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Halophenoxy benzamide herbicides |
| RE32550 |
Halophenoxy benzamide herbicides
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| Patent Drawings: | |
| Inventor: |
Theissen |
| Date Issued: |
November 24, 1987 |
| Application: |
06/075,367 |
| Filed: |
September 14, 1979 |
| Inventors: |
Theissen; Robert J. (Westfield, NJ)
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| Assignee: |
Rhone-Poulenc Agrochimie (Lyons, FR) |
| Primary Examiner: |
Demers; Arthur P. |
| Assistant Examiner: |
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| Attorney Or Agent: |
Morgan & Finnegan |
| U.S. Class: |
504/337; 564/166 |
| Field Of Search: |
260/559R; 71/118; 564/166 |
| International Class: |
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| U.S Patent Documents: |
3013054; 3475427 |
| Foreign Patent Documents: |
2019821; 1502538 |
| Other References: |
Deshpande et al, Chemical Abstracts, 53 (1959), column 14,100.. |
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| Abstract: |
2-Nitro-5-(halophenoxy)benzoic acids and esters, salts, amides, and acyl halides thereof comprise a class of compounds that are highly effective pre- and post-emergence herbicides. |
| Claim: |
What is claimed is:
1. An herbicidal compound having the formula: ##STR2## wherein X is halogen, n is 1 to 5, and R is amido, alkylamido .[.(C.sub.1 --C.sub.6).]. .Iadd.(C.sub.1--C.sub.3).Iaddend., or dialkylamido .[.(C.sub.1 --C.sub.6).]. .Iadd.(C.sub.2 --C.sub.6).Iaddend.wherein each alkyl of the dialkylamido contains 1 to 3 carbon atoms. .[.
2. A compound of claim 1, wherein said compound is N-methyl 2-nitro-5-(2',4'-dichlorophenoxy)benzamide..]. .[.3. A compound of claim 1, wherein said compound is N,N-dimethyl
2-nitro-5-(2',4'-dichlorophenoxy)benzamide..]. 4. A compound of claim 1, wherein said compound is N,N-dimethyl 2-nitro-5-(2',4',6'-trichlorophenoxy)benzamide. .[.5. A compound of claim 1, wherein said compound is N,N-dimethyl2-nitro-5-(2',4'-dichloro-6'-fluorophenoxy)benzamide..]. .[.6. A compound of claim 1, wherein said compound is N-sec-butyl
2-nitro-5-(2',4'-dichloro-6'-fluorophenoxy)benzamide..]. 7. A compound of claim 1, wherein said compound is 2-nitro-5-(2',4',6'-trichlorophenoxy)benzamide. |
| Description: |
BACKGROUND OF THEINVENTION
Field of the Invention
This invention is concerned with certain phenoxybenzoic acid compounds and their use as herbicides.
DESCRIPTION OF THE PRIOR ART
It has been proposed to use as herbicides 2-methoxybenzoic acids (U.S. 3,013,054) and 4-phenoxybenzoic acids (French 1,502,538). It is the discovery of this invention, however, that benzoic acids having a phenoxy substituent in the 5-positionare very effective herbicides.
SUMMARY OF THE INVENTION
This invention provides herbicidal compound having the formula: ##STR1## wherein X is halogen, n is 1 to 5, and R is amido, alkylamido (C.sub.1 --C.sub.6) preferably C.sub.1 --C.sub.4, or dialkylamido (C.sub.1 --C.sub.6) preferably C.sub.1--C.sub.4.
DESCRIPTION OF SPECIFIC EMBODIMENTS
The compounds of this invention are readily prepared by the Ullmann ether synthesis reaction between the alkali metal (Na, K) salt of a halophenol and a 5-halo (Cl, Br)-2-nitrobenzoic acid or an ester, amide, or salt thereof. The5-halo-2-nitrobenzoic acid is readily prepared by nitrating a m-halotoluene, followed by oxidation of the methyl group by well-known procedures.
Non-limiting examples of the compounds of this invention are:
2-nitro-5-(2',4',6'-trichlorophenoxy)benzoic acid;
methyl 2-nitro-5-(2',4',6'-trichlorophenoxy)benzoate;
propyl 2-nitro-5-(2',4',6'-tribromophenoxy)benzoate;
phenyl 2-nitro-5-(2',4',5'-trifluorophenoxy)benzoate;
2-nitro-5-(2',4',6'-triiodophenoxy)benzoic acid;
2-nitro-5-(2',4',6'-trichlorophenoxy)benzoyl chloride;
2-nitro-5-(2',4',6'-trichlorophenoxy)benzamide;
N-ethyl 2-nitro-5-(2',4',6'-trichlorophenoxy)benzamide;
N-isopropyl 2-nitro-5-(2',4',6'-trichlorphenoxy)benzamide;
N,N-dimethyl 2-nitro-5-(2',4',6'-trichlorophenoxy)benzamide;
sodium (or potassium) 2-nitro-5-(2',4',6'-trichlorophenoxy)benzoate;
ethylammonium 2-nitro-5-(2',4',6'-trichlorophenoxy)benzoate;
ethanolammonium 2-nitro-5-(2',4',6'-trichlorophenoxy)benzoate;
sodium 2-nitro-5-(2',4',6'-trichlorophenoxy)benzoate;
methyl 2-nitro-5-(2',4',5'-trichlorophenoxy)benzoate;
methyl 2-nitro-5-(2',4'-dichlorophenoxy)benzoate; and
methyl 2-nitro-5-(2',3',4',5',6'-pentachlorophenoxy)benzoate.
The following example illustrates the preparation of a typical compound of this invention and demonstrates a method for product recovery.
EXAMPLE 1
Methyl 2-nitro-5-(2',4',6'-trichlorophenoxy)benzoate
A stirred solution of methyl 5-chloro-2-nitro-benzoate (17.0 g., 0.079 mole) and the potassium salt of 2,4,6-trichlorophenol (18.6 g., 0.079 mole) in dimethyl sulfoxide (100 ml.) was heated at 90.degree. for 17 hours. The cooled reactionmixture was diluted with water (500 ml.) and then extracted with ether (3.times.100 ml.). The combined ether fractions were washed with 10% sodium hydroxide solution (2.times.30 ml.) and then with a saturated aqueous sodium chloride solution. The ethersolution was dried (Na.sub.2 SO.sub.4) and the solvent evaporated to give a dark oil. Two crystallizations (petroleum ether) gave 1.91 g. of a pale yellow solid, m.p. 101.degree.-103.degree..
EXAMPLE 1
I.R. (Nujol): c.dbd.o 1723, c.dbd.o 1240, and 1260 cm..sup.-1
NMR (CDCl.sub.3): methyl 3.91 p.p.m. (3H), quartet
6.96 p.p.m. (1H, J=2.5 and 8 c.p.s.), doublet
7.05 p.p.m. (1H, J=2.5 c.p.s.), broad singlet
7.05 p.p.m. (2H), and doublet 8.01 p.p.m. (1H, J=8 c.p.s.).
EXAMPLES 2 through 13
The ester of Example 1 was hydrolyzed to the corresponding acid and using known procedures for the preparation of amides, twelve other compounds within the scope of this invention were prepared. These compounds are:
(2) 2-nitro-5-(2',4'-dichlorophenoxy)benzamide.
(3) N-methyl 2-nitro-5-(2',4'-dichlorophenoxy)benzamide.
(4) N,N-dimethyl 2-nitro-5-(2',4'-dichlorophenoxy)benzamide.
(5) N-propyl 2-nitro-5-(2',4'-dichlorophenoxy)benzamide.
(6) 2-nitro-5-(2',4',6'-trichlorophenoxy)benzamide.
(7) N-methyl 2-nitro-5-(2',4',6'-trichlorphenoxy)benzamide.
(8) N,N-dimethyl 2-nitro-5-(2',4',6'-trichlorophenoxy)benzamide.
(9) N-propyl 2-nitro-5-(2',4',6'-trichlorphenoxy)benzamide.
(10) N-isopropyl 2-nitro-5-(2',4',6'-trichlorphenoxy)benzamide.
(11) N,N-diethyl 2-nitro-5-(2',4',6'-trichlorophenoxy)benzamide.
(12) N,N-dimethyl 2-nitro-5-(2',4'-dichloro-6'-fluorophenoxy)benzamide.
(13) N-secbutyl 2-nitro-5-(2',4'-dichloro-6'-fluorophenoxy)benzamide.
For comparison, the following position isomer of Example 4 was prepared, the acid of which is disclosed in U.S. 3,475,427.
(14) N,N-dimethyl-2-nitro-3-(2',4'-dichlorophenoxy)benzamide.
The compounds of the invention can be applied in various ways to achieve herbicidal action. They can be applied, per se, as solids or in vaporized form, but are preferably applied as the toxic components in pesticidal compositions of thecompound and a carrier. The compositions can be applied, as dusts; as liquid sprays, or as gas-propelled sprays and can contain, in addition to a carrier, additives such as emulsifying agents, binding agents, gases compressed to the liquid state,odorants, stabilizers, and the like. A wide variety of liquid and solid carriers can be used. Non-limiting examples of solid carriers include talc, bentonite, diatomaceous earth, pyrophyllite, fullers earth, gypsum, flours derived from cotton seeds andnut shells, and various natural and synthetic clays having a pH not exceeding about 9.5. Non-limiting examples of liquid carriers, include water; organic solvents, such as alcohols, ketones, amides and esters; mineral oils, such as kerosene, light oils,and medium oils and vegetable oils, such as cottonseed oil.
In practice, herbicidal application is measured in terms of pounds of herbicide applied per acre. The compounds of this invention are effective herbicides when applied in herbicidal amounts, i.e., at rates between about 0.2 pounds and about 10pounds per acre.
HERBICIDAL EFFECTIVENESS
Method of Propagating Test Species
Crabgrass Digitaria sanguinalis
Yellow Foxtail grass Seteria glauca
Johnson grass Sorgum Halepense
Barnyard grass Echinochloa crus-galli
Amaranth pigweed Amaranthus retroflexus
Turnip Brassica sp.
Cotton Gossypium hirsutum var. DPL smooth leaf
Corn Zea Mays var. Golden Bantam
Bean Phaseolus vulgaris var. Black Valentine
All crop and weed species are planted individually in 3" plastic pots containing potting soil. Four seeds of each of corn, cotton, and snapbeans are seeded to a depth equal to the diameter of the seed. All other species are surface seeded andsprinkled with screened soil in an amount sufficient to cover the seeds. Immediately after planting, all pots are watered by sub-irrigation in greenhouse trays. Pots for the pre-emergence phase are seeded one day before treatment.
Planting dates for the post-emergence phase are varied so that all the seedlings will reach the desired stage of development simultaneously. The proper stage of seedling development for treatment in the post-emergence phase is as follows:
Grasses: 2 inches in height
Pigweed & Turnips: 1 or 2 true leaves visible above cotyledons.
Cotton: first true leaf 1 inch in length; expanded cotyledons.
Corn: 3 inches-4 inches in height.
Beans: primary leaves expanded, growing point at primary leaf node.
Method of Treatment
Spray applications are made in a hood containing a movable belt and fixed spray nozzle. For passage through the spray hood, one pot of each species (pre-emergence phase) is placed on the forward half of a wooden flat and one pot of establishedplants (post-emergence phase) is placed on the rear half of the flat. Treatments are moved to the greenhouse after spraying. Watering during the observation period is applied only by sub-irrigation.
Compounds are screened initially at a rate of application equivalent to four to eight pounds per acre. Two weeks after treatment the pre- and post-emergence percent injury is visually rated. Subsequent testing was carried out at 2.1 and 0.5pounds per acre.
Herbicidal testing of the compounds of Examples 2 through 13 and of the comparative compound showed the results set forth in Table I. The plants are tablulated using the following abbreviations:
TABLE I __________________________________________________________________________ PRE-POST-EMERGENCE Compound Dosage, Example No. lbs./acre CG JG BG PW TP CT CN BN __________________________________________________________________________ 2 4 80/70 40/40 40/30 100/100 20/70 100/40 0/20 100/100 3 8 80/90 60/80 70/40 --/-- 90/100 30/80 0/30 0/100 4 8 90/90 40/30 20/30 --/-- 90/100 30/50 40/0 80/100 4 4 30/40 20/20 0/20 --/-- 20/80 80/50 0/20 0/90 5 8 80/90 30/40 20/40 --/-- 0/100 80/50 40/0 0/100 6 8 0/50 20/30 20/30 0/100 70/100 70/70 0/30 50/100 6 4 --/-- --/-- --/-- 0/100 0/80 --/-- --/-- --/-- 6 2 --/-- --/----/-- 0/80 0/90 --/-- --/-- --/-- 7 8 80/70 0/20 50/40 --/-- 20/100 100/20 0/20 0/100 7 4 --/-- --/-- --/-- --/-- --/70 --/-- --/-- --/-- 8 8 70/60 20/30 40/30 --/100 80/100 50/70 0/30 50/100 9 8 30/60 0/20 0/20 --/-- 0/90 30/30 0/0 0/100 9 4 --/-- --/-- --/-- --/-- 0/30 --/-- --/-- --/-- 10 8 40/50 0/20 20/30 --/-- 70/80 50/0 0/70 0/90 11 8 30/40 0/-- --/-- --/-- 20/100 --/30 --/-- 0/50 12 8 100/0 20/-- 60/-- --/-- 100/80 100/50 70/-- --/-- 12 4 0/-- 0/-- 0/-- --/-- 100/-- 100/-- 70/-- --/-- 12 2 70/-- 40/-- 30/-- --/-- 60/-- 30/20 20/-- --/-- 13 8 90/0 0/-- 0/-- --/-- 100/90 100/100 80/-- --/-- 13 4 80/-- 0/-- 0/-- --/-- 90/-- 100/-- 40/-- --/-- 13 2 30/-- 0/-- 0/-- --/-- 80/-- 30/-- 80/-- --/-- 14 8 40/0 0/-- 0/-- .sup. 20/.sup.1 -- 20/20 0/0 0/-- 0/0 __________________________________________________________________________ .sup.1 Bindweed. Crabgrass CG Johnson grass JG Barnyard grass BG Bean BN Pigweed PW Turnip TP Cotton CT Corn CN
Although the present invention has been described with preferred embodiments, it is to be understood that modifications and variations may be resorted to, without departing from the spirit and scope of this invention, as those skilled in the artwill readily understand. Such modifications and variations are considered to be within the purview and scope of the appended claims.
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