structure.
Analysis for C13HllClF3N32 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-(1-METHYL-2-METHOXYETHOXY)PHENYL]-3-METHYL-4-DIFLUOROMETHYL-~2-1,2,4-TRIAZOLIN-5-ONE
__ _ A stirred mixture of 0.45 g ~0.0015 mole) of 1-~4-chloro-2-fluoro-5-hydroxyphenyl)-3-methyl-4-30 difluoromethyl-~2-1,2,4-triazolin-5-one and 0.41 g ~0.0017 mole) of sodium hydride in 8 mL of dimethyl-formamide was war~ed to 90C. The reaction mixture was cooled to 40C, and 0.37 g (0.0015 mole) of the tosylate of methoxypropan-2-ol was added in one por-35 tion. The reaction mixture was heated at temperaturesvarying from 40 to 140C, tben was allowed to cool to 5~

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, 5 aqueous 10~ hydrochloric acid, and water. The organic layer was drled 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-10 ~ -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 - 15 below for the present compound of formula l(a) (Example 2) and the 2-chloro analog of that compound.
The 2-chloro compound is 1-(21~-dichloro-5-propar-gyloxyphenyl)-3-methyl-4-difluoromethyl-~2-1,2,4-triazolin-5-one and is disclosed in British Patent No.
20 2,090,250, supra. While the present compound l(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 25 against a variety of broadleaf plant species in both preemergence and postemergence applications in side-by-side tests conducted as described below. Data for t~e 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 35 Blue Panicum (Blue Pan) Panicum antidotale Common Cocklebur (Coclebr) Xanthium pensy~vanicum Field Corn (Corn) Zea mays Cotton Gossypium hirsutum Giant Foxtail (Giantfox) Set ria 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.
10 Sicklepod (Sicklepd) Cassia obtusifolia L.
Broadleaf Signalgrass (Signalgr) Brachiaria platyphylla Soybean Glycine max Velvetleaf (Velvetlf) Abutilon theophrasti Wheat Triticum aestivl~m 15 Wild Mustard (Wmustard) Brassica kaber Yellow Nutsedge tYel 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 of 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 5~9 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 ~onolaurate. After spraying, the foliage was kept dry for 24 hours, then watered regularly for 21 days, and phytotoxicity data recorded.
10Herbicidal data are given in Tables 1 and 2 below for the present compound I(a) and for 1-(2,4-dichloro-5-propargyloxyphenyl)-3-methyl-4-difluoromethyl-~-1,2,4-triazolin-5-one (Compound A). In these tables "V" is vigor, "K" is % kill, and "kg/ha" is kilograms per hectare. Vi~or 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 203 - moderate injury; plants expected to recorer 2 = moderate to severe injury; plants are not expected to recover 1 = severe injury; plants will not recover 0 = dead plant Compound I(a)~
Preemergence Activity Rate of Ap lication (k~/ha) .5000 .2500 -~ .1-2-5 ~ .0625 .0313 .0156 30 Species V K V K V K V K V K V K
BARNGR 0100 0100 0100 0100 0i00 0100 BINDWEED 0 100 0100 0l00 490 480 4 70 BLUE PAN 0 100 0100 0lQ0 0100 0100 0 100 ~2gL~i5~3~

TABLE 1 (Continued) Compound I(a)*
Pree~er~ence Activity Rate of Application (kg/ha) .S000.2500 .1250 .0525 .031-3 .01~6 Species V K V K Y ~ V K V K V K
_. _ _ _ _ _ IVYGLORY O 100 0 lOO O 100 3 90 3 70 3 0JOHNGR O100 0100 0100 0lOO O100 0100 RICE O100 0100 0lOO OlOO 290 340 SESBANIA O lOO O100 390 0lOO 350 4 0 SICKLEPD O lOO OlOO 195 310 40 4 0 WMUSTARD O lOQ O100 0100 0100 450 5 0 YEL NUTS O lOO 260 270 360 310 4 0 *Compound I(a) is the compound of Example 2, 1-~4-chloro-2-fluoro-5-propargyloxyphenyl)-3-methyl-4-difluoro-methyl-~ 2-1, 2,4-triazolin-5-one.
Compound A*
Preemer~gence ~ctivity Rate of Application ~kg/ha) .5000 .2500 .l~5b --~b~25 .0313 .01S6 Species V K V K V X V ~ V X V K
_ BARNGR OlOO O100 0lOO O100 0100 0100 CORN O100 0100 0100 0lOO 270 270 GREENFOX O 100 0100 0lOO O100 0100 0 100 RICE OlOO O100 0100 19S O100 0100 SESBANIA O 100 0100 390 0lOO 330 4 0 SIGNALGR O 100 0100 0100 0100 0100 0 lOO

VELVETLF O lOO O100 0100 0100 0100 0 100 WMUSTARD O lOO O100 4 0 50 50 5 0

5~

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

Compound I(a)*
Postemergence Activity Rate of Applications (kg/ha) .5000 .2500 .1250 .06Z5 .0313 .01-56 Species _ K V K V K V K V K V K_ _ _ _ _ _ _ _ _ _ BARNGR O100 0100 0lOn O100 0100 380 BINDWEED O 100 0100 0100 nloo oloo 3 ~0 RTCE O100 0100 nloo oloo 190 370 *Compound I(a) is the c~mpound of Example 2, 1-(4-chloro-2-fluoro-S-propargyloxyphenyl)-3-methyl-4-clifluoro-methyl-~2-1,2,4-triazolin-5-one.
TABLE 2 (Continued) Compound A*
Postemergence Activity Rate of Application (kg/ha) .5000 .2-500 `.1250 .0625 .0313 .0156 S~ V K V K V K V K V K V K

BLUE PAN O 100 0100 0100 0 100. 0 100 0 100 TABLE 2 ~Continued) Compound A~
Postemergence Activity Rate of Applications (kg/ha) .5000.2500 .1250 ~ .0~ .0156 Species V K V ~ V ~ V K V K V K
GIANTFOX ~1~0 ~ 1~0 ~1~0 ~1~0 ~1~0 ~1~0 IVYGLORY 0100 0 100 0l00 190 190 490 JOHNGR 0100 0 100 0100 0l00 430 190 RICE 0100 0 100 0100 0100 l90 2g0 SICKLEPn 0100 0 100 0100 5 0 480 50 SIGNAL~R 0100 0 100 0100 0100 0100 0100 VELVETLE 0l00 0 100 0100 0100 290 0100 *Compound A is l-t2,4-dichloro-5-propargyloxyphenyl)-3-methyl-4-diflu.oromethyl-~2-1,2,4-triazolin-5-one.
In order to better compare herbicidal activity for the two test compounds, biological efficacy tBE) 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

2 0.75 3 0.25 4 0.12 Tables 3 and 4 below show BE values calculated from the data in Tables 1 and 2 above for the present compound I(a) and the 2-chloro analog. BE values s~9 increase with herbicidal efficacy to a maxmimum value of 100.

Compound I(a)*
Preemergence Biological Efficacy (BE) Rate of Application (kg/ha) .5~00 .250~ .lZ50-.06~5.0313 .0156 Species _ BE BE BE BE BE_ _ _ SOYBEAN100 lOO lOO 100 93 85 *Compound I(a) is the compound of Example 2, 1-(4-chloro-2-fluoro-5-propargyloxyphenyl)-3-methyl-4-difluoromethyl--1,2,4-triazolin-5-one.
Compound A*
Preemergence Biological Efficacy (BE) Rate of Application (kg/ha) .
.5000 .2500 .1250.0625.0313 .0156 SpeciesBE BE BE BE BE BE

- ~L2~5~39 TABLE 3 (Continued) Compound A*
Preemergc~ 7T~7~fficacy (BE~
Rate of Application (kg/ha) .5000.2500.1250.06Z5.0313.-0IS-6 BE BE BE BE BE BE

SIC~LEPD 98 25 12 12 12 12 *Compound A is 1-(2,4-dichl~ro-5-propargyloxyphenyl)-3-methyl-4-difluoromethyl-~ -1,2,4-triazolin-5-on~.

Compound I(a)~
Postemergence Biological Efficacr Rate of Application (kg/ha) .5000.ZSOO.1~5~.U6~5.~313-.0156 Species BE BE BE BE BE BE
__ _ _ _ BARNGR 100100100 . 100 100 85 WHEAT 100100 100 93 38 n ~2~5~9 TABLE 4 (Continued) Compound I(a)*
ostemergence_Biological Efficacy Rate of Application ~k~/ha) .5000.250~.1250.0625 .0313 .-0156 Species _ BE BE BE BE BE_ _ _ _ WMUSTAR~100 100 100 100 78 0 *Compound I(a~ is the co~pound of Example 2, 1-(4-chloro-2-fluoro-5-propargyloxyphenyl)-3-methyl-4-difluoromethyl--1,2,4-triazolin-5-one.

Compound A*
Postemergence Biolo~ical Efficacy Rate of ADDlication (hQ/ka) .5000.--2500.1250.0625 .0313 .0156 Species BE BE BE BE BE BE

COCKLEBR75 25 lZ 25 0 0 JOHNGR 100 100 100 lOD 38 100 VELVETLF100 100 100 100 98 .100 *Compound A is 1-(2,4-dichloro-5-propargyloxyphenyl)-3-methyl-4-difluoromethyl-~2-1,2,4-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 ~;~46S~3~

grasses and weed broadleaves. The BE values for grasses represent the average of the BE values in Table 3 (preemergence) or Table q ~postemergence) for barnyardgrass, blue panicum, giant foxtail, green 5 ~oxtail, 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 10 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, 15 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 oE 96 while the present compound gave a BE of 99 at one-fourth the application rate, 0.125 20 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.

Average Biolo~ical Efficacy Preemergence Rate of Application (k~/ha) 0.50 0.25 0.125 0.0625 0.0313 0.0156 30 Cpd- Species BE BE BE BE PE BE
I~a)* Grasses 100 100 100 100 lO0 95 Broadleaves lO0 99 99 81 59 32 A* Grasses 100 ioo loo loo loo 99 Broadleaves 99 87 68 45 25 l8 s~

TABLE 5 (Continued) Postemergence Rate of Application (kg/ha) 0.50 0.25 0.125 0.0625 0.0313 0.0156 5 Cpd. Species BE BE BE BE BE BE
l~a)* Grasses lO0 lO0 lO0 100 91 93 Broadleaves 100 99 99 87 75 fi3 A* Grasses lO0 100 100 98 88 96 Broadleaves 96 81 73 56 56 56 *Compound I ( a) is the compound of Example 2, 1-(4-chloro-2-fluoro-~-propargyloxyphenyl)-3-methyl-4-difluoromethyl-~-1,2,4-triaæolin-5-one, and Compound A is the corresponding 1-(2,4-dichloro-5-propargyl- oxyphenyl) 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 "~esearch 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:

651~

Rating Description Percent of Main Crop Weed Control Categories Description Description 0 No effect No crop reduction No weed control or injury . _ .. . . . _ . _ . _ _ _ Slight discoloration Very poor weed or stunting control 20 Slight Some discoloration, Poor weed effect stunting or stand control Crop injury more Poor to defi-pronounced but not cient weed lasting control Moderate injury, Deficient weed crop usually control recovers 50 Moderate Crop injury more Deficient to effect lasting, recovery moderate weed control Lasting crop Moderate weed injury no recovery control Heavy injury and Control somewhat stand loss less than satis-factory Severe Crop nearly des- Satisfactory to troyed a few good weed survivors control Only occasional Very good to live plants left excellent control _ _ .
100 Complete Complete crop Complete weed effect destruction destruction 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 kilog-rams per hectare and "% C" is percent control.

~4~S !393 Table 6 ~ ~c-e~e~ Ac~
Compound Number* 3 4 S 6 7 Rate (kg/ha) 1.0 0.25 1.0 0.5 0.5 Species % C % C % C
Cotton 50 70 100 20 90 Soybean 100 100 100 90 100 Field Corn 100 100 100 100 100 Rice 100 100 90 100 100 Wheat 100 100 100 100 100 Field Bindweed 100 100 100 100 100 Morningglory 100 100 100 100 100 Velvetleaf 100 100 100 100 100 Barnyar~grass 100 100 100 100 100 Green Foxtail 100 100 100 100 100 Johnsongrass 100 100 100 100 100 Yellow Nutsedge 100 40 100 80 90 *The compound number is the number of the Example in which the particular compound was prepared.
Table 7 Postemergence Activity Compound Number* 3 4 5 6 7 Rate (kg/ha) 1.0 0.25 1.0 0.5 0.5 S~ecies ~-~ % C % C ~
Cotton 100 100 100 100 100 Soybean 100 90 100 90 80 Field Corn 70 90 100 30 80 Rice 90 100 100 30 100 Wheat 60 100 100 30 90 Field Bindweed 100 100 100 100 100 Morningglory 100 100 100 100 100 Velvetleaf 100 100 100 100 100 Barnyardgrass 100 100 100 100 100 Green Foxtail 100 100 100 100 100 Johnsongrass 100 90 100 80 90 Yellow Nutsedge 100 50 100 40 90 *The compound number is the number of the Example in which the particular compound was prepared.
For herbicidal application, the active compounds as ~bove defined are formulated into herbicidal compositions by admixture in herbicidally effective a~ounts 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 o~ 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 ac~ as dispersants and carriers ~or 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 co~pound and 99.0 parts of talc.

658~3 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 5 ultimately applied to the soil either as a dry dust or as an emulsion in water or other liquid. Typical carriers for wettable powders inc]ude Fuller's earth, kaolin clays, silicas, and other highly absorbent, readily wet inorganic dilutents. Wettable powders 10 normally are prepared to contain about 5-80~ o~ 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 15 formulation contains ~0.8 parts of the herbicidal compound, 17~9 parts of Palmetto clay, and 1.0 part of sodium lignosulEonate and 0.3 part of sul~onated aliphatic polyester as ~etting agents. Frequently, additional wetting agent and/or oil ~ill be added to 20 the tank-mix for post-emergence application to acilitate dispersion on the foliage and absorption by the plant.
Other useful formulations for herbicidal applica-tions are emulsifiable concentrates. ~mulsifiable 25 concentrates are homogeneous liquid or paste composi-tions 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 30 naphthas, isophorone, or other non-volatile organic solvent. For h0rbicidal application these concentrates are dispersed in water or other li~uid carrier, and normally applied as a spray to the area to be treated. The percentage by weight of the 35 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 emulsifyin~ agents used in agricultural formulations include, for 5 example, the alkyl and alkylaryl sulfonates and sulates 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 10 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 Aesired concentration, such as acetone, 15 alkylated naphthalenes, xylene or other organic sol-vents. 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, 20 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 25 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 dispersib~e granular formulations described in U.S. patent No. 3,920,442, 30 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, 35 ertilizers, or other agricultural chemicals and may be used as effective soil sterilants as well as .~2~6589 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 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); benzothiadia-zinone herbicides such as 3-(1-methylethyl)-tlH)-2,1, 3-henzothiadiazin-~-(3H)-one-2,2-dioxide (bentazon);
triazine herbicides such as 6-chloro-N-ethyl-N-(l-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); dinitrol-aniline herbicides such as 2s6-dinitro-N,N-dipropyl-4-(trifluoromethyl)benzeneamine (trifluralin); and aryl urea herbicides such as N'-(3,4-di-chlorophenyl)-N, N-dimethylurea (diuron) anA N,N-dimethyl-N'-[3-(tri-fluoromethyl)phenyl]urea (fluometuron).
In general, the compounds of this invention havingthe formula F O
Cl ~ -CN32 in which R is a radical selected from 2-propynyl, l-methylethyl, 1-methyl-2-propynyl, methoxymethyl, 2-propenyl, and 1-methyl-2-methoxyethyl, may be ~2~5~

prepared by (a) reacting the compound of the formula Cl~[~-CHF2 N

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 F O

Cl ~J'~N-H

in which P~ is as defined above, with CHF2-X, in which X is a good leaving group, in the presence o 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 25 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 30 is bromide or chloride.

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A compound of the formula in which R is a radical selected from methyl, 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 methyl, 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.