GB1570997A

GB1570997A - N - sulphonyl thiolcarbamates and the use thereof as herbicide antidotes

Info

Publication number: GB1570997A
Application number: GB40796/76A
Authority: GB
Original assignee: Stauffer Chemical Co
Current assignee: Stauffer Chemical Co
Priority date: 1975-10-02
Filing date: 1976-10-01
Publication date: 1980-07-09
Also published as: JPS5248641A; BG27718A3; DE2644446A1; NL7610907A; BR7606585A; RO72431A; CA1103694A; DE2644446C2; CH628210A5; MX4831E; AR222442A1; ES452487A1; FR2326418A1; AU504263B2; AU1832776A; DK442376A; NZ182205A; JPS6014021B2; TR18954A; IL50604A

Abstract

The herbicidal preparation contains a thiocarbamate as herbidical active substance and a compound of the formula I in such an amount that it acts as an antidote. The substituents in the formula I have the meaning given in Patent Claim 1. The compounds of the formula I are particularly suitable for protecting soya bean crops and other agricultural products when thiocarbamate herbicides are used. <IMAGE>

Description

(54) N-SULPHONYL THIOLCARBAMATES AND THE USE THEREOF AS HERBICIDE ANTIDOTES (71) We, STAUFFER CHEMICAL COMPANY, a Corporation organised under the laws of the State of Delaware, United States of America, of Westport, Connecticut 06880, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to N-sulphonyl thiolcarbamates and the use thereof as herbicide antidotes.

While many herbicides are immediately toxic to a large number of weed pests, it is known that the effect of many herbicides upon important plant cultivations is either non-selective or not adequately selective. Thus, many herbicides damage not only the weeds to be controlled, but, to a greater or lesser extent, the desirable cultivated plants as well. This holds true for many herbicidal compounds which have been commercially successful and are commercially available. These herbicides include various types, such as triazines, urea derivatives, halogenated acetanilides, carbamates and thiolcarbamates. Some examples of these compounds are described in U.S. Patent Nos. 2,913,327; 3,037,853; 3,175,897; 3,185,720; 3,198,786; and 3,582,314.

The side effect of injury to a cultivated crop by various herbicides is particularly inconvenient and unfortunate. When used in the recommended amounts in the soil to control broadleaf weeds and grasses, serous malformation or stunting of the crop plants sometimes result. This abnormal growth in the crop plants results in loss of crop yield. The search continues for good selective herbicides.

Previous attempts have been described to overcome this problem. The treatment of the crop seed with certain "hormonal" antagonistic agents prior to planting has been described; see U.S. Patent Nos. 3,131,509 and 3,564,768. The protective agents, as well as the herbicides, in these prior references are largely specific to certain cultivated plant species or in the nature of the antagonistic agents. The prior antagonistic agents have not been notably successful. The aforementioned references specifically exemplify and describe the treatment of seeds employing compounds of a different chemical class, not suggestive of the present invention.

The literature describes the preparation of certain N-(benzenesulphonyl) thiolcarbamates for which no utility is disclosed. The reference, Hirooka et al., Nippon Kagaku Zasshi: 1970, 91(3) 270(5), CA 73:14369w (1970), relates to the synthesis and reactions of bis - [N - (phenylsulphonyl) - formimidoyl]disulphides.

From certain reactions of an appropriate disulphide with hydrogen peroxide, there is obtained N-(phenylsulphonyl)methyl thiolcarbamates. Furthermore, there is reference to certain alkyl p-toluenesulphonylthiolcarbamates used in pharmacological evaluations. These latter compounds are by Kriesel, D.C. et al., J.

Pharm Sic!., 1968, 57(10), 1791-3.

It has now been discovered that cultivated crop plants may be protected against injury by thiolcarbamate-type herbicides, alone or in mixtures or combination with other compounds. Furthermore, as an alternative effect, the tolerance of growing plants, more particularly soybeans, to the thiolcarbamate herbicides, more particularly S - n - propyl N,N - di - n - propylthiolcarbamate, may be increased substantially by adding to the soil an N-(substituted and unsubstituted benzenesulphonyl) thiolcarbamate which is an effective antidote with the said thiolcarbamate herbicide.

In a first embodiment, the present invention provides a composition comprising a thiolcarbamate herbicide and an antidotally effective amount of a compound corresponding to the following general formula:

wherein X represents methyl, chloro, bromo or methoxy; n represents 0, 1, 2 or 3; R, represents hydrogen or methyl; and R2 R, represents C1-C4 alkyl, benzyl, 4-chlorophenyl or methylenethio-p- chlorobenzene sulphonyl carbamate; provided that when n represents 0 and R, represents methyl, then R2 represents other than ethyl.

In a second embodiment, the present invention provides a composition comprising a thiolcarbamate herbicide and an antidotally effective amount of a compound corresponding to the following general formula:

wherein X represents hydrogen, methyl, chloro, bromo, or methoxy; R, represents hydrogen or methyl; and R2 represents C1-C4 alkyl, benzyl, or 4-chlorophenyl; provided that when X represents hydrogen and R, represents methyl, then R2 represents other than ethyl.

In a third embodiment, the present invention provides a composition comprising S - n - propyl - di - n - propylthiolcarbamate and an antidotally effective amount of a compound corresponding to the following general formula:

wherein X represents hydrogen, methyl, chloro, bromo or methoxy; R, represents hydrogen or methyl, and R2 represents C1-C4 alkyl, benzyl or 4-chiorophenyl; provided that when X represents hydrogen and R, represents methyl, then R2 represents other than ethyl.

In the first embodiment of the present invention, it is preferred that the composition should comprise a compound corresponding to the above-defined general formula: wherein Xn represents 2,4,6-methyl; R, represents hydrogen; and R2 represents alkyl.

In the third embodiment of the present invention, it is preferred that the composition should comprise a compound corresponding to the above-defined general formula: wherein X represents methyl; R, represents hydrogen; and R2 represents alkyl; wherein X represents hydrogen; Rl represents hydrogen; and R2 represents alkyl; wherein X represents chloro; R1 represents methyl; and R2 represents alkyl; wherein X represents chloro; R, represents hydrogen; and R2 represents alkyl; wherein X represents methoxy; R, represents hydrogen; and R2 represents alkyl; wherein X represents bromo; R, represents hydrogen; and R2 represents alkyl.

The present invention also provides a method of controlling vegetation which comprises applying to the locus where the said control is desired such a composition.

The present invention also provides a method of protecting a plant crop, in particular soybeans, from injury due to a thiolcarbamate herbicide, in particular S - n - propyl - di - n - propylthiolcarbamate, which comprises applying to the soil in which the crop is to be planted, prior to planting, a non-phytotoxic antidotally effective amount of a compound corresponding to one of the above defined general formulae.

The present invention also provides a method of protecting a plant crop from injury due to a thiolcarbamate herbicide, in particular S - n - propyl - di - n propylthiolcarbamate, which comprises applying to the plant seed, prior to planting a non-phytotoxic antidotally effective amount of a compound corresponding to one of the above defined general formulae.

The present invention also provides a crop seed, in particular a soybean having applied thereto a compound corresponding to one of the above-defined general formulae.

Certain of the compounds used according to the present invention are considered to be novel compounds.

The present invention provides a compound corresponding to the following general formula:

wherein X represents methyl, chloro, bromo or methoxy; n represents 0, 1, 2 or 3; R, represents hydrogen or methyl; and R2 represents C2-C4 alkyl, benzyl, 4-chlorophenyl or methylenethio - p chlorobenzene sulphonyl carbamate; provided that when X represents methyl then R2 represents other than alkyl; and, when n represents 0 and R, represents methyl, then R2 represents other than ethyl.

A preferred compound corresponding to the above-defined general formula in that wherein Xn represents 2,4,6-methyl; R, represents hydrogen; and R2 represents alkyl.

The present invention also provides a compound corresponding to the following general formula:

wherein X represents hydrogen, methyl, chloro, bromo or methoxy; R, represents hydrogen or methyl; and R2 represents C2-C4 alkyl, benzyl or 4-chlorophenyl; provided that when X represents methyl, then R2 represents other than alkyl, and when X represents hydrogen and R1 represents methyl then R2 represents other than ethyl.

Certain preferred compounds corresponding to the above-defined general formula are those: wherein X represents hydrogen; R, represents hydrogen; and R2 represents alkyl; wherein X represents chloro; R, represents methyl; and R2 represents alkyl; wherein X represents chloro; R, represents hydrogen; and R2 represents alkyl; wherein X represents methoxy; R, represents hydrogen; and R2 represents alkyl; wherein X represents bromo; R, represents hydrogen; and R2 represents alkyl.

The present invention further relates to a process for the preparation of such compounds.

In the above descriptions the following embodiment is intended for the various alkyl substituent groups. As exemplary of the alkyl portion within the preferred embodiment are the following: methyi, ethyl, n-propyl, isopropyl, n-butyl, sec- butyl, isobutyl, and tert.-butyl. Whereas n may be zero or an integer of from 1 to 3 preferably n represents 3 when represents methyl; and n is a para-substitution of the X moiety.

As an alternative mode of action, the compounds used according to the present invention may interfere with the normal herbicidal action of the thiolcarbamate-type and other herbicides to render them selective in the action thereof. Whichever mode of action is present, the corresponding beneficial and desirable effect is the continued herbicidal effect of the thiolcarbamate with the accompanying decreased herbicidal effect on desired crop species.

Therefore, the terms "herbicidal antidote" or "antidotal amount" is meant to describe that effect which tends to counteract the normal injurious herbicidal response that the herbicide might otherwise produce. Whether it is to be termed for example, a remedy, interferant or protectant will depend upon the exact mode of action. The mode of action is varied, but the effect which is desirable, is the result of the method of treating the soil in which a crop is planted. Hitherto, there have been no systems which have been satisfactory for this purpose.

The compounds used according to the present invention corresponding to the above-defined general formulae may be prepared by several different procedures depending upon the starting materials.

The appropriate intermediate, arylsulphonamide, was reacted with an appropriate chlorothiolformate in the presence of a hydrogen chloride acceptor to prepare the desired compound. Work-up and purification procedures involved conventional methods of extraction, distillation or crystallization. In most instances, characterization of the structure was by infrared spectroscopy, nuclear magnetic resonance spectroscopy or mass spectrometry, as well as physical constants.

The compounds used according to the present invention and the preparation thereof are more particularly illustrated by the following Examples. Following the Examples is a Table of compounds which are prepared according to the procedures described herein. Compound numbers have been assigned to them and are used for identification throughout the balance of the specification.

EXAMPLE I Preparation of N - (p - methoxybenzenesulphonyl) - ethyl Thiolcarbamate p-methoxybenzenesulphonamide (11.7 g, 0.64 mole), potassium carbonate (21.5 g., 0.156 mole) and ethyl chlorothiolformate (8.5 g., 0.068 mole) were refluxed in 80 ml. of acetone for eight hours. The cooled mixture was poured into 350 ml.

water and the solution filtered through "Celite" (Registered Trade Mark) and extracted with benzene to remove any unreacted chlorothiolformate. It was then acidified with hydrochloric acid (pH about 2) with cooling. The mixture was extracted with benzene and the extract washed with water and dried over magnesium sulphate. Removal of the solvent left the product as a very viscous oil.

There was obtained 8.4 g. (48% of the theoretical yield) of the title compound, n030 1.5502.

EXAMPLE II Preparation of N - (p - chlorobenzenesulphonyl) - ethyl Thiolcarbamate p-chlorobenzenesulphonamide (12.0 g., 0.063 mole), potassium carbonate (21.5 g., 0.156 mole) and ethyl chlorothiolformate (8.5 g., 0.068 mole) were refluxed in 75 ml. of acetone for six hours. The work-up was as in Example I. The crude product was triturated with hexane and dried. There was obtained 12.4 g. (70% of the theoretical yield) of the title compound, m.p. 93--950C. The structure was confirmed by infrared and nuclear magnetic resonance spectroscopy and mass spectrometry.

EXAMPLE III Preparation of N - (benzenesulphonyl) - ethyl Thiolcarbamate Benzenesulphonamide (39.3 g., 0.25 mole) and potassium carbonate (90 g., 0.65 mole) were placed in 300 ml. of acetone and ethyl chlorothiolformate (41 g., 0.33 mole) added over several hours. The mixture was stirred for one hour at room temperature, then refluxed for 12 hours. It was cooled, poured into one litre of water and acidified with 100 ml. hydrochloric acid. The product was extracted with 250 ml. benzene and the extract dried over magnesium sulphate. It was filtered and the solvent removed. Pentane (100 ml.) was added, whereupon the product crystallized.It was filtered, washed with 50 ml. pentane and dried at 500 C. There was obtained 58 g. (95 /n of the theoretical yield) of the title compound, m.p. 100- 103"C. Analysis: N; calculated, 5.72; observed, 5.59; Analysis: S; calculated 26.1; observed, 26.24.

EXAMPLE IV Preparation of N - (p - chlorobenzenesulphonyl) - p - chlorophenyl Thiolcarbamate p-chlorobenzenesulphonamide (19.1 g., 0.1 mole), potassium carbonate (30 g., 0.22 mole) and p-chlorophenyl chlorothiolformate (22 g., 0.11 mole) in 150 ml.

acetone were refluxed and stirred for 10.5 hours. The cooled mixture was poured into one litre of water and acidified with acetic acid. The precipitate was filtered, washed with water and dried. There was obtained 20 g. (55.5% of the theoretical yield) of the title compound, m.p. 129--1320C. Analysis: N; calculated, 3.85; observed, 4.83; S; calculated, 17.67; observed, 17.37.

TABLE I

Compound m.p. "C.

Number n x R1 R2 or n30 1 1 para-CH3 H C2H5 104--110 2 0 H C2H5 100103 3 1 para-C1 H 4-Cl-s 129-132 4 1 para-CI CH3 C2H5 1.5643 5 1 para-CI H C2H5 9395 6 1 para-Br H C2H5 102-107 7 1 para-CI H n-C3H7 9496 8 1 para-C1 H t-C3H7 77-83 9 1 para-OCH3 H C2H5 1.5502 10 1 para-C1 H CH20 996 11 3 2,4,6-CH3 H C2Hs 105-108 12 1 para-CI H CH2SC(O)NHS(O2)-4-Cl 238-239 dec.

The herbicides indicated in the Tables and elsewhere are used at rates which produce effective control of undesirable vegetation. The range of rates employed herein produce representative results within the recommended amounts set forth by the supplier. Therefore, the weed control in each instance is commercially acceptable within the desired or recommended amount.

It is clear that the class of herbicidal agents described and illustrated herein is characterized as an effective herbicide exhibiting such activity. The degree of this herbicidal activity varies among specific compounds and among combinations of specific compounds within the class. Similarly, the degree of activity to some extent varies among the species of plants to which a specific herbicidal compound or combination may be applied. Thus, selection of a specific herbicidal compound or combination to control undesirable plant species readily may be made. Within the present invention, the prevention of injury to a desired crop species in the presence of a specific compound or combination may be achieved. The beneficial plant species which may be protected by this method is not intended to be iimited by the specific crops mentioned below.

The herbicidal compounds employed in the utility of the present invention are active herbicides of a general type. That is, the members of the classes are herbicidally effective against a wide range of plant species with no discrimination between desirable and undesirable species. The method of controlling vegetation comprises applying a herbicidally effective amount of the herein described herbicidal compounds to the area or plant locus where control is desired. The present compositions include those wherein the active thiolcarbamate herbicidal compound is preferably S-n-propyl N,N-di-n-propyl thiolcarbamate.

A "herbicide" as used herein means a compound which controls or modifies the growth of vegetation or plants. Such controlling or modifying effects include all deviations from natural development; for example, killing, retardation, defoliation, desiccation, regulation, stunting, tillering, stimulation and dwarfing. By "plants", it is meant germinant seeds, emerging seedlings and established vegetation including the roots and above-ground portions.

Evaluation Procedures Flats to be used for growing the crops and weed species were filled with loamy sand soil. Stock solutions of the herbicide and each candidate antidote were prepared as follows: A. Herbicide -- S-n-propyl N,N-di-n-propyl thiolcarbamate -- "Vernam 6E 1560 mg. of Vernam 6E was diluted in 250 ml. of water so that 5 ml applied to a flat is equivalent to 6 Ib/A per flat (based on the surface area of a flat).

B. Antidote -- of each candidate 78 mg. was dissolved in 20 ml. of acetone with 1%, by weight, Tween (Registered Trade Mark) 20 (polyoxyethylene sorbitan monolaurate) so that 5 ml. when applied by pre-plant incorporation technique (PPI) is equal to 5 Ib/A per flat.

The herbicide and antidotes were applied to the soil together as a tank mix employing a pre-plant incorporation technique. To prepare the combined tank mix, 5 ml. of the Vernam stock solution and 5 ml. of each of the antidote stock solutions were admixed, followed by incorporation into the soil from the flats during incorporation in a rotary mixer.

One row each of the following weeds and crop was seeded into the treated- soil in the flats: Watergrass (Echinochloa crusgalli); Foxtail (Sataria viridis); and Soybeans (Glycine max).

The flats were placed on greenhouse benches where temperatures were maintained at from 70 to 900 F. The soil was watered by sprinkling to ensure good plant growth. Injury ratings were taken 2 and 4 weeks after the application was made. Individual flats treated with the herbicide alone were included to provide a basis for determining the amount of injury reduction provided by the herbicide antidotes.

The following Table includes results as percent protection for the crop according to the procedures discussed above. The percent protection is determined by a comparison with flats not treated with the candidate antidotes.

TABLE II Application Method: Pre-plant Incorporation -- PPI (Tank Mix) Crop Species: Soybeans (Glycine max) Weed Species: Foxtail (Sataria viridis) Watergrass (Echinochloa crusgalli) *=% injury **= /O protection PPI (6 Ib/A) (Tank Mix) Compound Number Soybeans Watergrass Foxtail Vernam 6 Ib/A 40* 100* 100* 1** 37.5 0 0 2 37.5 0 0 3 25 0 0 4 25 0 0 5 50 0 0 6 25 0 0 7 25 0 0 8 50 0 0 9 25 0 0 loa 75 0 0 11 33 0 0 12 50 0 0 a=Pre-plant incorporation of Vernam and antidote applied separately to soil prior to incorporation.

The thiolcarbamate herbicide S-ethyl cyclohexylethyl thiolcarbamate and compound number 6 when applied to the soil together as a tank mix employing preplant incorporation technique, exhibited 50 percent protection to grain sorghum (milo) planted in the treated soil. That is, the injury to emerging grain sorghum plants was decreased by at least 50 percent when grown in soil treated with a tank mix of compound number 6 and S-ethyl cyclohexylethyl thiolcarbamate. This is compared to grain sorghum (milo) planted in soil containing a treatment of only the thiolcarbamate herbicide.

4 Variousiowther varieties of legumes were tested for antidote activity in conjunction with a representative thiolcarbamate herbicide and a N (benzenesulphonyl) thiolcarbamate. Legumes are plants that have a symbiotic relationship with nitrogen fixing organisms. For example, soybeans, varieties of phaeolus vulgarius, peanuts, alfalfa, cloves and peas.

The antidote candidate from the above list of N-(benzenesulphonyl) thiolcarbamates compound number 5 was used at the rates of 1 and 2 Ib/A. The stock solution used consisted of 39 mg. dissolved in 25 ml. of acetone, such that 2.5 ml. is equivalent to 1 Ib/A when applied pre-plant incorporated. The representative thiolcarbamate herbicide was EPTC, S-ethyl N,N-dipropyl thiolcarbamate. The herbicide stock solution was made up by dissolving 1560 mg. of EPTC 6E in 250 ml.

water, such that 5 ml. of solution was equivalent to 6 Ib/A when pre-plant incorporated in the soil.

Navy beans and pinto beans were evaluated in this test. Also present in the planted flats were the weed species, watergrass and foxtail. The results were rated at two and four weeks after treatment and seeding. After two weeks, EPTC at 6 IblA with I Ib/A and 2 Ib/A compound number 5 present injured only 10 percent of the navy beans and 0 percent of the pinto bean plants. After four weeks, at 1 Ib/A navy bean plants were protected 23 percent and pinto bean plants were protected 40 percent. At 2 Ib/A after four weeks, navy beans were protected 23 percent and pinto beans 20 percent. The watergrass and foxtail weed species were completely (100 percent) controlled four weeks after treatment with the antidote and herbicide.

Seed Treatment Test Small flats were filled with Felton loamy sand soil. Soil incorporated herbicides were applied at this time. The soil from each flat was placed into a fivegallon cement mixer where the soil was mixed as the herbicides were applied using a predetermined amount of a stock solution containing 780 mg. of approximately 75 percent active ingredient to 125 ml. of water. 5 ml. of stock solution was applied to the soil in a volumetric pipette. 5 ml. of stock solution contained an equivalent of herbicide which equals to six pounds per acre when applied to the soil in the flats.

After the herbicide incorporation, the soil was placed back into the flats.

Flats of herbicide-treated and untreated soil were then ready to be planted. A pint sample of soil was removed from each flat and placed next to each flat for later use in covering the seeds. The soil was leveled and rows one-half inch deep were made for planting seeds. Alternating rows of treated and untreated crop seeds were sown. In each test, soybean (Glycine max) seeds were planted in each row. Rows were approximately one and one-half inches apart in the flat. Seeds were treated by preparing a stock solution by dissolving 250 mg. of the antidote compound in 2.5 ml. of acetone, then using 0.5 ml. of the stock solution to treat 10 g. of soybean seed equivalent to 0.5 percent w/w. Antidote compounds may also be applied as liquid slurries and powders or dusts.In some cases, acetone is used to dissolve powdered or solid compounds so they could be more effectively applied to the seeds.

After the flats were seeded, they were covered with the one pint of soil which had been removed just prior to planting. Flats were placed on greenhouse benches where temperatures ranged from 70 to 900F. Flats were watered by sprinkling as needed to ensure good plant growth. Percent control ratings were taken four weeks after the treatments were applied.

In each test, the herbicide was applied alone, in combination with the seed protectant and the seed protectant was applied alone to check for phytotoxicity.

The untreated adjacent row was employed to observe any beneficial lateral movement of the antidote compound through the soil. The degree of the effect was noted by comparison with the control.

In this seed treatment test with the herbicide S-n-propyl N,N-di-n-propyl thiolcarbamate, compound number 5 exhibited 50 percent protection to the treated soybean seeds. That is, the injury was reduced by at least 50 percent to the emerging soybean plants grown from seed treated with compound number 5 compared to untreated seed grown in soil containing the thiolcarbamate herbicide.

The compounds and compositions according to the present invention were employed in effective herbicidal compositions comprising the antidote and a representative thiolcarbamate herbicide as described above. The herbicidal compositions were tested in the following manner.

The compositions according to the present invention for the protection of cultivated crop plants comprise an active herbicidal compound and an antidote therefor selected from the above-described compounds. The compositions of herbicide and antidote may be prepared by conventional methods by the thorough mixing and grinding of the active herbicide agents and the antidote with suitable carriers and/or other distribution media, possibly with the addition of dispersion agents or solvents.

The antidote compounds and compositions according to the present invention may be used in any convenient form. Thus, the antidote compounds may be formulated into, for example, emulsifiable liquids, emulsifiable concentrates, liquid, wettable powder, powders or granulates. In its preferred form, a nonphytotoxic quantity of an herbicidal antidote compound is admixed with a selected herbicide and incorporated into the soil prior to or after planting the seed. It is to be understood, however, that the herbicides may be incorporated into the soil and thereafter the antidote compound may be incorporated into the soil. Moreover, the crop seed itself may be treated with a non-phytotoxic quantity of the antidote compound and planted into the soil which has been treated with herbicides, or it may be planted in untreated soil which is subsequently treated with the herbicide.

The addition of the antidote compound does not affect the herbicidal activity of the herbicides.

The amount of antidote compound present may range from 0.001 to 30 parts, by weight, of antidote compound per part, by weight, of herbicide. The exact amount of antidote compound will usually be determined on economic ratios for the most effective amount usable. It is understood that a non-phytotoxic quantity of antidote compound will be employed in the herbicidal compositions described herein.

WHAT WE CLAIM IS: 1. A composition comprising a thiolcarbamate herbicide and an antidotally effective amount of a compound corresponding to the following general formula:

wherein X represents methyl, chloro, bromo or methoxy; n represents 0, 1, 2 or 3; R1 represents hydrogen or methyl; and R2 represents C1-C4 alkyl, benzyl, 4-chlorophenyl or methylenethio-p chlorobenzene sulphonyl carbamate; provided that when n represents 0 and R1 represents methyl, then R2 represents other than ethyl.

2. A composition comprising a thiolcarbamate herbicide and an antidotally effective amount of a compound corresponding to the following general formula:

3. A composition comprising S - n - propyl - di - n - propylthiolcarbamate and an antidotally effective amount of a compound corresponding to the following general formula:

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. The antidote compounds and compositions according to the present invention may be used in any convenient form. Thus, the antidote compounds may be formulated into, for example, emulsifiable liquids, emulsifiable concentrates, liquid, wettable powder, powders or granulates. In its preferred form, a nonphytotoxic quantity of an herbicidal antidote compound is admixed with a selected herbicide and incorporated into the soil prior to or after planting the seed. It is to be understood, however, that the herbicides may be incorporated into the soil and thereafter the antidote compound may be incorporated into the soil. Moreover, the crop seed itself may be treated with a non-phytotoxic quantity of the antidote compound and planted into the soil which has been treated with herbicides, or it may be planted in untreated soil which is subsequently treated with the herbicide. The addition of the antidote compound does not affect the herbicidal activity of the herbicides. The amount of antidote compound present may range from 0.001 to 30 parts, by weight, of antidote compound per part, by weight, of herbicide. The exact amount of antidote compound will usually be determined on economic ratios for the most effective amount usable. It is understood that a non-phytotoxic quantity of antidote compound will be employed in the herbicidal compositions described herein. WHAT WE CLAIM IS:

1. A composition comprising a thiolcarbamate herbicide and an antidotally effective amount of a compound corresponding to the following general formula:

wherein X represents hydrogen, methyl, chloro, bromo or methoxy; R, represents hydrogen or methyl; and R2 represents C1-C4 alkyl, benzyl, or 4-chlorophenyl; provided that when X represents hydrogen and R, represents methyl, then R2 represents other than ethyl.

4. A composition as claimed in Claim 1 in which the said thiolcarbamate herbicide is selected from S - n - propyl - N,N - di - n - propylthiolcarbamate, S- ethyl - di- propylthiolcarbamate and S- ethyl - cyclohexyl- ethyl thiolcarbamate.

5. A composition as claimed in Claim 1 comprising a compound corresponding to the general formula defined in Claim 1, wherein Xn represents 2,4,6-methyl; R, represents hydrogen; and R2 represents alkyl.

6. A composition as claimed in Claim 1 comprising a compound corresponding to the general formula defined in Claim 1 which is either the compound numbered 11 or the compound numbered 12 listed hereinbefore.

7. A composition as claimed in Claim 3 comprising a compound corresponding to the general formula defined in Claim 3, wherein X represents methyl, R, represents hydrogen; and R2 represents alkyl.

8. A composition as claimed in Claim 3 comprising a compound corresponding to the general formula defined in Claim 3, wherein X represents hydrogen; R, represents hydrogen; and R2 represents alkyl.

9. A composition as claimed in Claim 3 comprising a compound corresponding to the general formula defined in Claim 3, wherein X represents chloro; R, represents methyl; and R2 represents alkyl.

10. A composition as claimed in Claim 3 comprising a compound corresponding to the general formula defined in Claim 3, wherein X represents chloro; R, represents hydrogen; and R2 represents alkyl.

11. A composition as claimed in Claim 3 comprising a compound corresponding to the general formula defined in Claim 3, wherein X represents methoxy; R, represents hydrogen; and R2 represents alkyl.

12. A composition as claimed in Claim 3 comprising a compound corresponding to the general formula defined in Claim 3, wherein X represents bromo; R, represents hydrogen; and R2 represents alkyl.

13. A composition as claimed in Claim 3 comprising a compound corresponding to the general formula defined in Claim 3 which is one of the compounds numbered I to 10 listed hereinbefore.

14. A composition as claimed in any of Claims 1 to 3 which also comprises an inert carrier or diluent.

15. A composition as claimed in any of Claims I to 3 which comprises from 0.001 to 30 parts, by weight, of antidote per part, by weight, of herbicide.

16. A composition as claimed in Claim 1 substantially as herein described.

17. A composition as claimed in Claim 1 substantially as herein described with reference to the testing procedures.

18. A composition as claimed in Claim 2 substantially as herein described.

19. A composition as claimed in Claim 2 substantially as herein described with reference to the testing procedures.

20. A composition as claimed in Claim 3 substantially as herein described.

21. A composition as claimed in Claim 3 substantially as herein described with reference to the testing procedures.

22. A method of controlling vegetation which comprises applying to the locus where the said control is desired a composition as claimed in Claim 1.

23. A method as claimed in Claim 22 substantially as herein described.

24. A method as claimed in Claim 22 substantially as herein described with reference to the testing procedures.

25. A method of controlling vegetation which comprises applying to the locus where the said control is desired a composition as claimed in Claim 2.

26. A method as claimed in Claim 25 substantially as herein described.

27. A method as claimed in Claim 25 substantially as herein described with reference to the testing procedures.

28. A method of controlling vegetation which comprises applying to the locus where the said control is desired a composition as claimed in Claim 3.

29. A method as claimed in Claim 28 substantially as herein described.

30. A method as claimed in Claim 28 substantially as herein described with reference to the testing procedures.

31. A method of protecting a plant crop from injury due to a thiolcarbamate herbicide which comprises applying to the soil in which the crop is to be planted, prior to planting, a non-phytotoxic antidotally effective amount of a compound corresponding to the general formula defined in Claim 1.

32. A method of protecting a plant crop from injury due to a thiolcarbamate herbicide which comprises applying to the soil in which the crop is to be planted, prior to planting, a non-phytotoxic antidotally effective amount of a compound corresponding to the general formula defined in Claim 2.

33. A method of protecting a plant crop from injury due to S - n - propyl di - n - propylthiolcarbamate which comprises applying to the soil in which the crop is to be planted, prior to planting, a non-phytotoxic antidotally effective amount of a compound corresponding to the general formula defined in Claim 3.

34. A method as claimed in Claim 33 in which the plant crop is soybeans.

35. A method as claimed in any of Claims 31 to 34 substantially as herein described.

36. A method as claimed in any of Claims 31 to 34 substantially as herein described with reference to the testing procedures.

37. A method of protecting a crop from injury due to a thiolcarbamate herbicide selected from S - n - propyl - N,N - di - n - propylthiolcarbamate S ethyl - dipropyl- thiolcarbamate and S- ethyl - cyclohexyl- ethyl thiolcarbamate which comprises applying to the soil in which a herbicidally effective amount of the thiolcarbamate is used or is to be used a non-phytotoxic amount of a compound corresponding to the general formula defined in Claim 1.

38. A method as claimed in Claim 37 substantially as herein described.

39. A method as claimed in Claim 37 substantially as herein described with reference to the testing procedures.

40. A method of protecting a plant crop from injury due to a thiolcarbamate herbicide which comprises applying to the plant seed, prior to planting, a nonphytotoxic antidotally effective amount of a compound corresponding to the general formula defined in Claim 1.

41. A method of protecting a plant crop from injury due to a thiolcarbamate herbicide which comprises applying to the plant seed, prior to planting, a nonphytotoxic antidotally effective amount of a compound corresponding to the general formula defined in Claim 2.

42. A method of protecting a plant crop from injury due to S - n - propyl di - n - propylthiolcarbamate which comprises applying to the plant seed, prior to planting a non-phytotoxic antidotally effective amount of a compound corresponding to the general formula defined in Claim 3.

43. A method as claimed in any of Claims 40 to 42 substantially as herein described.

44. A method as claimed in any of Claims 40 to 42 substantially as herein described with reference to the testing procedures.

45. A crop seed having applied thereto a compound corresponding to the general formula defined in Claim 1.

46. A seed as claimed in Claim 45 which is a soybean seed.

47. A seed as claimed in Claim 45 substantially as herein described.

48. A seed as claimed in Claim 45 substantially as herein described with reference to the testing procedures.

49. A crop seed having applied thereto a compound corresponding to the general formula defined in Claim 3.

50. A seed as claimed in claim 49 which is a soybean seed.

51. A seed as claimed in Claim 49 substantially as herein described.

52. A seed as claimed in Claim 49 substantially as herein described with reference to the testing procedures.

53. A compound corresponding to the following general formula:

wherein X represents methyl, chloro, bromo or methoxy; n represents 0, 1, 2 or 3; R1 represents hydrogen or methyl; R2 represents C24 alkyl, benzyl 4-chlorophenyl, or methylenethio - p chlorobenzene sulphonyl carbamate; provided that when X represents methyl, then R2 represents other than alkyl; and when n represents 0 and R represents methyl, then R2 represents other than ethyl.

54. A compound corresponding to the following general formula:

wherein X represents hydrogen, methyl, chloro, bromo or methoxy; R, represents hydrogen or methyl; and R2 represents C2-C4 alkyl, benzyl, or 4-chlorophenyl; provided that when X represents methyl, then R2 represents other than alkyl; and, when X represents hydrogen and R1 represents methyl then R2 represents other than ethyl.

55. A compound corresponding to the general formula defined in Claim 53, wherein Xn represents 2,4,6-methyl; R, represents hydrogen; and R2 represents alkyl.

56. A compound corresponding to the general formula defined in Claim 53 which is the compound numbered 11 or the compound numbered 12 listed hereinbefore.

57. A compound corresponding to the general formula defined in Claim 54, wherein X represents hydrogen; R1 represents hydrogen; and R2 represents alkyl.

58. A compound corresponding to the general formula defined in Claim 54, wherein X represents chloro; R, represents methyl; and R2 represents alkyl.

59. A compound corresponding to the general formula defined in Claim 54, wherein X represents chloro; R, represents hydrogen; and R2 represents alkyl.

60. A compound corresponding to the general formula defined in Claim 54, wherein X represents methoxy; R1 represents hydrogen; and R2 represents alkyl.

61. A compound corresponding to the general formula defined in Claim 54, wherein X represents bromo; R, represents hydrogen; and R2 represents alkyl.

62. A compound corresponding to the general formula defined in Claim 54 which is one of the compounds numbered 2 to 10 listed hereinbefore.

63. A compound corresponding to the general formula defined in Claim 53 substantially as herein described.

64. A compound corresponding to the general formula defined in Claim 53 substantially as herein described with reference to any of the Examples.

65. A compound corresponding to the general formula defined in Claim 54 substantially as herein described.

66. A compound corresponding to the general formula defined in Claim 54 substantially as herein described with reference to any one of the Examples.

67. A process for the preparation of a compound corresponding to the general formula defined in Claim 53 substantially as herein described.

68. A process for the preparation of a compound corresponding to the general formula defined in Claim 53 substantially as herein described with reference to any one of the Examples.

69. A compound when prepared by a process as claimed in Claim 67 or Claim 68.

70. A process for the preparation of a compound corresponding to the general formula defined in Claim 54 substantially as herein described.

71. A process for the preparation of a compound corresponding to the general formula defined in Claim 54 substantially as herein described with reference to any one of the Examples.

72. A compound when prepared by a process as claimed in Claim 70 or 71.